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The Role of the United States Military in the Development of Vector Control Products, Including Insect Repellents, Insecticides, and Bed Nets
Abstract
Arthropod-borne diseases such as malaria, dengue, scrub typhus, and leishmaniasis continue to pose a significant threat to U.S. military forces deployed in support of operational and humanitarian missions. These diseases are transmitted by a variety of arthropods, including mosquitoes, ticks, chiggers, sand flies, and biting midges. In addition to disease threats, biting arthropods can cause dermatitis, allergic reactions, and sleep loss; therefore, monitoring of vector impact and integrated use of personal protective measures (PPM) and methods to reduce the vector populations are needed to protect service members. The U.S. military has played a vital role in vector identification tools and the development and testing of many of the most effective PPM and vector control products available today, including the topical repellent DEET and the repellent/insecticide permethrin, which is applied to clothing and bed nets. Efforts to develop superior products are ongoing. Although the U.S. military often needs vector control products with rather specific properties (e.g., undetectable, long-lasting in multiple climates) in order to protect its service members, many Department of Defense vector control products have had global impacts on endemic disease control.
... Most of the repellents and insecticide spraying systems currently in use were designed and introduced for use by the armed forces. During World War II, the United States Armed Forces worked on new repellents, such as dimethyl phthalate and indalone, in addition, the repellent DDT (dichlorodiphenyltrichloroethane) was developed [78,79,84]. Additionally, the effectiveness of permethrin-impregnated field uniforms against arthropod stings has been evaluated in a field studies. ...
... The US Army has responded to the threat from vector-borne infectious diseases since the early part of the 20th century. This is the area by the study of Major Walter Reed and other researchers investigating the transmission routes of the yellow fever virus [84]. ...
... These initial successes in the field of medical entomology prepared the ground for subsequent efforts by the US Army to control vectors and prevent vector-borne diseases, which expanded during World War II. The US combat experience led to the appointment of military entomologists and the establishment of vector-borne disease control units [84,85]. When Poland joined NATO in 1999, it committed itself to adopting common principles of the organisation, including in the area of medical security. ...
Introduction and objective:
Mosquitoes are the most important vector group for humans, and three genera – Aedes, Anopheles and Culex, are of greatest significance in the transmission of pathogens to humans and animals. The geographical expansion of vectors can lead to the spread diseases into new regions. Soldiers exercise in the field, participate in missions, or are stationed in Military Contingents located in different climatic conditions, which is directly related to exposure to mosquitoborne diseases.
Objective:
The aim is to describe the role of mosquitoes in the transmission of selected pathogens of medical and epidemiological importance, which pose a new threat in Europe, pointing to soldiers and other military personnel as particularly vulnerable occupational groups.
Review Methods:
PubMed and other online resources and publications were searched to evaluate scientific relevance.
Brief description of the state of knowledge.:
In recent years in Europe, attention has been drawn to emerging infectious diseases transmitted by mosquitoes, including malaria, Dengue fever, West Nile fever and Chikungunya fever. West Nile virus infections were recorded in many European countries, including Greece, Italy, Germany and Austria. Soldiers, due to their tasks, are particularly vulnerable to vector-borne diseases. In order to reduce the exposure of soldiers to mosquito-borne diseases various protection measures are used.
Summary:
Some of vector-borne diseases belong to emerging infectious diseases and may pose a threat to public health. The burden on soldiers with these diseases can be significant, which is the reason why methods of surveillance and the control of vectors are being developed.
... This may be the reason why the 4 g/L permethrintreated fabrics had much lower TPC and SPC because permethrin did not bind with the fabric. Other have shown that fire-resistant uniforms do not uniformly absorb permethrin and different types of fabrics and treatments could also be evaluated in the future [30]. This type of information is important for those interested in improving the efficacy of PTC for public health protection. ...
... It is possible that continued permethrin exposure through additional mosquito generations could lead to a permethrin-resistant colony and further studies are warranted to evaluate this. While beyond the scope of the current study, future studies could also conduct arm-in-cage tests using human volunteers to compare the extent to which mosquito repellency differs between fabrics and repellants such as DEET and others [30,31]. Furthermore, additional types of insecticide-treated fabrics and combinations of repellents and insecticides could be evaluated (e.g. ...
... Furthermore, additional types of insecticide-treated fabrics and combinations of repellents and insecticides could be evaluated (e.g. tents, bednets) to improve PTC that could further protect health [30,32,33]. ...
Permethrin is a synthetic pyrethroid insecticide used to treat uniforms (e.g. military, foresters) and other clothing to protect people against pests (e.g., mosquitoes, ticks). Pests contacting the surface of permethrin-treated clothing (PTC) are repelled and/or killed, depending on the dose and duration of exposure. Hence, it is important to assess the amount of permethrin on the surface of clothing. Fabric swatches prepared using two commercially available permethrin treatments (Insect Shield® & Sawyer Repellant) and one laboratory created treatment (4g permethrin/L) were tested. A Martindale Abrasion and Pilling Tester (MAPT) and gas chromatography were used to assess surface permethrin content (SPC) and total permethrin content (TPC). Sawyer PTC had the highest SPC (mean ± standard error) (32.68±14.55µg/g), followed by Insect Shield® (23.35±2.71µg/g) and lab-created 4g/L permethrin (8.7±0.78µg/g). SPC (after 1000 rubs on MAPT) for Insect Shield®, Sawyer, and 4g/L permethrin groups was significantly lower than TPC (P=0.011, P<0.001, and P=0.001, respectively). The SPC/TPC relationship varied widely between permethrin treatment methods and practical implications for this are discussed. Mosquito repellency tests indicate that Insect Shield®, Sawyer, and lab-created (4g/L) permethrin-treated fabrics showed a significantly higher repellency rate than control (untreated) fabrics (P=0.001, P<0.0001, P<0.0001, respectively). While Insect Shield® had the highest repellency rate against susceptible (53%) and exposed (48%) mosquitoes, differences between groups were not significant. Repellency rates indicate SPC plus other factors (e.g. treatment method) may contribute to mosquito repellency and should be considered in risk assessments for protection against pests.
... It is used in the form of skin creams for the treatment of human head lice and scabies. However, skin application makes it ineffective as an insecticide/repellent as it does not bond to human skin (Kitchen et al. 2009). Characteristics such as excito-repellency, 'hot-feet', knock-down (KD) effect, lethality and residual efficacy of permethrin have made it a preferred active ingredient in IF (Faulde et al. 2016). ...
... Repellent-treated uniforms have been used by the forces since the Second World War though the earlier used repellents such as dimethyl phthalate and DEET (N, N-diethyl-mtoluamide) were later replaced by permethrin-a synthetic pyrethroid insecticide (Pennetier et al. 2010). Currently, the armed forces of many countries across the world are using permethrin-treated military uniforms to protect their personnel from vector-borne infections (Frances et al. 2014;Kitchen et al. 2009;Most et al. 2017;Pennetier et al. 2010). Permethrin treatment of clothing is recommended by WHO as a method of protection from disease vectors (Rozendaal 1997). ...
... Initially, insecticidal treatment of military uniforms was done by spraying or dipping and consequently, the residual efficacy was low (Most et al. 2017). Evaluation of permethrin as a clothing repellent was initiated by the US Department of Defense (DoD) in association with the Department of Agriculture (USDA) (Kitchen et al. 2009). Studies were carried out on the efficacy of permethrin sprays on clothing against the lone star tick (Schreck et al. 1982). ...
Insecticidal fabrics are effective personal protective measures against disease vectors and unlike bed nets, these fabrics can provide protection from day-biting mosquitoes and in outdoor environments. The rapid geographical expansion of day-biting mosquitoes and their role in disease transmission necessitate technological interventions, which can be effectively used during the daytime. There is a renewed interest in insecticidal fabrics mainly due to the recent outbreaks and geographical spread of dengue and chikungunya and with the emerging threat of Zika virus infection. Insecticidal fabrics are useful for protection from night-biting mosquitoes and also in situations were sleeping under a bed net is not possible. They are also effective against other biting arthropods like ticks, mites, tsetse flies, sand flies and body lice. Although long-lasting insecticidal fabrics factory-treated with permethrin are now commercially available for military and civilian use, there are no international guidelines for testing their efficacy. The different methods employed so far for testing bioefficacy, washing and quantification of permethrin are compiled in this review. The future prospects and challenges ahead for long-lasting insecticidal fabrics are discussed in the context of the increased threat from day-biting mosquitoes and the diseases transmitted by them. The review focuses on the need for standardisation of the test methods for ensuring adequate bioefficacy and safety to the user. The differences between long-lasting insecticidal nets and long-lasting insecticidal fabrics are elaborated, and the need for a separate registration and licencing procedure for long-lasting insecticidal fabrics is highlighted. A test procedure for insecticidal fabrics is described, which could be used until internationally accepted guidelines are available.
... DEET was developed in 1946 in the USA to guard the troops deployed from mosquito bites and related diseases [87,88], and thereafter made available to the public in 1957 as active ingredient of insect repellents. This can be found in spray, lotion for skin, in clothes and nets to guard against diseases transferred by vector bites and in prevalent areas [87,89] and antifeedant [90]. ...
... DEET was developed in 1946 in the USA to guard the troops deployed from mosquito bites and related diseases [87,88], and thereafter made available to the public in 1957 as active ingredient of insect repellents. This can be found in spray, lotion for skin, in clothes and nets to guard against diseases transferred by vector bites and in prevalent areas [87,89] and antifeedant [90]. Merel [91] reviewed that DEET is one of the most commonly detected organic chemical contaminants in water. ...
PPCPs are found almost everywhere in the environment especially at an alarming rate and at very low concentration in the aquatic systems. Many methods—including pressurized hot water extraction (PHWE), pressurized liquid extraction (PLE), ultrasound-assisted extraction (UAE), and micro-assisted extraction (MAE)—have been employed for their extraction from both surface waters and biota. Solid-phase extraction (SPE) proved to be the best extraction method for these polar, non-volatile, and thermally unstable compounds in water. However, ultrasonic extraction works better for their isolation from sediment because it is cheap and consumes less solvent, even though SPE is preferred as a clean-up method for sediment samples. PPCPs are in groups of—acidic (e.g., diclofenac, ibuprofen, naproxen), neutral (e.g., caffeine, carbamazepine, fluoxetine), and basic pharmaceuticals, as well as antibiotics and estrogens amongst others. PPCPs which are present in trace levels (ng/L) are more often determined by liquid chromatography-mass spectrometry (LC-MS), gas chromatography-mass spectrometry (GC-MS), and high-performance liquid chromatography-ultraviolent (HPLC-UV). Of these, LC-MS and LC-MS-MS are mostly employed for the analysis of this class of compounds, though not without a draw-back of matrix effect. GC-MS and GC-MS-MS are considered as alternative cost-effective methods that can also give better results after derivatization.
... Zika virus has recently acquired prominence due to its dreaded fatal consequences. Millions of people worldwide are afflicted by these infections leading to hundreds of deaths annually, mainly transmitted by the Aedes aegypti species of mosquitos [1,2]. The impact is enormous. ...
... tional Center for Medical Intelligence indicated that the likelihood of infections from mosquito-borne diseases are responsible for the top 40 endemic threats." [2]. Mosquitoes top the list in disease transmission, since they cause more human suffering by their bloodfeeding behavior than any other organism. ...
Background:
In view of many current mosquito-borne diseases there is a need for the design of novel repellents.
Objective:
The objective of this article is to review the research of results carried out by the authors in the computer-assisted design of novel mosquito repellents.
Method:
Two methods in the computational design of repellents have been discussed: a) Quantitative structure activity relationship (QSAR) studies from a set of repellents structurally related to DEET using computed mathematical descriptors, and b) Pharmacophore based modeling for design and discovery of novel repellent compounds including virtual screening of compound databases and synthesis of novel analogues.
Results:
Effective QSARs could be developed using mathematical structural descriptors. The pharmacophore based method is an effective tool for the discovery of new repellent molecules.
Conclusion:
Results reviewed in this article show that both QSAR and pharmacophore based methods can be used in the design of novel repellents.
... Ce fut la découverte du rôle des vecteurs dans la transmission des maladies au début de XXe siècle qui permis aux armées de mieux cibler la menace. Ainsi en 1901, l'armée américaine découvrit que la fièvre jaune était transmise par les moustiques du genre Aedes (Kitchen et al, 2009). Ceci permit de mettre en place la lutte mécanique avec la destruction des gîtes de pontes, mais aussi la protection personnelle en utilisant des vêtements couvrants (Pagès, 2009). ...
... Cependant, ces précautions restent insuffisantes. Aujourd'hui, les troupes américaines interviennent dans plus de 130 pays comprenant de nombreuses régions où les vecteurs de maladies sont répandus (Kitchen et al, 2009), la majorité des forces françaises est déployée en Afrique et dans les régions d'outre-mer (Deparis et al, 2001) (Figure 8). En absence de traitements prophylactiques efficaces pour l'ensemble des maladies transmissibles, l'amélioration constante des stratégies de LAV reste la seule défense pour les troupes armées autant que pour les civils. ...
Actuellement, la plupart des textiles utilisés pour limiter les contacts avec les moustiques vecteurs de maladies sont imprégnés d’insecticides pyréthrinoïdes possédant une action insecticide et répulsive. Cependant, l’apparition de résistances au sein des populations de moustiques remet en cause cette efficacité.La nouvelle stratégie de lutte contre les moustiques s’appuie sur l’effet synergique obtenu lors d’une association de deux molécules de familles chimiques différentes à effet insecticide et répulsif. Les effets de deux répulsifs, le DEET et l’IR3535 ont été étudiés sur des cellules neurosecrétrices isolées du système nerveux central de la blatte Periplaneta americana. A l’aide de la technique d’imagerie calcique, il a été possible de montrer que ces composés induisent une augmentation dose-dépendante complexe de la concentration en calcium intracellulaire. L’utilisation d’outils pharmacologiques spécifiques a permis de caractériser les cibles et les évènements moléculaires impliqués dans ces effets. A partir de ces résultats, l’IR3535 s’est avéré être le meilleur répulsif pour une association avec un insecticide néonicotinoïde, le thiaclopride. Grâce à la technique électrophysiologique du patch-clamp adaptée sur neurones d’insecte, l’effet synergique produit par l’association IR3535/thiaclopride a été observé et le rapport de concentrations répulsif/insecticide qui donne le meilleure effet synergique sur le courant entrant induit par le thiaclopride déterminé. Des tests en cône réalisés sur moustiques in vivo ont confirmé cet effet synergique,démontrant l’intérêt de proposer l’associationIR3535/thiaclopride comme nouvelle stratégie de lutte anti-vectorielle.
