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Phlebotominae sand fly distribution in the three survey areas (Foz do Iguaçu, Santa Terezinha de Itaipu and transects) Satellite image free downloaded from https://landsatlook.usgs.gov/.
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Every year about 3 million tourists from around the world visit Brazil, Argentina and Paraguay´s triple border region where the Iguaçu Falls are located. Unfortunately, in recent years an increasing number of autochthonous canine and human visceral leishmaniasis (VL) cases have been reported. The parasite is Leishmania (Leishmania) infantum and it...
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Metacyclic Leishmania promastigotes are transmitted by sand flies that inject parasites and saliva into the host's skin. Previous studies have demonstrated that DNA plasmids encoding Lutzomyia longipalpis salivary proteins LJM17 and LJL143, when used to immunize dogs, resulted in a systemic and local Th1 cell-mediated immunity that interfered in pa...
In Latin America, zoonotic visceral leishmaniasis (ZVL) arising from infection by L. infantum is primarily transmitted by Lutzomyia longipalpis sand flies. Dogs, which are chronic reservoirs of L. infantum, are considered a significant risk factor for acquisition of ZVL due to their close proximity to humans. In addition, as a vector-borne disease...
Objective: To determine the spatial distribution and infection rate of sand flies as vectors of Leishmania parasite in Ardabil province, northwest of Iran.
Methods: This was a descriptive cross-sectional study. The sand flies were collected from 30 areas in all 10 districts of Ardabil province during 2017. The specimens were caught using the sticky...
Background
Discovered by Nicolle and Comte in 1908 in Tunisia, Leishmania infantum is an intracellular protozoan responsible for zoonotic canine leishmaniosis (CanL) and zoonotic human visceral leishmaniasis (HVL). It is endemic in several regions of the world, including Tunisia, with dogs considered as the main domestic reservoir. The geographic e...
Human visceral leishmaniasis (HVL) is a neglected disease that occurs in 98 countries on five continents, and it is endemic in tropical and subtropical regions. In South America, the etiological agent of HVL is Leishmania infantum (syn. Leishmania chagasi), mainly transmitted through the bite of an infected sandfly female from the genus Lutzomyia....
Citations
... Nyssomyia neivai is a suspected vector of L. (V.) braziliensis in the South of Brazil [41]. The ability of this sand fly to acquire infection from L. (V.) braziliensis-infected hamsters has already been reported [42]. ...
American tegumentary leishmaniasis (ATL) is highly endemic in the Amazon basin and occurs in all South American countries, except Chile and Uruguay. Most Brazilian ATL cases are due to Leishmania (Viannia) braziliensis, however other neglected Amazonian species are being increasingly reported. They belong to the subgenus L. (Viannia) and information on suitable models to understand immunopathology are scarce. Here, we explored the use of the golden hamster Mesocricetus auratus and its macrophages as a model for L. (Viannia) species. We also studied the interaction of parasite glycoconjugates (LPGs and GIPLs) in murine macrophages. The following strains were used: L. (V.) braziliensis (MHOM/BR/2001/BA788), L. (V.) guyanensis (MHOM/BR/85/M9945), L. (V.) shawi (MHOM/BR/96/M15789), L. (V.) lindenbergi (MHOM/BR/98/M15733) and L. (V.) naiffi (MDAS/BR/79/M5533). In vivo infections were initiated by injecting parasites into the footpad and were followed up at 20- and 40-days PI. Parasites were mixed with salivary gland extract (SGE) from wild-captured Nyssomyia neivai prior to in vivo infections. Animals were euthanized for histopathological evaluation of the footpads, spleen, and liver. The parasite burden was evaluated in the skin and draining lymph nodes. In vitro infections used resident peritoneal macrophages and THP-1 monocytes infected with all species using a MOI (1:10). For biochemical studies, glycoconjugates (LPGs and GIPLs) were extracted, purified, and biochemically characterized using fluorophore-assisted carbohydrate electrophoresis (FACE). They were functionally evaluated after incubation with macrophages from C57BL/6 mice and knockouts (TLR2-/- and TLR4-/-) for nitric oxide (NO) and cytokine/chemokine production. All species, except L. (V.) guyanensis, failed to generate evident macroscopic lesions 40 days PI. The L. (V.) guyanensis lesions were swollen but did not ulcerate and microscopically were characterized by an intense inflammatory exudate. Despite the fact the other species did not produce visible skin lesions there was no or mild pro-inflammatory infiltration at the inoculation site and parasites survived in the hamster skin/lymph nodes and even visceralized. Although none of the species caused severe disease in the hamster, they differentially infected peritoneal macrophages in vitro. LPGs and GIPLs were able to differentially trigger NO and cytokine production via TLR2/TLR4 and TLR4, respectively. The presence of a sidechain in L. (V.) lainsoni LPG (type II) may be responsible for its higher proinflammatory activity. After Principal Component analyses using all phenotypic features, the clustering of L. (V.) lainsoni was separated from all the other L. (Viannia) species. We conclude that M. auratus was a suitable in vivo model for at least four dermotropic L. (Viannia) species. However, in vitro studies using peritoneal cells are a suitable alternative for understanding interactions of the six L. (Viannia) species used here. LRV1 presence was found in L. (V.) guyanensis and L. (V.) shawi with no apparent correlation with virulence in vitro and in vivo. Finally, parasite glycoconjugates were able to functionally trigger various innate immune responses in murine macrophages via TLRs consistent with their inflammatory profile in vivo.