... US soldiers returning from Iraq reported high vector exposure, with hundreds of insect bitesdparticularly insect bites that took a long time to heal [3]. Even asymptomatic infections in soldiers are considered of medical significance because these might cause subsequent disease in individuals who become immunosuppressed because of other diseases later in their lives, because of HIV infection, or because of chemotherapy [22]. At least in dogs, Leishmania is known to survive in the host, possibly for the rest of the animal's life, and even after successful treatment. ...
... Even asymptomatic infections are of clinical relevance, as latent infections may resurge in case of an emerging immunodeficiency. Personal protection, such as insecticideimpregnated (permethrin) uniforms worn properly (long sleeves and long trousers), insect repellents or insecticide-impregnated bed nets and curtains have proven to be effective [22,25]. Adequate prevention measures during recreational activities also seem particularly important. ...
Objectives:
The incidence of leishmaniasis is known to increase in conflict areas. The aim of this study was to determine the exposure to Leishmania species in Austrian soldiers returning from missions abroad also assessing possible risk factors.
Methods:
A retrospective explorative cross-sectional serological study was conducted in 225 healthy Austrian soldiers returning from UN or EU peace-keeping missions in Syria, the Lebanon and Bosnia and Herzegovina (BIH), respectively. Sera were tested for anti-Leishmania antibodies using a commercial ELISA. All positive individuals were screened for Leishmania DNA by PCR targeting the ITS1 region using EDTA blood samples.
Results:
In total, 13.3% (30/225) of the individuals tested were either positive (8%=18/225) or borderline (5.3%=12/225) in the ELISA, with highest seroprevalence in soldiers returning from Syria (17.8%=18/101; 12 positive, 6 borderline), second from the Lebanon (11.1%=7/63; 4 positive, 3 borderline), and lowest from BIH (8.2%=5/61; 2 positive, 3 borderline). Ten soldiers returning from Syria and one from BIH were also positive for Leishmania DNA. Six of these were identified as Leishmania donovani/infantum complex, two as L. tropica, and another three as mixed infections by DNA sequencing. Epidemiological data were collected with a questionnaire, seropositivity correlated with a history of lengthy-healing insect bites (OR 5.33, 95% CI 1.23-23.04, p = 0.025).
Conclusions:
Although, pre-travel serological data was not available in this study, the exposure of soldiers to Leishmania spp. during their missions can be assumed to be considerable. As even asymptomatic infections may resurge in case of emerging immunodeficiencies, adequate prevention measures seem important.
... Personal protective methods, such as the use of repellents, are important means of reducing exposure of military troops to vector populations. 12 Although DEET is safe for cotton, wool, and nylon fabrics, it can dissolve plastic on eye glasses, watch crystals, and protective mask eyepieces. Some DEET users have an oily and burning sensation when it is applied to the skin (irritant contact dermatitis). ...
... Some DEET users have an oily and burning sensation when it is applied to the skin (irritant contact dermatitis). 12 Over 62% of 1500 soldiers who responded to a questionnaire urged the Army to obtain a better repellent. 13 As a result of these concerns, there is a need to identify and develop alternatives to complement the currently available synthetic repellents for protection against a wide variety of insect-vectored diseases. ...
Tick-borne diseases, such as Lyme disease and Rocky Mountain spotted fever still constitute a serious problem for thousands of Americans. The principal vectors are three-host ticks that use a variety of vertebrate hosts associated with forested habitats. Synthetic repellents, in particular DEET (N,N-diethyl-3-methyl benzamide)-based products still represent the major chemical defense against ticks [1], but there are concerns about the safety of these products. DEET has been associated with seizures and encephalopathy in children, and parents and caregivers are nervous about the effect of repellents on their children's sensitive skin. For these reasons, new and safer alternatives are needed. Natural products, and essential oil in particular, are usually regarded as a safer and “greener” alternative to synthetic compounds and many natural compounds are known for their repellency properties. Nonetheless, essential oils still constitute an unexplored source of tick repellents. Geranium (Pelargonium graveolens) essential oil is widely known for its anti-mosquito activity. Although insecticidal and repellent activities of geranium oil have been previously reported [2], no reports about the active compounds from geranium essential oil as active tick repellents have been published.
In the current investigation, bio-guided fractionation of geranium essential oil has been performed. Several active constituents have been identified. In particular, the authors report here for the first time the biological activity of (-)-10-epi-γ-eudesmol (1) as active tick repellent.
Acknowledgements: This study was supported in part the USDA, ARS grant No. 56 – 6402 – 1-612 and Deployed War-Fighter Protection Research Program Grant funded by the U.S. Department of Defense through the Armed Forces Pest Management Board. The authors thank Agilent Technologies, Inc. (Santa Clara CA, USA) for provision of the analytical instrumentation used in this study. References: [1] Debboun M, Frances et al. (2007) “Insect Repellents: Principles, Methods and Uses”, CRC Press LLC [2] Jaenson TGT, Garboui S, Palsson K (2006)J Med Entomol, 43: 731 – 736.
... flagellum). When a host is inappropriate, parasites are discharged with the excrement [19]. When the blood meal is digested, trypanosomatids such as Leshmania species and others bind to the parasites on the midgut epithelium. ...
Cutaneous leishmaniasis (CL) is a widespread parasitic infection caused by the Leishmania, which is carried by female sandflies. The symptoms include basic ulcer to lethal systemic disease i.e., formation of widely dispersed skin lesions of diverse types. Almost 350 million individuals are at danger and the disease is endemic in more than 98 countries. There are globally 12 million cases, with 2–2.5 million new cases annually. Cutaneous leishmaniasis is considered as critically neglected disease by WHO. Earlier it was difficult to identify the infecting parasite, but modern DNA techniques make it quite simple to identify the Leishmania species, allowing quick treatment decisions. The quick identification of Leishmania is made possible using the PCR method. There is currently no vaccination to prevent leishmaniasis, and pharmacological treatment is frequently ineffectual. There is a need for broad and well-conducted investigations to help its control. Amphotericin B, pentamidine isethionate, paromomycin, and antifungals are some of the drugs recommended for treatment. By organising direct, in-person training, which is a crucial step in improving attitudes and preventative actions toward CL and its control in endemic areas, it is necessary to underline the significance and necessity of teaching this at-risk population.
... Arthropod-borne diseases, such as malaria, dengue, scrub typhus and leishmaniasis, continue to pose a significant threat to deployed U.S. military forces. Biting arthropods not only transmit disease (Riddle et al., 2008), but as persistent pests they can inflict painful and distracting bites that may lead to secondary infections, dermatitis, or allergic reactions (Kitchen et al., 2009). Traditional methods used to minimize exposure include application of residual insecticides on tents and buildings: use of barrier sprays, ultralow volume (ULV) or thermal fogging applications of insecticides and use of personal protective measures (PPM), such as the application of topical insect repellent on exposed skin, wearing permethrin-treated uniforms, and the use of insecticide-treated bednets (Maroli & Khoury, 2004;Coleman et al., 2006). ...
Mosquitoes can impact military operational readiness by transmission of disease-causing pathogens or through secondary effects, e.g., annoyance and bites. The focus of this research was to determine if an array of novel controlled release passive devices (CRPD) utilizing the spatial repellent, transfluthrin (TF), as the active ingredient could prevent entry of mosquitoes into military tents for up to 4 weeks. The TF-charged CRPDs were spaced along six strands of monofilament and hung across the tent entrance. Efficacy was evaluated with caged Aedes aegypti to indicate knockdown/mortality effects, and four species of free-flying mosquitoes, Ae. aegypti, Aedes taeniorhynchus, Anopheles quadrimaculatus and Culex quinquefasciatus, to indicate repellent effects. Bioassay cages containing Ae. aegypti were hung vertically at 0.5, 1.0 and 1.5 m above ground level at designated locations inside of the tents. Knockdown/mortality counts were made every 15 minutes for the first hour, then at 2, 4 and 24 hours post-exposure. Free fliers were recaptured in BG traps operated from 4 to 24 hours post-exposure. Knockdown/mortality was gradual until 4 hours post-exposure. This increased to near 100% by 24 hours in the treated tent but was <2% in the control tent. There was a significant reduction in the recapture rates of all free-flying species in the treated tent compared with the control tent. Results indicate that TF-charged CRPDs can significantly reduce the numbers of mosquitoes entering military tents and that the four species were affected similarly by the TF. The needs for additional research are discussed.
... Introduction N,N-diethyl-m-toluamide (DEET), the major active ingredient of common topical insect repellents, was first developed by the US Department of Agriculture as protection for the military in 1946 and registered for general public use in 1957 (1,2). Numerous studies have confirmed that DEET is the most effective repellent for biting insects, mosquitoes, and ticks (3)(4)(5)(6). ...
Although growing evidence suggests that N,N-diethyl- m- toluamide (DEET) has adverse effects on public health, the relationship of DEET with cardiovascular disease (CVD) is still largely unknown. The purpose of this study was, therefore, to evaluate the association between DEET exposure and total and specific CVD among the US adults. In this cross-sectional study, a total of 5,972 participants were selected from the National Health and Nutrition Examination Survey (NHANES) 2007–2014. CVD was defined as a combination of congestive heart failure (CHF), coronary heart disease (CHD), angina, heart attack, or stroke. Logistic regression models were used to evaluate the association between DEET metabolites and the risks of total and specific CVD. Compared to the lowest quartile, 3-(diethylcarbamoyl) benzoic acid (DCBA) in the highest quartile was associated with the increased risks of CVD (odds ratio [OR]: 1.32, 95% CI: 1.03–1.68, P for trend = 0.025) and CHD (OR: 1.57, 95% CI: 1.10–2.25, P for trend = 0.017), after adjustment for potential covariates. Nevertheless, exposure to DCBA was not significantly associated with heart attack, CHF, angina, and stroke. Further studies are required to confirm these findings and identify the underlying mechanisms.
... The interest for the military is linked to missions in at-risk areas, the type of activity, and the compliance with personal protective measures. In addition to the contribution of British military physicians in the first description of the parasite, the US military researchers provided relevant original contributions in the field of personal protective and vector control measures [377] and on the best conditions for the use of diagnostic and therapeutic tools [368]. The incidence rate of leishmaniasis among the US military was 7.2 cases per 100,000 person-years between 2001 and 2016, with the majority of cases being cutaneous leishmaniasis [378]. ...
The environmental conditions generated by war and characterized by poverty, undernutrition, stress, difficult access to safe water and food as well as lack of environmental and personal hygiene favor the spread of many infectious diseases. Epidemic typhus, plague, malaria, cholera, typhoid fever, hepatitis, tetanus, and smallpox have nearly constantly accompanied wars, frequently deeply conditioning the outcome of battles/wars more than weapons and military strategy. At the end of the nineteenth century, with the birth of bacteriology, military medical researchers in Germany, the United Kingdom, and France were active in discovering the etiological agents of some diseases and in developing preventive vaccines. Emil von Behring, Ronald Ross and Charles Laveran, who were or served as military physicians, won the first, the second, and the seventh Nobel Prize for Physiology or Medicine for discovering passive anti-diphtheria/tetanus immunotherapy and for identifying mosquito Anopheline as a malaria vector and plasmodium as its etiological agent, respectively. Meanwhile, Major Walter Reed in the United States of America discovered the mosquito vector of yellow fever, thus paving the way for its prevention by vector control. In this work, the military relevance of some vaccine-preventable and non-vaccine-preventable infectious diseases, as well as of biological weapons, and the military contributions to their control will be described. Currently, the civil–military medical collaboration is getting closer and becoming interdependent, from research and development for the prevention of infectious diseases to disasters and emergencies management, as recently demonstrated in Ebola and Zika outbreaks and the COVID-19 pandemic, even with the high biocontainment aeromedical evacuation, in a sort of global health diplomacy.
... Historically, the principal method to control insect vectors of human and animal disease is chemical insecticides (Kitchen, et al., 2009). However, most of these products present risks to human health and the environment, as well as, the selection of phenotypically resistant insects (Rivero et al., 2010;Himeidan et al., 2012). ...
Insect vectors of Leishmaniases, Chagas disease and African trypanosomiasis remain human health, veterinary and economic problems worldwide. Several sex pheromones molecules that contribute to mating behavior have been identified in these vectors. These chemical signals are potential alternatives to traditional chemical insecticides. This review discusses the diversity of sex pheromone molecules and their role in the mating behavior of insect vectors of Leishmaniases, Chagas disease and African trypanosomiasis. The selection of studies was made based on research and review articles that presented sex pheromone aspects regarding insect vectors. In some species, these molecules have a dual function as serving as sex and aggregation pheromone. We also highlight the current knowledge of these substances as potential vector control tools. The studies revealed that sex pheromones applicability is largely experimental and restricted to some vectors. Based on these limitations, we included updated tables with the chemical identity of several sex pheromone compounds and other relevant information concerning the target species, which can contribute to future studies of control methodologies.
... For human and animal use it is mostly applied as a spray or lotion directly on the skin to avoid mosquito bites. Studies have also reported the incorporation of DEET in clothes and nets (Kitchen et al., 2009;Pennetier et al., 2010;Sibanda et al., 2018;Di Lorenzo et al., 2019). However, an explorative online search for treated textile products available in Switzerland revealed that manufacturers rarely impregnate textiles with DEET, likely since DEET can damage some synthetic fabrics (Brown & Hebert, 1997). ...
The biocide diethyltoluamide (DEET) is used worldwide as an insect repellent on human and animal skin and is among the most frequently detected organic chemicals in surface waters. The ubiquitous detection of DEET in Swiss waters, even during winter months, despite its apparent seasonal use as an insect repellent, has led to question the sources and fate of DEET in the environment and the validity of previous risk assessments for Switzerland. This study summarizes the occurrence, fate and emission dynamic of DEET in Swiss aquatic systems and attempts to clarify its sources in the Swiss aquatic environment. Existing monitoring data for DEET in the aquatic environment and WWTPs were collected from Swiss institutions, cantonal and federal authorities and aggregated to estimate the consumption of DEET in Switzerland. In addition, the main actors of DEET's supply chain in Switzerland (manufacturers, formulators and distributors) were surveyed to determine the production and distribution volumes of DEET-containing products. The findings from both approaches were then compared to provide a first mass balance for DEET in Switzerland. Analysis of Swiss monitoring data, particularly from the Rhine River, indicates an annual Swiss consumption of 2 tons of DEET, which is consistent with the estimate of 2 to 12 tons of DEET estimated from production data provided by the DEET supply chain. These values provide a first indicative mass balance for DEET in Switzerland and demonstrate that, from a mass balance perspective, the widespread detection of DEET in Swiss waters can be corroborated by its consumption as an insect repellent alone. Although DEET is classified as an inherently biodegradable substance, the evaluation and aggregation of Swiss monitoring data indicates that its degradation in Swiss surface waters is not as high as expected from literature. The Biocidal Products Regulation (BPR, (EU) 528/2012) regulates the authorisation of biocidal products in the European Union. In Switzerland the authorisation of biocidal products is regulated by the Ordinance on Biocidal Products (OBP,RS 813.12) and a Mutual Recognition Agreement with the European Union (MRA, RS 0.946.526.81) ensuring the agreed technical equivalence with the BPR. The authorization is based on established models for environmental risk assessments: the emission scenario documents (ESD). The ESD pertinent to DEET (Product Type 19-Repellents and attractants, ECHA, ESD PT19) were evaluated in this study and compared to the aggregated monitoring data and newly obtained mass balance of DEET for Switzerland. The ESD-based environmental risk assessment significantly overestimates the release and occurrence of DEET in Swiss surface waters and provides a worst-case scenario that is consistent with the precautionary principle. In summary, this study provides a characterization of DEET occurrence in Swiss waters as well as DEET Swiss consumption to extrapolate a first indicative mass balance of DEET for Switzerland and compare this to established models for environmental risk assessment. This approach could be exemplary for other biocidal products whose emissions and occurrence are unclear and which are characterized by higher ecotoxicity than DEET.
... People who live or temporarily stay away from permanent housing can be exposed to malaria vectors outdoors [1]. These people include military personnel on active duty [2,3], residents and workers in the forests of South America [4] and Southeast Asia [5], migrants [6,7] and displaced populations [8]. In addition to longlasting insecticide-treated nets (LLINs) and indoor residual spraying (IRS), measures used to tackle vectorborne disease in these special populations include chemoprophylaxis, mass drug administration (MDA) [9] and mosquito bite prevention [10]. ...
Background
While there is strong evidence that bite protection methods such as permethrin-treated clothing and topical insect repellents are protective against insect bites, there are few studies assessing the impact on malaria infection. This study will estimate the protective efficacy of treated uniforms and DEET insect repellent on the incidence of malaria infection among military personnel in an operational setting. Permethrin-treated uniforms used with DEET lotion will be compared to etofenprox-treated uniforms with DEET lotion. The effect of DEET lotion will be estimated by comparing permethrin-treated uniforms with DEET or placebo lotion.
Method
A cluster randomised double-blind placebo-controlled trial is planned to evaluate the effectiveness of the interventions on preventing malaria infections in soldiers on active duty at Mgambo National Service Camp in Tanga, Tanzania. The arms are (1) permethrin-treated uniform with 30% DEET liposome formula; (2) permethrin-treated uniform with placebo lotion; (3) candidate insect repellent system, i.e. etofenprox-treated uniform with 30% DEET liposome formula; and (4) placebo, i.e. untreated uniforms with placebo lotion. The primary outcome is the incidence of Plasmodium falciparum malaria infection detected by polymerase chain reaction (PCR) by active case detection using surveys every 2 weeks for 12 months. Rapid diagnostic tests will be used for the diagnosis of participants with symptoms.
The unit of randomisation will be combania: companies formed by recruits aged 18 to 25 years; combania do activities together and sleep in the same dormitory. Unequal randomisation will be used to optimise statistical power for the primary comparison between permethrin-treated uniforms with DEET and etofenprox-treated uniforms with DEET.
Discussion
This trial will provide the estimate of the effects of permethrin with DEET compared to those of the new fabric treatment etofenprox with DEET and any additional effect of using DEET. The results will inform strategies to protect military personnel and civilians who have more outdoor or occupational malaria exposure than the general public.
Trial registration
ClinicalTrials.gov NCT02938975 .
... Pyrethrum is a natural oil derived from the flowers of the plant Chrysanthemum cinerariifolium [15]. Among the synthetic analogs of pyrethrum, the permethrin, first synthesized in the United States in 1972 [22] and initially registered for agricultural use in 1979, became a cornerstone for the prevention and control of important VBDs in a few years' time. The use of this molecule in different formulations is effective in controlling the vectors of malaria [2], as well as useful against the sand fly vectors of Leishmania [3,23,24]. ...
Leishmaniosis is a vector-borne disease transmitted to animals and humans by the bite of blood-sucking phlebotomine sand flies. These small insects play a crucial role in the diffusion of the disease. To date, the sole strategy recognized for the prevention of leishmaniosis is the use of topical repellent compounds against sand fly bites. Several synthetic insecticides and repellents have been developed; however, the wide and unprejudiced use of these formulations have led to the loss of their effectiveness and the development of resistance phenomena. Moreover, some of these synthetic repellents have severe detrimental effects on the environment and could represent a serious threat to both animal and human health. Recently, an increased interest in the research on alternative approaches to sand fly control has been expressed. In this study, we systematically reviewed the efforts of the scientific community to individuate a phytochemical alternative for the control of sand fly species recognized as vectors of Leishmania spp. Based on literature research using different electronic databases, a total of 527 potentially relevant studies were screened and narrowed down to a final 14 eligible scientific reports. Our analysis suggests that although there is a rapidly growing body of literature dedicated to botanical insecticides and repellents against sand fly vectors of Leishmania spp., much of this literature is limited to in vitro studies conducted in laboratory conditions, and only a few of them investigated the repellency of plant-based products. These studies highlighted that natural compounds display a really short period of action and this significantly limits the use of these products as an alternative to chemical-based repellents.
... These people include military personnel on active duty [3,4], residents and workers in the forests of South America [5] and southeast Asia [6], migrants [7,8] and displaced populations [9]. In addition to longlasting insecticide-treated nets (LLINs) and indoor residual spraying (IRS), measures used to tackle vector-borne disease in these special populations include chemoprophylaxis, mass drug administration (MDA) [10] and mosquito bite prevention [11]. ...
Background: While there is strong evidence that permethrin-treated clothing and topical insect repellents are protective against insect bites, there are few studies assessing the impact on malaria infection. This study will evaluate the impact of the protective efficacy of bite prevention methods on the incidence of malaria infection among military personnel in an operational setting. Permethrin-treated uniforms will be compared to etofenprox-treated uniforms, with both clothing treatments used in conjunction with DEET insect repellent. An additional study arm will test permethrin uniforms with placebo lotion to determine if there is any additional protective effect of using DEET with insecticide-treated clothing.
Method: A cluster randomised double-blind placebo-controlled trial is planned to evaluate the effectiveness of the interventions on preventing malaria infections in soldiers on active duty at Mgambo National Service Camp in Tanga, Tanzania. The arms are (1) permethrin-treated uniform with 30% DEET liposome formula; (2) permethrin-treated uniform with placebo lotion; (3) candidate insect repellent system, i.e., etofenprox-treated uniform with 30% DEET liposome formula; and (4) placebo, i.e., untreated uniforms with placebo lotion. The primary outcome is the incidence of Plasmodium falciparum malaria infection detected by polymerase chain reaction (PCR) by active case detection using surveys every 2 weeks for 12 months. Rapid diagnostic tests will be used for diagnosis of participants with symptoms.
The unit of randomisation will be combania: companies formed by recruits aged 18 to 25 years; combania do activities together and sleep in the same dormitory. Unequal randomisation will be used to optimise statistical power for the primary comparison between permethrin-treated uniforms with DEET and etofenprox-treated uniforms with DEET.
Discussion: This trial will estimate the effects of permethrin with DEET compared to those of the new fabric treatment etofenprox with DEET and any additional effect of using DEET. The results will inform strategies to protect military personnel and civilians who have more outdoor or occupational malaria exposure than the general public.
Trial registration: clinicaltrials.gov Registration number NCT02938975.
... Six individual chemicals in the pyrethrum extract have active insecticidal properties, called pyrethrins. 3 Pyrethroid structure modification (synthetic pyrethroid) in 1973 led to development of permethrin, which had improved potency and stability in air and sunlight for use in agriculture. 4 The U.S. military has relied on permethrin as an active ingredient in clothing repellent since the 1990s. 5 Globally, pyrethroid use in vector control dominates other insecticide classes in total surface area treated and has increased from 60% in year 2000 to 83% in 2009. ...
Introduction
Permethrin is a common pesticide spray-applied to civilian clothing and military uniforms for protection against biting arthropods in an effort to reduce risks to arthropod-borne diseases. During mass clothing spray events, exposure is possible through the dermal, inhalation, and ingestion routes. The potentially exposed population during a spray event includes the pesticide applicator(s) and working party (personnel who handle clothing/uniforms by positioning on the ground, flipping, and removing after spraying is complete). Previous investigation is limited regarding permethrin exposure via multiple routes of entry. Additionally, most exposure assessments are limited to pesticide applicators rather than working party that support applicator personnel. The purpose of this investigation was to conduct a multi-route exposure assessment for all personnel normally participating in mass permethrin military uniform treatments.
Materials and Methods
The protocol and Informed Consent Document were approved by the Uniformed Services University of the Health Sciences (USUHS) Institutional Review Board (IRB) before fieldwork initiation (IRB number: USUHS.2019-032). Sampling occurred during routine spray events performed by 14 U.S. Navy personnel (3 applicators and 11 working party) over 2 days. Personal exposures were measured with dermal sampling, and airborne concentrations were measured with area air sampling. Permethrin area air sampling and analysis were conducted using OSHA Versatile Sampler-2 sampling media (n = 36). Dermal exposure was measured using dosimeter gloves (n = 26) and a dermal patch (n = 26) worn by study participants.
Results
All air samples were reported below the 0.4 µg limit of quantification. Glove sample results ranged from 45 to 120,000 µg and patch results ranged from 0.57 to 45 µg. A repeated-measures ANOVA showed non-statistically significant differences in dermal concentrations (P-value = .8340) between the applicators and working party in patches and gloves.
Conclusions
Results suggest dermal contact is the primary route of exposure compared to inhalation when mass spraying clothing with permethrin. Similar dermal exposures between these two occupations may necessitate reconsidering risk assessment procedures, training and personal protective equipment (PPE) requirements for mass spray uniform treatments. Specifically, while PPE requirements for applicators are highly regulated by the Armed Forces Pest Management Board and include items such as Tyvek suits, chemical protective gloves, and air-purifying respirators, PPE was not regulated for working party personnel before this investigation.
... The identification of these pollutants in surface waters is not uncommon. 47−49 For example, DEET is the primary ingredient used in insect repellents 50 and an abundant and frequently detected pollutant in surface waters. 51−53 DEET was detected in three surface water samples (S1−S3, see Table S3) and was most prominent in the industrial and wastewater effluent samples collected in Sri Lanka, representing >12% of the total sample abundance. ...
The life-critical matrices of air and water are among the most complex chemical mixtures that are ever encountered. Ultrahigh-resolution mass spectrometers, such as the Orbitrap, provide unprecedented analytical capabilities to probe the molecular composition of such matrices, but the extraction of non-targeted chemical information is impractical to perform via manual data processing. Automated non-targeted tools rapidly extract the chemical information of all detected compounds within a sample dataset. However, these methods have not been exploited in the environmental sciences. Here, we provide an automated and (for the first time) rigorously tested methodology for the non-targeted compositional analysis of environmental matrices using coupled liquid chromatography–mass spectrometric data. First, the robustness and reproducibility was tested using authentic standards, evaluating performance as a function of concentration, ionization potential, and sample complexity. The method was then used for the compositional analysis of particulate matter and surface waters collected from worldwide locations. The method detected >9600 compounds in the individual environmental samples, arising from critical pollutant sources, including carcinogenic industrial chemicals, pesticides, and pharmaceuticals among others. This methodology offers considerable advances in the environmental sciences, providing a more complete assessment of sample compositions while significantly increasing throughput.
... Insect repellents have long been used for preventing bites from blood-sucking arthropods (see review by Moore and Debboun 2006). DEET (N,N-diethylm-toluamide) is the most successful arthropod repellent in about six decades and has been the mostly widely used active ingredient in topical repellents to protect humans and livestock against variety of arthropods including mosquitoes , Fradin 1998, Qiu et al. 1998, SchoÞeld et al. 2007, Syed and Leal 2008, biting midges (Harlan et al. 1983, Magnon et al. 1991, Young and Evans 1998, tabanids (Catts 1968), sand ßies (Schreck et al. 1982, Coleman et al. 1993, YaghoobiÐErshadi et al. 2006, black ßies (Robert et al. 1992, Kalyanasundaram and Mathew 2006, Tawatsin et al. 2006, horse ßies (Blume et al. 1971), chiggers (Lerdthusnee et al. 2003, Kitchen et al. 2009), ticks (Carroll et al. 2005, Zhang et al. 2009), and leeches (Kochhlar et al. 1974, Kumar et al. 1984, Tawatsin et al. 2006, Frances 2006a). The concentration of DEET used in a multitude of formulations around the world varies from 5 to 100% (Young and Evans 1998). ...