... There is a significant correlation between the geographical region and Leishmania infection outcomes (p < 0.001), highlighting the influence of location on disease prevalence. This finding is pivotal as it aligns with the Stockholm Paradigm, which posits that pathogens can expand beyond their traditional ecological niches, adapting to new hosts and environments [38,39,56]. ...
Leishmaniosis is a vector-borne disease caused by protozoan parasites of the genus Leishmania, which are zoonotic and have an important impact on animal and public health globally. Between 2009 and 2023, blood samples from domestic dogs with clinical suspicion of leishmaniosis were received from 286 veterinary medical centres throughout mainland Portugal. An enzyme-linked immunosorbent assay (ELISA) was utilised to detect antibodies against Leishmania infantum antigens. Additionally, a complete blood count and tests for total proteins, urea, creatinine and alanine aminotransferase, as well as protein electrophoresis, were also performed. No significant relationship between sex and breed was observed. The age distribution was bimodal, with the highest prevalence of disease occurring at 2–5 years of age and a secondary peak occurring at 6 years or over (p < 0.001). No statistical correlation was observed between creatinine and urea across the ELISA serological groups. In contrast, both the gamma globulin levels (r = 0.45; p < 0.001) and the albumin/globulin ratio (r = −0.36; p < 0.001) exhibited moderate correlations with the ELISA. These findings support recent seroprevalence studies in dogs, with some geographical areas in Northern Portugal exhibiting the highest values, which may be the result of geographical shifts in parasite circulation due to climate change.
... Nyssomyia neivai is a confirmed vector of Le. braziliensis, primarily in South Brazil. This sand fly has been reported carrying Le. braziliensis DNA in the states of Paraná [36] and Rio Grande do Sul [37]. Moreover, its role in transmitting Le. infantum is also suspected, as molecular detections have identified this parasite in the states of Paraná [38], Santa Catarina [39], and MG in the Southeast Region of the country [40]. ...
This study investigated the sand fly fauna of the municipality Iguatama, in the Midwest Region of Minas Gerais state, Brazil, including Leishmania infection rates and blood meal sources. Sand flies were collected during four periods over the course of a single year, encompassing both dry and rainy seasons, using CDC light traps placed in peridomiciles where dogs were seropositive for visceral leishmaniasis (VL). A total of 762 sand fly specimens, representing 12 species across seven genera, were collected. Lutzomyia longipalpis was the most abundant species, comprising 57.6% of the collected specimens, followed by Nyssomyia neivai (19.6%) and Nyssomyia whitmani (10.5%). Species richness and diversity varied among collection periods, with the highest diversity observed in January 2019. Molecular analysis detected Leishmania DNA in 12.5% of the sand fly specimens, with Le. infantum being the predominant species. Blood meal analysis revealed feeding on multiple vertebrate species, including humans, rats, dogs, and chickens. The presence of Leishmania DNA in sand flies, and the identification of human blood meals, highlight the potential role of these species in VL transmission. These findings underscore the importance of continued surveillance and control measures to prevent the spread of VL and reduce transmission risk in the region.
... (10) The municipality of Foz de Iguaçu has in its sand fly fauna the predominant species Lu. longipalpis, and it is where the third detection of the presence of DNA from L. infantum in Ny. neivai was reported. (11) This scenario increasingly reinforces the need to study the natural infection of Ny. neivai and other species in VL endemic areas, regardless of the presence of Lu. longipalpis. Thus, this study used the multiplex polymerase chain reaction (PCR) methodology and sequencing in sand flies captured in the municipality of Itaperuçu, located in Vale do Ribeira, Paraná, to evaluate the natural infection in sand flies. ...
... Previously, the circulation of this parasite had only been reported in the municipality of Foz do Iguaçu. (11) Vector species are geographically distributed in their respective transmission cycles, adapted to the abiotic factors of that habitat. However, as external interactions such as anthropic, climatic, and spatial actions start to act in that originally preserved environment, the distribution of these species can narrow the relationship between the etiological agent and other vectors that are not part of their natural cycle. ...