In recent years, the common bed bug, Cimex lectularius L. (Hemiptera: Cimicidae), became a major public health concern in urban communities. Bed bugs are notoriously difÞcult to control, and their bites are not tolerated by most people. The public has an urgent need for materials and methods to reduce bed bug introduction and bites during work, travel, or sleep. A repellent product will help achieve these goals by discouraging and preventing bed bugs from moving to a protected area. We evaluated the repellency of three commercially available insect repellent or control materials and Þve nonregistered materials with the goal of identifying safe and effective bed bug repellents. The two commercial repellent products that contained 7% picaridin or 0.5% permethrin had little repellency against bed bugs. N,N-diethyl-m-toluamide (DEET), the most commonly used insect repellent, provided a high level of repellency against bed bugs. When a host cue (carbon dioxide) was present, the minimum DEET concentration to repel Ն94% of the bed bugs for a 9-h period was 10%. The longevity of repellency of DEET was concentration dependent. At 25% concentration, DEET-treated fabric surface remained highly repellent to bed bugs for a 14-d period. However, DEET has a strong smell and dissolves certain plastic materials. Therefore, we evaluated several odorless, noncorrosive, and potentially effective repellents. Isolongifolenone and isolongifolanone, two natural products and recently reported insect repellents, exhibited strong repellent property against bed bugs but at signiÞcantly lower levels than DEET. Three novel potential repellent compounds discovered by Bedoukian Research Inc. (Danbury, CT) exhibited similar level of repellency and longevity as DEET for repelling bed bugs. These nonirritant and odorless compounds are promising candidates as alternatives to DEET for reducing the spread of bed bugs and bed bug bites.
... Control and treatment of vector-borne diseases by vaccines and drugs faced numerous restrictions. So, over the past few decades, personal protection measures against mosquitoes and other medically important arthropods have played a significant role in integrated vector management (IVM) programs [1][2][3][4][5][6]7] . Personal protection technologies such as insecticidetreated clothes and nets are one of the most effective tools against mosquitoes. ...
Permethrin-impregnated cloths and uniforms are one of the most effective personal protection measures against a variety of vector arthropods. Today, the dipping method with commercially available permethrin emulsions is a common method to impregnation of fabrics. But these formulations suffered from low durability on fabrics. In this regard, technical permethrin was formulated to permethrin solution (Emulsion), polymeric and microencapsulated formulations and their residual persistency was measured chromatographically on military uniform fabrics. Additionally, impregnated-fabrics efficacy on the knockdown and mortality were evaluated against Anopheles stephensi L. (Diptera: Culicidae). The obtained results showed markedly higher residual permethrin quantities with the polymeric and microencapsulated formulation, resulting in 237 and 124 mg/m 2 still present after 50 defined launderings, respectively. The knockdown and mortality rates of A. stephensi after 10 and 20 launderings, respectively, were significantly higher (P<0.05) for mosquitoes exposed to the polymeric and microcapsule formulations. The evaluation of the laundering-dependent time frame for obtaining 100% knockdown of mosquitoes constantly exposed to permethrin-impregnated fabrics indicated that 100% knockdown time of A. stephensi ranging from 3.5 min, 4.2 min and 4.1 min, prior to laundering, respectively. After 50 launderings, 100% knockdown time was > 120 min, 28.6 min and 45.8 min, for permethrin solution, polymeric and microcapsule formulations, respectively. These findings confirm the incremental impact of polymeric and microcapsule formulations on permethrin persistency and residual activity on fabrics against A. stephensi.
... Arthropod-borne diseases such as malaria or leishmaniasis transmitted to humans from the bites of infected mosquitoes or sand flies, respectively, continue to pose significant threat to United States (US) military personnel worldwide (Kitchen et al. 2009;Stoops et al. 2013;Garcia et al. 2017). Lacking effective or approved vaccines for these and other high-risk arthropod-borne pathogens such as Zika, chikungunya, or dengue viruses the best strategy for reducing disease risk is to reduce contact between humans and arthropod vectors (Scott and Morrison 2004;Eisen et al. 2009;World Health Organization 2014). ...
The prevention of vector-borne disease to protect the health and readiness of United States forces in the field continues to be a high priority for the US Department of Defense. Previous studies have demonstrated that the risk of human contact with disease-vector mosquitoes and other biting flies can be reduced by applying an insecticide to perimeters of military materials such as camouflage netting or HESCO blast protection wall geotextile already in place around troops in the field. In this study we investigated whether residual pesticide efficacy will persist in the presence of earth fill that is required for operational use of HESCOs, using a warm temperate field site in north Florida. Results from laboratory bioassays measuring mosquito mortality and field collections of natural mosquito populations indicated superior efficacy and greater longevity of pesticide treated geotextile exposed to soil fill. These findings not only support immediate implementation of this technique in US military field scenarios, but also provide evidence that HESCO technology currently used in natural disaster flood control could be leveraged to protect civilian personnel from emerging floodwater mosquitoes.
... Historically, disease nonbattle injuries (DNBI) have caused more casualties than combat, and DNBI caused by arthropod vectors have impacted almost every major military operation (Pages et al. 2010). Notable examples are yellow fever during the Spanish-American War and malaria in the Pacific Theater during World War II (Kitchen et al. 2008). For this reason, the Army, Navy, and Air Force commission officers with advanced degrees in entomology and maintain mission-specific preventive medicine units. ...
The United States Department of Defense (DoD) employs advanced-degreed entomologists as Preventive Medicine and Public Health Officers in the Army, Navy, and Air Force. While the primary objective of military entomologists is service member health and readiness (“force health protection”), military entomology resources can provide support to civil authorities as directed by the President or Secretary of Defense through Department of Defense Directive 3025.18, Defense Support of Civil Authorities (DSCA). The employment of DSCA is complex and involves the consideration of such factors as the proper request process, funding, legality, risk, appropriateness, and readiness. Once approved and mobilized, however, military preventive medicine assets can be of significant help to civil authorities when dealing with emergency vector control. This paper will address some of the policy issues surrounding the use of DSCA, outline the resources available from the individual military services, and provide examples of DoD contingency vector control support to civil authorities.
... Arthropod-borne diseases such as malaria or leishmaniasis transmitted to humans from the bites of infected mosquitoes or sand flies, respectively, continue to pose significant threat to United States (US) military personnel worldwide (Kitchen et al. 2009;Stoops et al. 2013;Garcia et al. 2017). Lacking effective or approved vaccines for these and other high-risk arthropod-borne pathogens such as Zika, chikungunya, or dengue viruses the best strategy for reducing disease risk is to reduce contact between humans and arthropod vectors (Scott and Morrison 2004;Eisen et al. 2009;World Health Organization 2014). ...
The JFMCA (Journal of the Florida Mosquito Control Association) Vol 67, 2020 published 7 research articles, 7 scientific and operation notes, and submitted abstracts of the 91st annual meeting of the FMCA. The Journal has been published once a year.
... We have demonstrated the efficacy of residual pesticide treatment of US military materials such as camouflage netting and HESCO blast wall geotextile material to reduce biting pressure from a range of natural populations of disease-vector and nuisance insects across multiple field environments (Britch et al. 2010(Britch et al. , 2011. This method of passive control may be leveraged as a key component of the Department of Defense integrated vector management (IVM) system (Kitchen et al. 2009) to protect personnel within perimeters of treated materials in the field. Although the initial residual pesticide treatment may be applied as a factory treatment or by units prior to deployment, the efficacy of the treatment will eventually wane and require retreatment in the field. ...
Residual pesticide treatment of US military materials such as camouflage netting and HESCO blast wall geotextile is an effective way to reduce biting pressure within protected perimeters. However, residual treatments eventually wane and require retreatment in situ, which may not be possible or practical in military scenarios. One solution is to install pesticide misting systems on treated perimeters, which may additively enhance residual treatments, and gradually retreat perimeter material as misted pesticide settles. In this investigation we show that pesticide misting can extend efficacy of residual treatments on HESCO geotextile against mosquitoes and sand flies in a hot-arid desert environment by 1–2 wk.
... The first residual insecticide DDT was added to the vector control toolbox in the early 1940s, consequently increasing the popularity of insecticide-based control. World War II had stemmed the supply of pyrethrum (derived from chrysanthemum flowers) from Japan, and alternatives were urgently needed [90]. The first major demonstration of DDT use was at the end of World War II when the allies used the insecticide to control an epidemic of typhus, transmitted by body lice, amongst the populations of war-torn Europe [91]. ...
Vector-borne diseases (VBDs) such as malaria, dengue, and leishmaniasis exert a huge burden of morbidity and mortality worldwide, particularly affecting the poorest of the poor. The principal method by which these diseases are controlled is through vector control, which has a long and distinguished history. Vector control, to a greater extent than drugs or vaccines, has been responsible for shrinking the map of many VBDs. Here, we describe the history of vector control programmes worldwide from the late 1800s to date. Pre 1940, vector control relied on a thorough understanding of vector ecology and epidemiology, and implementation of environmental management tailored to the ecology and behaviour of local vector species. This complex understanding was replaced by a simplified dependency on a handful of insecticide-based tools, particularly for malaria control, without an adequate understanding of entomology and epidemiology and without proper monitoring and evaluation. With the rising threat from insecticide-resistant vectors, global environmental change, and the need to incorporate more vector control interventions to eliminate these diseases, we advocate for continued investment in evidence-based vector control. There is a need to return to vector control approaches based on a thorough knowledge of the determinants of pathogen transmission, which utilise a range of insecticide and non–insecticide-based approaches in a locally tailored manner for more effective and sustainable vector control.
... N, N-diethyl-m-toluamide (DEET, diethyltoluamide) is one of the most detected trace organic contaminants (TOrC) in environmental water samples Bussan et al., 2017;Kolpin et al., 2002;Loraine and Pettigrove, 2006). DEET is primarily used an insect repellent and was developed by the US army in 1946 and made available to the general public in 1957 (Kitchen et al., 2009). Currently, DEET as the active ingredient for insect repellents can be found in many different formulations such as spray, liquid and lotion in concentrations as high as 100% or incorporated into consumer products like clothes (Pennetier et al., 2010). ...
DEET (N, N-diethyl-m-toluamide) is one of the most frequently detected trace organic contaminants (TOrC) in wastewaters and is used primarily as an insect repellent. It was introduced for use in the general public in 1957. It is ubiquitously present in the environment and DEET concentrations are usually among the highest reported for TOrCs. Due to recent concerns about possible analytical interferences in detection methods being reported, this study focused on possible artifacts caused by seasonal, spatial, and diurnal variations in wastewater influent concentration of DEET. We also compared usage data to observed wastewater concentrations of seven wastewater treatment plants (WWTPs) in four different regions in the US monitored from November 2014 to November 2016. Consumption data obtained reveal patterns of consumption according to climatic regions and season. During the summer DEET usage accounts for almost 60% of all usage during a year, while during the winter months DEET usage accounts for <5%. Concerning spatial distribution, while per capita consumption of DEET in Florida is three times higher than the one observed in Arizona (44 g vs 14 g), DEET concentrations in wastewater tend to be much higher in Arizona. Regardless of WWTPs or monitoring period, concentrations as high as 15,200 ng/L were observed during the month of October 2016. While DEET has a diurnal variation in the wastewater influent, with a maximum at 18:00, the diurnal variability is not enough to explain the great discrepancies between consumption of DEET versus occurrence in wastewaters. Although LC-MS/MS analysis of isobaric and structural mimics suggests some possibility of interferences, NMR spectroscopy analysis of environmental samples does not support the presence of such mimics in real samples.
... In such scenarios, treated clothing or blankets could reduce infectious disease burden on displaced and vulnerable populations [11,12]. Fabric treatment with the insecticide permethrin has a long history and has been practised by the armed forces of many countries including the USA, Australia, Germany and France [13][14][15][16]. Insecticidal fabrics are now commercially available for civilian use as well [17] and various studies over the years have shown the bioefficacy of these fabrics against mosquitoes and other biting arthropods [18,19]. ...
Background:
Insecticidal fabrics are important personal protective measures against mosquitoes, ticks and other disease vectors. In the absence of internationally accepted guidelines, bioefficacy tests have been carried out using continuous exposure and three minutes exposure bioassay methods. Recently, we have reported an improved method for bioefficacy testing of insecticidal fabrics, which involves continuous exposure of mosquitoes to the test fabrics. The present paper reports the comparative evaluation of the outcomes of the continuous exposure bioassay and the three minutes bioassay on the same fabric samples.
Methods:
Permethrin content in the treated fabric samples was determined through HPLC analysis and NMR studies were performed to establish the stability of the analyte. Bioefficacy tests were carried out against dengue vector Aedes aegypti and malaria vector Anopheles stephensi as per the improved test method and the three minutes bioassay method.
Results:
The permethrin doses in the fabric samples ranged from 60 to 3000 mg/m2 and 36.2% of permethrin was retained after 10 washings. The extraction and chromatographic analysis were not found to affect the stability of permethrin. In continuous exposure, all fabric samples showed bioefficacy, as the mean complete knockdown time for both Ae. aegypti (10.5-34.5 min) and An. stephensi (14.5-36.8 min) was ≤ 71.5 min. The same samples were found to be not effective when tested using the three minutes bioassay method, since the knockdown and mortality percentages were well below the required bioefficacy values. The bioefficacy of the fabric samples in terms of complete knockdown time was significantly higher against Ae. aegypti in comparison to An. stephensi. The mean complete knockdown time of Ae. aegypti increased to 48.3 min after 10 washings indicating a significant reduction in bioefficacy.
Conclusions:
Bioefficacy testing of the insecticidal fabrics using the improved method resulted in outcomes, which could be correlated better with the permethrin content in the fabric samples. The improved method is more appropriate for the testing of insecticidal fabrics than the three minutes bioassay method. Further evaluation of the improved method using different test arthropods could help in the formulation of specific guidelines for the bioefficacy testing of insecticidal fabrics.
... Insect repellents developed by government and private industries are very effective at deterring mosquitoes and protecting the users from contracting these diseases 14 . DEET (N,N-Diethyl-3-methylbenzamide) has been the benchmark of insect repellents since its development for the United States Army to use in tropical regions where there is a high incidence of insect transmitted diseases 15 . ...
There is an increased need for improved and affordable insect repellents to reduce transmission of rapidly spreading diseases with high mortality rates. Natural products are often used when DEET cannot be afforded or accessed and when consumers choose not to use a synthetic repellent. The essential oils from two newly bred Nepeta cataria (catnip) plants representing two different chemotypes and their respective isolated nepetalactone isomers were evaluated as mosquito repellents against Aedes aegypti mosquitoes that transmit the Zika and Dengue virus in a one choice landing rate inhibition assay. A dose response curve was generated for each treatment and a time course analysis of repellency was performed over 24 hours with a N. cataria essential oil sample. The results indicate that all essential oil samples and their respective purified nepetalactone isomers were able to achieve greater than 95% repellency. Between two and four hours, the ability to repel more than 95% of the mosquitoes diminished. At the lowest concentrations tested, the nepetalactones and crude essential oil samples were more effective than DEET at reducing the number of mosquito landings.
... These fine mesh nets are usually formulated with a pyrethroid insecticide such as permethrin or deltamethrin, and can be effective for up to a year or even longer (Rozendaal 1997, Martin et al. 2007). Since the mid-1990s, LLINs have been employed in tropical and subtropical regions of the world to control mosquitoes and reduce the spread of malaria (Alonso et al. 1991, Lengeler 2004, Kitchen et al. 2009) and to kill vectors of other arthropod-borne diseases (Dutta et al. 2011). This strategy has also been used to protect livestock against arthropodborne diseases, such as suppressing the abundance of the bluetongue virus vector Culicoides imicola Kieffer (Diptera: Ceratopogonidae) among cattle in sheds (Calvete et al. 2010). ...
Stored products represent an enormous economic output, but insects regularly immigrate into stored products from the surrounding landscape throughout the postharvest supply chain. Long-lasting insecticide-incorporatednetting (LLIN), which usually contains an incorporated pyrethroid, has been used as part of a strategy to reduce the spread of malaria in tropical regions since the 1990s and has only recently been considered for its application in pre-and postharvest agricultural contexts. The goal of this study was to determine how short-term exposure to LLINs in the laboratory impacts the locomotory behavior and mortality for adult Tribolium castaneum (Herbst), (Coleoptera: Tenebrionidae) red flour beetle, and Rhyzopertha dominica (Fauvel), (Coleoptera: Bostrichidae) lesser grain borer, at different periods of time after exposure. Exposure to LLINs resulted in multiple-fold reductions in the distance moved and elevated angular velocity in both species that quickly took effect and persisted even after 168 h compared with adults exposed to control netting. R. dominica was somewhat more susceptible than T. castaneum to LLINs. Finally, the dispersal capacity of both species, measured as ability to move to a remote resource patch, was significantly impaired or absent after exposure to LLINs compared to adults exposed to control netting. Our results demonstrate that LLINs are a promising new technology for reducing infestation by stored product insects since even short exposures limit movement and ultimately lead to knockdown and death.
... 21 Being the most widely tested and used compound, it is considered the gold standard insect repellent by the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC) for protection against malaria, and is the standard by which other insect repellents are compared. [22][23][24] It is also recommended by other health authorities, including CHP (HKSAR), Environmental Working Group (EWG) (USA), Advisory Committee for Malaria Prevention in Travellers (ACMP) and National Health Service (NHS) (UK), Australian Pesticides and Veterinary Medicines Authority (APVMA) (Australia) and Pest Management Regulatory Agency (PMRA) of Health Canada. 7,11,15,16,18,19 Interestingly, many natural repellents products specifically write down they do not contain DEET on their packaging according to our market survey. ...
Mosquito-borne diseases are global problems. The use of topical insect repellents is a key measure recommended by health authorities to prevent mosquito-borne diseases. Despite more than a hundred commercial products available in the market, there are relatively few active ingredients used across these formulations. The most common active components are diethyltoluamide, picaridin, p-menthane-3,8-diol, ethyl butylacetylaminopropionate (IR3535) and a range of plant-derived products. Research has shown that each of these active ingredients vary in the duration of protection provided against biting mosquitoes. However, the wide spectrum of commercial preparations and various recommendations from different health authorities make it a challenge to pick an effective product for end users as well as healthcare personnel. A local market survey was conducted to assess the mosquito repellent formulae in available products in Hong Kong, and a review of the current recommendations issued by local and overseas authorities on choosing the suitable insect repellents is performed with consideration of recent research and currently available topical repellents in the market.
... The ethyl acetate extract of the culture filtrate of the phytopathogenic fungus Diaporthe eres was investigated as part of ongoing research, supported by the Deployed War Fighter Protection (DWFP) program of the Department of Defense, to discover environmentally benign mosquito control agents (Kitchen et al. 2009). Using the active naturally occurring metabolite as the basis, several analogs were synthesized and then evaluated against permethrin-susceptible and permethrin-resistant adult and larval Ae. ...
The culture filtrate of a plant pathogenic fungus that infects English ivy (Hedera helix L., Araliaceae) was investigated for mosquitocidal constituents by bioassay-guided isolation. The fungus responsible for pathogenic effects on the plant H. helix has been identified as Diaporthe eres Nitschke by molecular techniques. The mosquito adulticidal constituent in the culture filtrate was identified as 3,4-dihydro-8-hydroxy-3,5-dimethylisocoumarin (1) by spectroscopic techniques. Laboratory bioassays showed that (1) had larvicidal activity against permethrin-susceptible and -resistant Aedes aegypti strains. This compound was not active as an adulticide when tested by topical bioassay. Several analogs of (1) were synthesized and had better mosquitocidal activities than the naturally occurring (1) constituent.
... Research performed on the use of bed nets among minority groups indicated that human, socioeconomic, and environmental factors can all affect the use of bed nets in China [5,7] and Solomon Islands [6]. Bed net use became compulsory for US soldiers in the Pacific during World War II following severe outbreaks of malaria and dengue fever [21,22]. International health groups are providing long-lasting, insecticide-treated nets to residents in malaria endemic areas of underdeveloped countries, particularly in Africa. ...
Background
: In China, mosquito-borne diseases are most common in the sub-tropical area of Yunnan province. The objective of this study was to examine behaviors related to mosquito-borne diseases in different ethnic minority groups and different socioeconomic groups of people living in this region.Methods: A stratified two-stage cluster sampling technique with probability proportional to size was used in Mengla County, Xishuangbanna Prefecture, Yunnan. Twelve villages were used to recruit adult (≥18 years old) and eight schools were used for children (<18 years old). A questionnaire on behaviors and environment variables related to mosquito-borne diseases was devised.Results: Multiple correspondence analysis (MCA) grouped 20 behaviors into three domains, namely, environmental condition, bed net use behaviors, and repellent use behaviors, respectively. The Han ethnicity had the lowest odds of rearing pigs, their odds being significantly lower than those of Yi and Yao. For bed net use, Dai and other ethnic minority groups were less likely to use bed nets compared to Yi and Yao. The odds of repellent use in the Han ethnicity was lower than in Yi, but higher than in Dai. The Dai group was the most likely ethnicity to use repellents. Farmers were at a higher risk for pig rearing and not using repellents. Education of less than primary school held the lowest odds of pig rearing. Those with low income were at a higher risk for not using bed nets and repellent except in pig rearing. Those with a small family size were at a lower risk for pig rearing.Conclusion: Different ethnic and socioeconomic groups in the study areas require different specific emphases for the prevention of mosquito-borne diseases.
... In forested areas away from human habitation, the reservoir hosts are wild animals, and prevention of sand fly bites is even more difficult. Preventive measures may include protection from sand fly bites, for instance, by avoiding nocturnal outdoor activities as much as possible, wearing protective clothing, and applying insect repellent to exposed skin, and insecticidal sprays in residences [148,149]. The use of bed nets impregnated with longlasting insecticides may also be helpful [150]. ...
The parasitic disease leishmaniasis is caused by protozoa of the genus Leishmania which are transmitted by sand fly vectors of the genus Phlebotomus in the Old World and Lutzomyia in the New World. Transmission can either be anthroponotic (human to human) or zoonotic through mammalian reservoirs such as dogs and rodents. Leishmaniasis has three principal clinical manifestations, namely cutaneous leishmaniasis (CL), mucocutaneous leishmaniasis (MCL), and visceral leishmaniasis (VL). The cutaneous form characteristically causes skin ulcers, the mucocutaneous form manifests as lesions of skin, mouth, and nose, and the (potentially lethal) visceral form affects the internal organs such as spleen and liver and also invades the bone marrow. Leishmaniasis is endemic in about ninety-eight countries and the diverse types of the disease occur in different regions of the world. CL is most common in Afghanistan, Algeria, Pakistan, Iran, Brazil, and Colombia; MCL is mainly restricted to countries of the Amazon Basin; and VL is most frequently seen in the Indian sub-continent, the Horn of Africa (Sudan and Ethiopia), and Brazil. The current global prevalence is estimated at about 12 million, and each year, the disease in one of its forms makes about 2 million new victims and claims up to 50,000 fatalities. This paper presents epidemiological, biological, and clinical aspects of leishmaniasis throughout the world; then focuses on the disease in the Republic of Suriname (South America); addresses in more detail the species of Leishmania parasites in that country; and concludes with potential future directions to improve our understanding of leishmaniasis in Suriname.
... Mosquitoes have almost a worldwide distribution occurring in all continents except in Antarctica [1,2] . Their bite leads to allergic reactions, dermatitis and secondary infections [3] . They are vectors in transmission of malaria, filariasis, yellow fever, dengue, Japanese encephalitis, chikungunya, O'Nyong nyong, rift valley fever and west Nile virus [4] . ...
The present study determined phytochemical constituents and larvicidal activities of Tagetus minuta L., Adansonia digitata Linn., Ocimum suave, Plectranthus barbatus A., Azadirachta indica A. Juss., Lantana camara L. Phytochemical analysis established that saponins were present in all the plants. Alkaloids and flavonoids were present in 83% of all the extracts. Tannins and sterols were found in 67% of the plants. Terpenoids were present in 33% of the plants while glycosides were present in 16% of the plants. Larvicidal activity was tested on 4 th instar larva of Aedes aegypti. At the concentration of 1mg/ml, all the extracts exhibited 100% larval mortality except aqueous extract of L. camara that killed 90% of the larvae. In aqueous extracts, T. minuta extract was most active with LD50 of 0.61 and LD95 0f 2.256. Acetone extracts of T. minuta and hexane extract of was O. suave were most active as they caused 100% larval mortality at all tested concentrations thus LD50 and LD95 could not be determined for these extracts. These findings indicate that the selected plants have larvicidal activity. More studies are needed to evaluate the activities of the plants against other types of mosquito larvae and for possible development of larvicides that are safe to use and environment friendly.
Increased demand for recycling plastic has prompted concerns regarding potential introduction of hazardous chemicals into recycled goods. We present a broad screening of chemicals in 21 plastic flake and pellet samples from Canadian recycling companies. From target analysis, the organophosphorus ester flame retardants and plasticizers exhibited the highest detection frequencies (DFs) (5-100%) and concentrations (<DL-4,700 ng/g), followed by brominated/chlorinated flame retardants (<DL-2,150 ng/g, 5-76% DFs). The perfluoroalkyl acids were least detected at the lowest concentrations (<0.01-0.70 ng/g, 5-19% DFs). Using nontargeted analysis, 217 chemicals were identified as Level 1 (authentic standard) or 2 (library match), with estimated individual concentrations up to 1030 ng/g (highest: 2-hexyl hydroxy benzoate, 100% DF). Total (Σ60) element concentrations were between 0.005 and 2,980 mg/kg, with highest concentrations for calcium (2,980 mg/kg), sodium (617 mg/kg), and iron (156 mg/kg). Collectively >280 chemicals were detected in recycled plastic pellets and flakes, suggesting potential incorporation into recycled goods. Individual concentrations indicate unintentional trace contamination following European Union threshold limits for recycled granules (500 mg/kg) and waste plastic flakes (1,000 mg/kg), although do not reflect toxicological thresholds, if any. Our study highlights that while recycling addresses sustainability goals, additional screening of goods and products made from recycled plastics is needed to fully document potentially hazardous chemicals and exposure.
Pharmaceuticals and personal care products (PPCPs) are distinct group of chemicals, specifically referred to as emerging environmental contaminants because of their intrinsic capacity to trigger diverse physiological effects in humans. Numerous research investigations have confirmed the existence of PPCPs in diverse environmental matrices, which provokes worry about prospective severe implications to biodiversity and humans. For this reason, this manuscript reviews the present state-of-the-art information on PPCPs in aquatic environment. The environment risk associated with abundance of PPCPs was established based on occurrence, toxicity, and bioaccumulation. Existing information regarding the sources, migration, and degradation of these contaminants in the environment was provided. Subsequently, a comprehensive information concerning global PPCPs concentration in the aquatic environment was also provided. Carbamazepine appears to be the most persistent PPCPs judging from reports in literature based on different treatment strategies. A combined treatment strategy is recommended for improved removal efficiency of PPCPs in environmental media especially persistent PPCPs. A combination of microbial degradation with other treatment technologies will be the most effective for improved PPCPs eradication.
Background
Scrub typhus (ST) is one of the most underdiagnosed, potentially fatal febrile diseases in the Asia-Pacific region. We conducted a comprehensive review of the risk factors of ST over 19 years using data from a nationwide database.
Methods
We used data on ST from the nationwide database of the Taiwan Centers for Disease Control from 1996 to 2014 to analyse the incidence rates and relative risks of ST according to different regions. The trends of incidence rates over the study period were also evaluated. The distribution of confirmed ST cases was mapped using geographic information system software. The characteristics of confirmed ST cases and non-ST cases (cases with suspected ST but negative test findings) were compared.
Results
Among the 38,127 reported cases, there were 6,791 (17.8%) confirmed ST cases. The overall incidence rate of ST in Taiwan was 1.49 per 100,000 residents per year. The trend of incidence rates increased over time. The Island region had the highest incidence rate (56.55 per 100,000 residents per year), followed by the Eastern region (15.13 per 100,000 residents per year). More confirmed ST cases were distributed in mountainous areas of Taiwan Main Island and Island region. Compared to non-ST cases, individuals with confirmed ST were younger (median [interquartile range] age: 44 [26–57] years versus 45 [30–60] years, p < .001) and more likely to engage in at-risk occupations (29.4% versus 13.3%, p < .001), including farming and animal husbandry (16.6% versus 9.0%, p < .001) and the armed forces (12.3% versus 3.5%, p < .001); however, they had a lower rate of animal contact (12.8% versus 20.1%, p < .001).
Conclusions
ST is an endemic disease in Taiwan, particularly in the Island region, Eastern region and mountainous areas. Patients engaged in at-risk occupations and presenting with acute febrile diseases should undergo investigations for ST.
Today personal protection measures against mosquitoes and other medically important arthropods have a significant role in integrated vector management programs. Personal protection technologies such as insecticide-treated clothes and nets are some of the most effective tools against mosquitoes. Permethrin, as a synthetic pyrethroid insecticide, with features such as having a knockdown, repellency and residual activity, and low human and mammalian toxicity, is widely used for impregnation of fabrics and clothes. The dose required is 1250 mg/m 2 , which has not caused toxic effects in users. Many methods have been developed to impregnate fabrics and clothes with permethrin or similar compounds. However, new impregnation methods such as polymer-coating and microencapsulation technologies which may prolong the activity of insecticides on clothing are currently under development. These methods have the advantage of helping to overcome the inevitable reduction in efficacy over time that occurs as a result of washing, ultraviolet light exposure, and the normal wear and tear of the fabric. The aim of this review is to investigate the evidence base for the use of insecticide-treated clothing and military uniforms for protection against bites from arthropods and its effect on arthropod-borne pathogen transmission. Although insecticide-treated clothing can provide some protection against biting insects, few studies have shown complet protection (100%) in using insecticide-treated clothing alone, but most studies have mentioned complete protection against biting insects from the simultaneous use of permethrin-impregnated clothing as well as repllents on exposed skin. The effectiveness of impregnated clothing in the prevention or reducing of insect-borne diseases is not yet fully understood and the level of protection provided varies according to the vectors, impregnated fabrics and location. In general, there is reliable evidence which suggest that impregnated fabric can provide effective protection against insect bites, and providing relative protection against vector-borne diseases in bites. Nonetheless, simultaneous use of impregnated clothes and insect repellents on the skin can provide complete protection against bites and consequent disease. This approach is recommended for protection of high-risk personnel such as soldiers and outdoor workers, as well as travelers and tourists to protect against biting insects and vector-borne diseases.
L’endothélium est impliqué dans de nombreux processus physiologiques et physiopathologiques tels que les phénomènes d’inflammation, d’angiogenèse, de prolifération de cellules musculaires lisses et du métabolisme de nombreux médiateurs notamment hormonaux. Ces travaux de thèse avaient pour objectif d’étudier l’endothélium sous deux aspects pouvant conduire à des pathologies : l’angiogenèse et la dysfonction endothéliale. La première étude a permis de mettre en évidence un effet pro-angiogénique in vitro et in vivo du DEET, un répulsif anti-moustiques. Cet effet était associé à une augmentation de la production du monoxyde d’azote (NO),de la phosphorylation de la focal adhesion kinase (FAK) et de l’expression du vascular endothelium growth factor (VEGF) et conduit, in fine, à une augmentation de la croissance tumorale sur un modèle de xénogreffe de tumeur chez la souris. De plus, ces travaux ont montré que l’effet du DEET était engendré au niveau endothélial par une activité inhibitrice sur l’acétyl cholinestérase ainsi que par une modulation allostérique du récepteur muscarinique M3. La deuxième partie consistait à étudier le rôle du stress du réticulum endoplasmique et de la protein-tyrosine phosphatase 1B(PTP1B), une enzyme régulant négativement la voie de l’insuline, dans la dysfonction endothéliale induite par le diabète de type 1 (DT1). Les résultats ont permis d’identifier PTP1B comme une cible potentielle pour le traitement de la dysfonction endothéliale dans le cadre du DT1. L’ensemble de ces travaux de thèse permet une meilleure compréhension de la physiopathologie de l’endothélium et par conséquent fournit des connaissances supplémentaires pour la prise en charge de pathologies impliquant l’endothélium.
Permethrin is a common pesticide spray applied to civilian clothing and military uniforms for protection against biting arthropods in an effort to reduce risks to arthropod-borne diseases. During mass clothing spray events, exposure is possible through the dermal, inhalation, and ingestion routes. The potentially exposed population during a spray event includes the pesticide applicator(s) and assistants/working party (i.e. personnel who handle clothing/uniforms by positioning on the ground, flipping, and removing clothing/uniforms after spraying is complete). Previous investigation is limited regarding permethrin exposure via multiple routes of entry. Additionally, most exposure assessments are limited to the pesticide applicators rather than assistants/working party that support applicator personnel. The purpose of this investigation was to conduct a multi-route exposure assessment for all personnel normally participating in mass permethrin military uniform treatments.
Sampling occurred during routine spray events performed by 13 U.S. Navy personnel (3 applicators and 10 assistants/working party) over two days. Personal exposures were measured via dermal sampling and area air sampling. Permethrin area air sampling and analysis was conducted using OVS-2 sampling media (OSHA Method 70) using a stratified random sampling approach. Dermal exposure was measured using dosimeter gloves (n=26) and a dermal patch (n=26) worn on the right forearm by study participants and were analyzed with NIOSH Method 9204 (draft).
All air samples were reported below the 0.4 µg/sample limit of quantification. Glove sample results ranged from 45-120,000 µg/sample and patch results ranged from 0.57-45 µg/sample. A repeated-measures ANOVA showed non-statistically significant differences in dermal concentrations (p-value= 0.8340) between the applicators and assistants/working party in patches and gloves. Results suggest dermal contact is the primary route of entry compared to inhalation when mass spraying clothing with permethrin. Similar dermal exposures between these two occupations may necessitate reconsidering risk assessment procedures, training and PPE requirements for mass spray uniform treatments. Additionally, while PPE requirements for applicators is highly regulated and include items such as Tyvek suits, chemical protective gloves, and air purifying respirators, PPE has historically not been regulated for assistants/working party. Similar dermal concentrations between these occupational groups suggests assistants/working party personnel have un-met exposure assessment needs.
N,N-diethyl-meta-toluamide (DEET) is the most widely used active ingredient in commercial insect repellents. In addition to its adverse effects in insects, DEET can affect non-target organisms in surface water systems. Nevertheless, the aquatic life criteria of DEET are not available. This study conducted both acute and chronic toxicity tests on DEET in native Chinese aquatic species, and derived its criterion maximum concentration (CMC) and criterion continuous concentration (CCC). The determined CMC and CCC of DEET were 21.53 and 0.52 mg/L, respectively. The toxicity data indicated that DEET exposure posed a higher toxicity to some algae than other aquatic species. Compared with other insect repellents, DEET exposure posed a moderate toxicity to aquatic species. Therefore, the exposure concentration of DEET in Chinese surface water was collected to assess the potential ecological risk. The preliminary ecological risk assessment showed that DEET posed negligible risk to aquatic ecosystems in China. However, considering its toxic effects on the growth and reproduction to aquatic organisms, the ecological risk posed by DEET is worth further concern.
The ticks, fleas, mosquitoes, and other ectoparasites, in addition of being nuisance, transmit infectious diseases in companion and livestock animals and wildlife. The use of ectoparasiticides on companion and farm animals appears to be inevitable. Currently, synthetic insecticides of various classes are used to combat ectoparasites on animals. Some of the synthetic insecticides are used as ovicides or larvicides, while others are used as adulticides. But due to their greater toxicity, lack of selective toxicity, and pesticide resistance in insects, their use has been on decline. During the past two decades, the quest for natural products as an alternative to synthetic pesticides has been recognized. This chapter describes some biopesticides which can be used to control ectoparasites in pets and farm animals.
Insects enter every passible space on the planet. Despite our best efforts, flying insects infiltrate slightly open windows in domiciles, automobiles, storage spaces, and more. Is this ubiquitous experience a consequence of insect abundance and probability, or are flying insects adept at detecting passageways? There remains a lack of understanding of insect effectiveness in finding passage through the voids and imperfections in physical barriers in response to attractants, a topic particularly critical to the area of insect-borne disease control. In this study, we recorded the passage of Aedes aegytpi mosquitoes through voids in vertically oriented bed net fabrics within a cylindrical flight arena. We model the probability mosquitoes will discover and navigate the void in response to a physical attractant by observing their search behavior and quantifying the region within a void that is physically navigable, constrained by body size. Void passage rates were lower than that would be expected by purely randomized search behaviors and decline rapidly as the void diameter approaches the in-flight width of the insect.
United States military troops in the field are exposed to the environment and are thus at high risk for transmission of arboviruses, and degradation of mission from continual harassment from insects. Passive vector control, such as application of residual insecticides to US military materials common in the field such as tents and camouflage netting, has been shown to be effective and can contribute to a successful integrated vector management (IVM) plan in the field to reduce this risk. However, other common US military field materials have not been evaluated with residual pesticides. In this study we conducted the first known investigation of the efficacy and longevity of a residual pesticide containing λ-cyhalothrin applied to HESCO® blast protection wall geotextile. We exposed treated material to a temperate Florida environment and found that this treatment can be effective against sand flies, filth-breeding flies, and mosquitoes for at least 6 wk. This study provides evidence that residual treatment of this US military material may be leveraged as an IVM component to enhance the US Department of Defense pest management system.
Two transfluthrin-based spatial repellent products (Raid Dual Action Insect Repellent and Home Freshener and Raid Shield (currently not commercially available), SC Johnson, Racine WI) were evaluated for spatial repellent effects against female Aedes aegypti (L.) mosquitoes under laboratory (wind tunnel) and semi-field (outdoor enclosure) conditions. The placement of either product in the wind tunnel significantly reduced host-seeking behaviors. The mean baseline (control) landing counts for the Raid Dual Action and Raid Shield were reduced by 95% and 74% respectively. Mean probing counts for the Raid Dual Action were reduced by 95%, while the probing counts for the Raid Shield were decreased by 69%. Baseline blood-feeding success was significantly reduced for both treatments: Raid Dual Action (100%) and Raid Shield (96%). Semi-field evaluations were conducted in outdoor enclosures at the Navy Entomology Center of Excellence, Jacksonville, Florida. A moderate reduction in mosquito entry into military style tents resulted when either product was placed near the tent opening. The Raid Shield reduced mosquito entry into tents by 88%, while the Dual Action decreased entry by 66%.
Avian arboviral surveillance is an integral part of any disease-based integrated mosquito control program. The Harris County Public Health Mosquito and Vector Control Division has performed arboviral surveillance in the wild birds of Harris County and the City of Houston since 1965. Blood samples from live trapped birds were tested for arboviral antibodies to West Nile virus (WNV), St. Louis encephalitis, Eastern equine encephalitis, and Western equine encephalitis. A dead bird surveillance program was created in 2002 with the arrival of WNV in Harris County. Since implementation, the program has detected considerable variability in viral activity with annual WNV seroprevelance rates ranging from 2.9% to 17.7%, while the percentage of positive dead birds has ranged from 0.3% to 57.2%. In 2015, 1,345 live birds were sampled and 253 dead birds were tested, with WNV incidence rates of 16.5% and 5.9%, respectively.
Background:
Malaria is an important cause of illness and death across endemic regions. Considerable success against malaria has been achieved within the past decade mainly through long-lasting insecticide-treated nets (LLINs). However, elimination of the disease is proving difficult as current control methods do not protect against mosquitoes biting outdoors and when people are active. Repellents may provide a personal protection solution during these times.
Objectives:
To assess the impact of topical repellents, insecticide-treated clothing, and spatial repellents on malaria transmission.
Search methods:
We searched the following databases up to 26 June 2017: the Cochrane Infectious Diseases Group Specialized Register; the Central Register of Controlled Trials (CENTRAL), published in the Cochrane Library; MEDLINE; Embase; US AFPMB; CAB Abstracts; and LILACS. We also searched trial registration platforms and conference proceedings; and contacted organizations and companies for ongoing and unpublished trials.
Selection criteria:
We included randomized controlled trials (RCTs) and cluster-randomized controlled trials of topical repellents proven to repel mosquitoes; permethrin-treated clothing; and spatial repellents such as mosquito coils. We included trials that investigated the use of repellents with or without LLINs, referred to as insecticide-treated nets.
Data collection and analysis:
Two review authors independently reviewed trials for inclusion, extracted the data, and assessed the risk of bias. A third review author resolved any discrepancies. We analysed data by conducting meta-analysis and stratified by whether the trials had included LLINs. We combined results from cRCTs with individually RCTs by adjusting for clustering and presented results using forest plots. We used GRADE to assess the certainty of the evidence.
Main results:
Eight cRCTs and two RCTs met the inclusion criteria. Six trials investigated topical repellents, two trials investigated insecticide-treated clothing, and two trials investigated spatial repellents.Topical repellentsSix RCTS, five of them cluster-randomized, investigated topical repellents involving residents of malaria-endemic regions. Four trials used topical repellents in combination with nets, but two trials undertaken in displaced populations used topical repellents alone. It is unclear if topical repellents can prevent clinical malaria (RR 0.65, 95% CI 0.4 to 1.07, very low certainty evidence) or malaria infection (RR 0.84, 95% CI 0.64 to 1.12, low-certainty evidence) caused by P. falciparum. It is also unclear if there is any protection against clinical cases of P. vivax (RR 1.32, 95% CI 0.99 to 1.76, low-certainty evidence) or incidence of infections (RR 1.07, 95% CI 0.80 to 1.41, low-certainty evidence). Subgroup analysis of trials including insecticide-treated nets did not show a protective effect of topical repellents against malaria. Only two studies did not include insecticide-treated nets, and they measured different outcomes; one reported a protective effect against clinical cases of P. falciparum (RR 0.40, 95% CI 0.23 to 0.71); but the other study measured no protective effect against malaria infection incidence caused by either P. falciparum or P. vivax.Insecticide-treated clothingInsecticide-treated clothing were investigated in trials conducted in refugee camps in Pakistan and amongst military based in the Colombian Amazon. Neither study provided participants with insecticide-treated nets. In the absence of nets, treated clothing may reduce the incidence of clinical malaria caused by P. falciparum by approximately 50% (RR 0.49, 95% CI 0.29 to 0.83, low-certainty evidence) and P. vivax (RR 0.64, 95% CI 0.40 to 1.01, low-certainty evidence).Spatial repellentsTwo cluster-randomized RCTs investigated mosquito coils for malaria prevention. We do not know the effect of spatial repellents on malaria prevention (RR 0.24, 95% CI 0.03 to 1.72, very low certainty evidence). There was large heterogeneity between studies and one study had high risk of bias.
Authors' conclusions:
There is insufficient evidence to conclude topical or spatial repellents can prevent malaria. There is a need for better designed trials to generate higher certainty of evidence before well-informed recommendations can be made. Adherence to daily compliance remains a major limitation. Insecticide-treated clothing may reduce risk of malaria infection in the absence of insecticide-treated nets; further studies on insecticide-treated clothing in the general population should be done to broaden the applicability of the results.
Avian arboviral surveillance is an integral part of any disease-based integrated mosquito control program. The
Harris County Public Health Mosquito and Vector Control Division has performed arboviral surveillance in
the wild birds of Harris County and the City of Houston since 1965. Blood samples from live trapped birds were
tested for arboviral antibodies to West Nile virus (WNV), St. Louis encephalitis, Eastern equine encephalitis,
and Western equine encephalitis. A dead bird surveillance program was created in 2002 with the arrival of
WNV in Harris County. Since implementation, the program has detected considerable variability in viral activity
with annual WNV seroprevelance rates ranging from 2.9% to 17.7%, while the percentage of positive dead
birds has ranged from 0.3% to 57.2%. In 2015, 1,345 live birds were sampled and 253 dead birds were tested,
with WNV incidence rates of 16.5% and 5.9%, respectively.
A field evaluation of a new area repellent system, Thermacell Mosquito Repellent (TMR, cis-trans allethrin), was conducted against phlebotomine sand flies and mosquitoes in Cunpolat village, Sanlıurfa Province, in southeastern Anatolia, Turkey, an area historically endemic for cutaneous leishmaniasis and high sand fly populations. The objective of this study was to determine the efficacy, duration of protection, and spatial characteristics of protection (downwind distance from point of release), of the TMR. Twelve adult volunteers (nine in the treatment and three controls) made collections from ankle to knee for 25 min every hour from 2100 to 0300 on six consecutive nights in August 2002. Treatment consisted of placing a TMR unit at the middle of the village and then placing human bait collectors at 2.3, 4.6, and 7.6 m away from the repellent unit. Results from the field tests showed highly significant protection provided by the TMR from attack by Phlebotomus papatasi (Scopoli) (P < 0.001) and Ochlerotatus caspius (Pallas) (P < 0.001) for up to 4 h postapplication. In the six nights that tests were done, a total of 949 sand flies and 1095 mosquitoes were collected from the untreated control sites. Only 86 sand flies and 83 mosquitoes were collected at all distances from the places treated with TMR. These results indicated that reduction in sand fly and mosquito biting rates in treated groups ranged from 87.5 to 97.7% (mean protection 92%) and 90.2-97.4% (mean protection 93%), respectively. The percentage reduction values were maintained above 90.0% for 6 h of the assessment period. Overall, the number of bites by the cutaneous leishmaniasis vector Ph. papatasi and also Oc. caspius was reduced >11-fold and 13-fold, respectively, by the TMR.
Pictorial keys to the adults and larvae of the known genera of mosquitoes, subgenera of culex and the species of Culex Culex of Southwestern Asia and Egypt are provided for the use of field workers. Reasons are given for placing Culex deserticola Kirkpatrick in the subgenus Maillotia. Keywords: Illustrations; Reprints.
The systematic literature covering the nominal taxa which comprise the subgenus Melanoconion of Culex is reviewed and summarized under the subgeneric and valid species names. The catalog lists 155 valid names, 83 junior synonyms, and 13 nomina dubia. Type data, annotated literature citations, and known distribution are provided for each valid species name and junior synonyms. The kind of type specimen and its repository, if these exist, are indicated for each nominal species. Literature citations include the authorship of synonymies, and annotations of information relevant to the concept, taxonomy, distribution, and biology of the species. The known distribution of each species is indicated by country records. The text is supplemented by virtually all previously published illustrations of male genitalia to assist users in making species determinations. Collection data for voucher specimens which document new country records and tabular listings of the various life stages and distribution of each species are presented in separate appendices.
Repellent efficacy of N,N-diethyl-3-methyl-benzamide (deet), the piperidine, 1-[3-cyclohexen-1-ylcarbonyl]-2-methylpiperidine (AI3-37220), and a 1:1 ratio of deet + AI3-37220 were evaluated topically (0.25 mg/cm2 applied in ethanol solution) on human volunteers against the mosquito Aedes communis (DeGeer) and the black fly Simulium venustum Say. The average repellency of all three formulations was >95% at 4 h. For both mosquitoes and black flies, deet alone provided <90% protection at 6 h, whereas AI3-37220 provided >95% protection. Although repellent treatments were not significantly different overall, the contrasts between AI3-3720 versus deet were significant at 6 and 8 h. The 95% confidence interval on percent repellency at 6 h ranged from 90.1 to 98.9% for AI3-37220 versus 64.3 to 82.2% for deet, and at 8 h ranged 76.1 to 88.5% for AI3-37220 versus 47.8 to 64.0% for deet. Similarly, the confidence interval for protection against black flies at 6 h by (AI3-37220 ranged from 86.3 to 99.5% and did not overlap with the confidence interval provided by deet alone (51.2 to 78.8%). There was no evidence of synergistic repellency from a combination of the two compounds; i.e., protection from combined compounds was no better than either repellent used alone.
A standardized nomenclature for the costal wing scale spots of species of the genus Anopheles and other spotted-wing mosquitoes is proposed. Emphasis is placed on species of An. (Anopheles), Arribalzagia Series, which have three unique costal regions: the sector pale, the subcostal area, and the preapical pale. An isolated dark spot (the subcostal dark) distal to the sector dark spot at the end of the subcostal vein serves to define the series. The sector pale and accessory sector pale spots are defined in relation to the subcostal (sc-r) and radial (r1−rs) crossveins, and the preapical pale and apical pale spots are defined in relation to the end of vein R,. These morphological markers, along with the humeral crossvein and the end of the subcostal vein, are used to establish reference points for the definition of the other costal spots. The significance of these spots in the classification of the genus Anopheles is discussed. Wing spots are illustrated for species of An. (Anopheles) Arribalzagia Series, An. (Cellia), An. (Lophopodomyia), An. (Kerteszia), An. (Anopheles), An. (Nyssorhynchus), Orthopodomyia, Aedeomyia, Culex, and Aedes (Finlaya) Kochi Group.
To better understand the mechanism of insect repellency and to identify new repellent candidates, we performed a three-dimensional quantitative structure-activity (QSAR) study and developed a pharmacophore model for potent repellent activity from a set of eleven known diverse insect repellent compounds by using the CATALYST 3D-QSAR methodology. The protection time for repellent activity of the compounds was taken from an earlier published study. The pharmacophore was found to have three hydrophobic sites (two aliphatic and one aromatic) and a hydrogen-bond acceptor site in specific locations in the three dimensional geometry of the molecules that are critical for potent repellent activity. The pharmacophore showed an excellent correlation (correlation=0.9) between the experimental protection time afforded by the compounds in the training set and their predicted protection time. The validity of the pharmacophore model goes beyond the list in the training set and is found to map well on a variety of other insect repellents. By mapping this model on one of the more potent analogue we have generated a three-dimensional shape based template which allowed a search of our in-house compound database and discover four new potential insect repellent candidates.
Identification keys are provided for female adults and fourth stage larvae of the mosquito species likely to transmit dengue viruses in 4 regions of the world. The keys are illustrated with Auto-Montage(R) photomicrographs, allowing optimum depth of field and resolution. Species included for the Afrotropical Region are: Aedes (Stegomyia) aegypti (Linnaeus), Ae. (Stg.) africanus (Theobald), Ae. (Stg.) albopictus (Skuse), Ae. (Stg.) luteocephalus (Newstead), Ae. (Stg.) opok Corbet and Van Someren, Ae. (Diceromyia) furcifer (Edwards), and Ae. (Dic.) taylori Edwards; for the South Pacific Islands and Australian Region: Ae. (Stg.) aegypti, Ae. (Stg.) albopictus, Ae. (Stg.) cooki Belkin, Ae. (Stg.) hebrideus Edwards, Ae. (Stg.) hensilli Farner, Ae. (Stg.) polynesiensis Marks, Ae. (Stg.) rotumae Belkin, Ae. (Stg.) scutellaris (Walker), and Ochlerotatus (Finlaya) notoscriptus (Skuse); for the Oriental Region: Ae. (Stg.) aegypti, Ae. (Stg.) albopictus, and Oc. (Fin.) niveus subgroup; and for the American Region (North, Central and South America, including the Caribbean Islands): Ae. (Stg.) aegypti, Ae. (Stg.) albopictus, and Oc. (Gymnometopa) mediovittatus (Coquillett).
An illustrated key to the female anopheline mosquitoes of Central America from western Panama to the southern border of the United States is presented with a taxonomic summary and distribution table. Thirty-nine species and one subspecies are treated: Chagasia (1), Anopheles (Anopheles) (25 and one subspecies), An. (Kerteszia) (2), An. (Lophopodomyia) (1), An. (Nyssorhynchus) (9) and An. (Stethomyia) (1).
Permethrin impregnated netting was tested against Tanzanian populations of Anopheles arabiensis Patton, An.gambiae Giles and An.funestus Giles in experimental huts fitted with traps to catch samples of the mosquitoes existing during the night. Treated bednets killed some mosquitoes and increased the tendency of survivors to exit during the night. Treated cotton did not perform so well as treated nylon bednets. An impregnated bednet in which holes had been cut, to simulate a torn net, reduced the number of mosquitoes which fed and survived approximately as well as an intact untreated net. Treated curtains around the eaves of experimental huts did not perform so well as bednets but caused considerable reductions in the number of mosquitoes which fed and survived. However, there was no such effect when treated netting was placed around the eaves of a dwelling house. When one child slept under a treated net and another slept outside the net in the same hut, the number of bites on the latter child was less than if neither child had been under a net. Various aspects of the applicability of permethrin impregnated nets on a community basis are discussed.
The efficacy of permethrin when applied from a pressurized aerosol dispenser containing a 0.5% formulation was determined by field assays against natural infestations of Amblyomma americanum (L.) in eastern Oklahoma. Single applications of 60, 30, and 15 sec to cotton clothing provided complete (100%) protection for three successive 1-h daily exposures of human subjects to tick-infested habitat. The residual activity and concentrations of permethrin in the treated clothing were determined by adult mosquito assays and gas-chromatographic analyses in the laboratory.
Dengue fever (DF) was considered to be a potential cause of febrile illness in U.S. troops deployed to Somalia during Operation Restore Hope in 1992-1993. A prospective study of hospitalized troops with fever and a seroepidemiologic survey of 530 troops were conducted. Among 289 febrile troops hospitalized, 129 (45%) did not have an identified cause of their fever. Dengue (DEN) virus was recovered from 41 (43%) of 96 of these patients by inoculation of admission sera into C6/36 cell cultures. Thirty-nine (41%) of the isolates were identified as DEN-2 and two (2%) as DEN-3 by an indirect immunofluorescent antibody assay. An additional 18 (49%) of 37 culture-negative cases were shown by immunoglobulin M (IgM) antibody capture enzyme-linked immunosorbent assay to have anti-DEN virus antibody. All identified DF cases recovered within 1-2 weeks; no case of dengue hemorrhagic fever or shock syndrome was observed. A seroepidemiologic survey of a unit (n = 494) with 17 culture or serologically identified DF cases and a 13% attack rate of unidentified febrile illness revealed a 7.7% prevalence of anti-DEN virus IgM antibody. Failure to use bed nets was the only identified risk factor for DEN infection (adjusted odds ratio = 2.2, 95% confidence interval = 1.4-3.0). These data indicate that DF was an important cause of febrile illness among US troops in Somalia, and demonstrate the difficulties in preventing DEN infection in troops operating in field conditions.
IR3535, KBR3023, para-Menthane-3,8-diol (PMD), and deet were evaluated in controlled studies with human subjects (n = 5) for repellency to black salt marsh mosquitoes (Ochlerotatus taeniorhynchus Wiedemann), in the Everglades National Park, FL. In tests of 6-h duration, with an average mosquito biting pressure on exposed forearm skin of 19.5 (+/- 13.7) bites per minute, the mean percent repellencies (SE) for IR3535, KBR3023, PDM, and deet was 88.6 (3.2), 97.5 (1.7), 89.2 (2.9), and 94.8 (2.5), respectively. Mean complete protection times (SE) for IR3535, KBR3023, PMD), mean deet were 3.0 (1.0), 5.4 (0.6), 3.8 (1.4), and 5.6 (0.5) h, respectively. Untreated (ethanol) controls provided 0% repellency. When mosquito biting rates on the untreated forearm skin of repellent-treated subjects were compared with biting rates on the forearm skin of control subjects, the former were 23%-40% lower early in tests and as much as 22% higher late in tests. These differences cast doubt on the technical merit of test designs comprising evaluation of more than one repellent at a time on the same human subject while underscoring the importance of untreated subjects as negative controls in field repellent bioassays.
The effect of insecticide (permethrin)-treated bed nets (ITNs) on the spatial distribution of malaria vectors in neighboring villages lacking ITNs was studied during a randomized controlled trial of ITNs in western Kenya. There was a trend of decreased abundance of Anopheles gambiae with decreasing distance from intervention villages both before (P = 0.027) and after (P = 0.002) introduction of ITNs, but this trend was significantly stronger after ITNs were introduced (P = 0.05). For An. funestus, no pre-intervention trend was observed (P = 0.373), but after the intervention, a trend of decreased abundance with closer proximity to intervention compounds developed (P = 0.027). Reduction in mosquito populations in villages lacking ITNs was most apparent in compounds located within 600 meters of intervention villages. Sporozoite infection rates decreased in control areas following the introduction of ITNs (P < 0.001 for both species), but no spatial association was detected between sporozoite rates and distance to nearest intervention village. We conclude that high coverage of ITNs is associated with a community-wide suppression of mosquito populations that is detectable in neighboring villages lacking ITNs, thereby affording individuals residing in these villages some protection against malaria.
The insect repellents 3535 (ethyl butylacetylaminopropionate or IR3535) and deet (N,N-diethyl-3-methylbenzamide) were prepared as 20% solutions in absolute ethanol and evaluated for repellency against many mosquito species in Thailand under laboratory and field conditions using human subjects. In the laboratory, 0.1 ml was applied per 30-cm2 of exposed area on a volunteer's forearm (0.66-0.67 mg active ingredient [AI]/ cm2), whereas in the field, volunteers' legs (from knee to ankle, with a surface area of about 712-782 cm2) were treated with 3 ml per exposed area (0.76-0.84 mg AI/cm2). In the laboratory, both IR3535 and deet showed equal repellency (P > 0.05) for 9.8 and 9.7 h against Aedes aegypti, for 13.7 and 12.7 h against Culex quinquefasciatus, and for 14.8 and 14.5 h against Cx. tritaeniorhynchus, respectively. Anopheles dirus was significantly less sensitive to IR3535 than to deet (P < 0.05), with a mean protection time of 3.8 and 5.8 h, respectively. Under field conditions, both IR3535 and deet provided a high degree of protection against various mosquito vectors ranging from 94 to 100% during the test periods. Both repellents provided a high level of protection for at least 8 h against Ae. albopictus and for at least 5 h against Cx. gelidus, Cx. tritaeniorhynchus, Cx. quinquefasciatus, Mansonia dives, Ma. uniformis, Ma. annulata, Ma. annulifera, Anopheles minimus, and An. maculatus. This study clearly documents the potential of IR3535 for use as a topical treatment against a wide range of mosquito species belonging to several genera.
A field evaluation of a new area repellent system, Thermacell Mosquito Repellent (TMR, cis-trans allethrin), was conducted against phlebotomine sand flies and mosquitoes in Cunpolat village, Sanliurfa Province, in southeastern Anatolia, Turkey, an area historically endemic for cutaneous leishmaniasis and high sand fly populations. The objective of this study was to determine the efficacy, duration of protection, and spatial characteristics of protection (downwind distance from point of release), of the TMR. Twelve adult volunteers (nine in the treatment and three controls) made collections from ankle to knee for 25 min every hour from 2100 to 0300 on six consecutive nights in August 2002. Treatment consisted of placing a TMR unit at the middle of the village and then placing human bait collectors at 2.3, 4.6, and 7.6 m away from the repellent unit. Results from the field tests showed highly significant protection provided by the TMR from attack by Phlebotomus papatasi (Scopoli) (P < 0.001) and Ochlerotatus caspius (Pallas) (P < 0.001) for up to 4 h postapplication. In the six nights that tests were done, a total of 949 sand flies and 1095 mosquitoes were collected from the untreated control sites. Only 86 sand flies and 83 mosquitoes were collected at all distances from the places treated with TMR. These results indicated that reduction in sand fly and mosquito biting rates in treated groups ranged from 87.5 to 97.7% (mean protection 92%) and 90.2-97.4% (mean protection 93%), respectively. The percentage reduction values were maintained above 90.0% for 6 h of the assessment period. Overall, the number of bites by the cutaneous leishmaniasis vector Ph. papatasi and also Oc. caspius was reduced > 11-fold and 13-fold, respectively, by the TMR.
The insect repellents N,N-diethyl-3-methylbenzamide (Deet) and the racemate and 1S,2'S stereoisomer of 2-methylpiperidinyl-3-cyclohexene-1-carboxamide (AI3-37220) were tested against Anopheles albimanus Wiedemann and Aedes aegypti (L.) in laboratory human-volunteer assays. Estimated skin doses of Deet or racemic AI3-37220 required to reduce biting by 95% in Ae. aegypti were 2.3 and 3.5 x 10(-2) micromol/cm2 skin, respectively, whereas estimated doses for 95% bite reduction of An. albimanus in an approximately 40-yr-old laboratory colony established from El Salvador were 5 times higher at 12 x 10(-2) micromol Deet/cm2 skin and >20 x 10(-2) micromol/cm2 skin for AI3-37220. In tests with the 1S,2'S stereoisomer of AI3-37220, a newly established colony of An. albimanus from Belize bit less aggressively than El Salvador An. albimanus. However, the Belize-derived mosquitoes were as resistant as the old El Salvador colony to repellent effects of 1S,2'S stereoisomer of 2-methylpiperidinyl-3-cyclohexene-1-carboxamide. Earlier workers surmised that usual skin doses of Deet would offer only limited protection against An. albimanus in the field. Our findings support this speculation, but they also indicate that doses of Deet higher than those needed for protection against Ae. aegypti might offer reasonable protection against An. albimanus. Results indicate that neither racemate nor 1S,2'S stereoisomer of 2-methylpiperidinyl-3-cyclohexene-1-carboxamide offer as much protection as Deet against An. Albimanus, despite being highly effective against Ae. aegypti.
The subgenus Stegomyia Theobald of the genus Aedes Meigen in the Afrotropical Region is characterized. Eleven species groups are recognized and diagnosed. The taxonomy, distribution, bionomics and medical importance of the species of the region are discussed and summarized. Keys and illustrations are provided for the identification of the 11 species groups and 59 species and subspecies known to occur in this region. Information on the present status of the species of the African Stegomyia is summarized. Six new species: Aedes ealaensis, ethiopiensis, gandaensis, hogsbackensis, mpusiensis and sampi are recognized. Aedes blacklocki Evans is restored to specific status. One subspecies, denderensis Wolfs is elevated to specific status.
The influenza epidemic of 1918 killed more people in one year than the Great War killed in four, sickening at least one quarter of the world's population. In Fever of War, Carol R. Byerly uncovers the startling impact of the 1918 influenza epidemic on the American army, its medical officers, and their profession, a story which has long been silenced. Through medical officers' memoirs and diaries, official reports, scientific articles, and other original sources, Byerly tells a grave tale about the limits of modern medicine and warfare. The tragedy begins with overly confident medical officers who, armed with new knowledge and technologies of modern medicine, had an inflated sense of their ability to control disease. The conditions of trench warfare on the Western Front soon outflanked medical knowledge by creating an environment where the influenza virus could mutate to a lethal strain. This new flu virus soon left medical officers' confidence in tatters as thousands of soldiers and trainees died under their care. They also were unable to convince the War Department to reduce the crowding of troops aboard ships and in barracks which were providing ideal environments for the epidemic to thrive. After the war, and given their helplessness to control influenza, many medical officers and military leaders began to downplay the epidemic as a significant event for the U. S. army, in effect erasing this dramatic story from the American historical memory.
Thirty-three N,N-diethylamides, chiefly of aromatic acids, were prepared for testing as insect repellents. The most promising mosquito repellents of this series were derived from the ring-substituted benzoic acids. Some structural correlations are discussed.
Bulletin of the History of Medicine 80.1 (2006) 186-187
The influenza pandemic of 1918–19 was the worst single demographic disaster of the twentieth century. The death toll was somewhere between thirty and one hundred million people, more than the total deaths attributed directly and indirectly to the Great War. In the United States 675,000 people died—undoubtedly a conservative estimate that fails to take account of the harsh shadow cast by the virus. The flu came in three waves, the most lethal of which was the second, in the fall of 1918. The virus spread rapidly, and all the achievements of modern medicine and public health could not stem its malevolent progress or heal the infected. Influenza was a known killer but usually of the weak, the young, and the elderly; the 1918–19 outbreak additionally and universally killed preponderantly more men aged twenty to forty years, the very cohort that might be thought best able to resist the infection. In the last ten years a number of both scholarly and popular books on the pandemic have appeared, but the outbreak has also been ignored by many historians surveying the last century. Epidemiologists continue to warn that a further pandemic will occur—hence the serious attention continually given to avian flu in southeast Asia.
Conventional scholarship argues that the pandemic originated in a military camp in Kansas in March 1918, and that troopships helped to spread the infection across the Atlantic to Europe. However, recent research indicates that flulike symptoms were present in the densely crowded British military camp at Étaples, France, during the winter of 1916. Carol Byerly's careful study focuses on the role of the U.S. Army during the pandemic, with greater detail than is provided in earlier studies. Using a wide range of official sources, private papers and diaries, and contemporary periodicals, she analyzes the influenza pandemic within the context of the preparation for war, military mobilization, the expansion of the medical department, and the transport by troopship of the American Expeditionary Forces to camps in France from which they were sent into action in the trenches of the Western Front. The high morbidity and mortality from flu, Byerly argues, drastically hindered the 35th Division in the Meuse-Argonne campaign of September–November 1918, although senior military men and the subsequent congressional inquiry downplayed or effectively ignored the impact of the disease. At all stages influenza hit the Army hard. In earlier wars, for example the Philippines campaign, more soldiers died from disease than as a result of enemy action. The United States, in its short involvement in the First World War, exceptionally among the belligerent powers again lost more men through disease, largely as a result of influenza: one in four soldiers suffered from flu, and more than 50 percent of all wartime deaths were from its consequences.
In the penultimate chapter of this excellent book Byerly addresses the question of why the pandemic was largely ignored by the authors of the multivolume official history, The Medical Department in the World War. Her persuasive analysis is that they leaned on racialist theories to explain the incidence of disease rather than on material factors such as housing and clothing. "Using race as a primary analytical tool," she argues, "camouflaged other relevant factors and obscured a more accurate understanding of how army policies and practices could promote death and disease in the ranks" (p. 167). Medical professionals were also anxious not to promote their failure to control influenza, which sat ill with ideas of progress and medicine's triumphalist record in conquering disease. Fever of War adds an important dimension to knowledge of the influenza pandemic of 1918–19.
1. See Nature, 2005, 435 (7041): 399–401.
In dealing with present day problems of malaria, attention in this paper will be centered on potential benefits forthcoming as a result of wartime experience and wartime research. From this experience and research, important advances in the field of malariology have followed. In particular, they have contributed to improved methods in the treatment of malaria and to new approaches in regard to prevention.CLINICAL MALARIA
Army and Navy statistics1 for World War II reveal a total of 572,950 reported admissions for malaria. Actually, it is probable that, had complete reporting been possible, the total would have more nearly approximated a million admissions. Whatever the exact figure, clinical experience on an unprecedented scale was gained, and as a result many interesting and exceedingly important developments took place in the field of clinical malaria.
Basic studies on the mosquito fauna of Thailand were undertaken by the Department of Medical Entomology, United States Army Component-Southeast Asia Treaty Organization (SEATO) in 1961. At present, studies on the taxonomy, biology, distribution and disease relationships of the mosquitoes of the Kingdom are continuing with considerable emphasis on the malaria vectors of the genus Anopheles. As these studies progressed it became apparent that there was no single source to which entomologists, malariologists, and other public health workers could refer to for assistance in identifying female Anopheles mosquitoes captured in epidemiological studies. The earlier references did not adequately cover the species which we found in the country, and the newer publications on single species or species groups were too scattered to be useful. Thus, the present illustrated key grew out of a recognized need for a single reference source which would permit the identification of all of the Anopheles mosquitoes which we now recognize as occurring here. The preparation of the present key is part of a cooperative effort between this Department, The Walter Reed Army Institute of Research and the Smithsonian Institution.* Related publications now in preparation include an annotated checklist of the Anopheles of Thailand, with notes on biology and distribution, and a full systematic treatment of the males, females and immature stages. The key has been made as simple as possible, consistent with the need for accuracy in identification. The morphological nomenclature used follows that of Belkin (1962) with minor modifications. All of the structures named in the key are illustrated in the figures on Plates I thru XIX. The illustrations, which add immeasurably to the utility of the key, are based on actual specimens collected in Thailand or adjacent areas.
An illustrated key for the identification of the female Anopheles mosquitoes of southwestern Asia and Egypt is presented. Thirty-nine species and three subspecies are treated, including 25 species and one subspecies of Anopheles (Cellia) and 14 species and two subspecies of Anopheles (Anopheles). A new species from Egypt of the subgenus Cellia closely related to Anopheles stephensi Liston is left unnamed. Anopheles (Anopheles) pseudopictus Grassi is removed from synonomy with Anopheles (Anopheles) hyrcanus (Pallas), and Anopheles (Anopheles) habibi Mulligan and Puri is recognized as a junior synonym of Anopheles (Anopheles) claviger (Meigen). Tables providing important taxonomic references and the geographic distribution for each species are included.
The french private squinted at the unbearable tropical sun beating down on him. He was baking in the humid heat of this accursed island, Saint Domingue. As he lay on his back on the lush, green vegetation, he could not move a muscle. The stiffness of his body echoed the pain in his head. Occasionally, he would vomit black fluid from his weakening body. After a few hours, he became delirious, mumbled his wife's name, and lost consciousness.