BACKGROUND The incidence of visceral leishmaniasis (VL) has increased in the Southern region of Brazil in recent years, especially in the State of Paraná. New species have been suggested with potential to act as vector in VL endemic areas. OBJECTIVES Identify the Leishmania species in sand fly specimens collected from 2016 to 2018 in the municipality of Itaperuçu, Vale do Ribeira, Paraná, Brazil. METHODS Light traps were used for collections and for the analysis of sand fly were used the multiplex polymerase chain reaction (PCR) methodology and subsequent sequencing. FINDINGS Among the collected specimens, 88.62% were attributed to the species Nyssomyia neivai, which were grouped into 176 pools. Three positive pools were detected: two with Leishmania (Viannia) braziliensis and one with L. (Leishmania) infantum. The positivity rate for the parasite was 0.25% based on the presence of at least one infected insect in the pool. MAIN CONCLUSIONS The detection of L. infantum in Ny. neivai draws attention due to its abundance and anthropophily in the State of Paraná. Moreover, this finding is considered as an alert and suggests that the vector competence of Ny. neivai and the criteria for its incrimination should be carried out, given its wide distribution in southern of Brazil.
... Dogs are the main reservoirs in urban areas. They may show severe clinical signs and assist in the spread of the parasite from vectors such as Phlebotomus and Lutzomyia sandfly bites [2]. VL cases have increased in recent years in both Europe and America with a dispersion to previously unreported locations such as Uruguay and the United States [3]. ...
Leishmaniasis is a zoonotic disease with worldwide distribution. In the Americas, the causative agent of the visceral form is the protozoa Leishmania (Leishmania) infantum. Transmission to the host or vertebrate reservoir occurs through the bite of infected arthropod females like Lutzomyia longipalpis. The epidemiological connection between the infection in dogs and humans generate constant studies about the relationship between the parasite and the canine host, including the development of methods and tests for the detection and quantification ofLeishmania (L.) infantum. Both conventional PCR (cPCR) and quantitative PCR (qPCR) can be used in the diagnosis of the parasite. Dropet Digital PCR (ddPCR) is another useful tool. Knowing the parasite load and its relationship with the clinical signs of naturally infected dogs is useful in research development and for establishing treatments that reduce the transmission of the disease. In this study, thirty-nine clinical samples of spleen from dogs naturaly infected by L. infantum were collected after necropsy. Two molecular tools were used to quantify the parasite load (qPCR and ddPCR) and there was 100% agreement in the results of the them. The tools developed in this work are important for the detection of L. infantum in dogs and humans. Droplet Digital PCR does not require a standard curve and is easy to standardize. In such manner, this new tool can generate more in-depth information in the broad debate about parasitic loads and the pathogenesis of leishmaniasis.
... During the last four decades, the migration of populations from rural to urban areas has led to the rapid urbanization of VL. Moreover, unplanned urbanization encompassing adjacent rural areas where the zoonotic cycle of leishmaniasis occurs promotes its rapid spread and infection among humans [8][9][10][11][12][13][14]. A major environmental change in Brazil that caused a VL epidemic was the construction of gas pipelines in the 1990s [15], which had signi cant consequences for the geographic expansion of VL and cutaneous leishmaniasis (CL) [3,14,16]. ...
... In 2012, the presence of the vectors was con rmed on the Brazilian side [22]. In that regard, a transversal study on sand y dispersal in the far west of Paraná showed that vectors and reservoirs of CL and VL were present in that region [13,23]. Identifying variables such as transmission risk periods and abiotic factors can lead to more speci c prevention and control strategies. ...
... In a previous transversal study, we showed that different sand y species are present in many areas of Foz do Iguaçu. However, in certain patches, they are found in higher density, forming hotspots [13]. From that point on, such hotspots were grouped into four landscape units (strata) for the conduction of the present longitudinal study: A, B, C, and D (Fig. 1). ...
Background: The recent geographic expansion of Leishmania infantum vectors in the triple border area of Argentina, Brazil, and Paraguay has highlighted the need to know the seasonality, parasite infection rate, and the factors that contribute the dispersal and handling of this parasite.
Methods: Entomological, quantitative longitudinal studies were conducted in Foz do Iguaçu, Brazil, where sand fly abundance was higher in cross-sectional studies. Monthly sand fly samplings occurred in 2014-2015. LeishmaniaDNA was detected by PCR and subsequently sequenced, classified, and the infection rate was estimated. The study also featured an observational and descriptive design. Environmental variables were analyzed at the micro- and mesoscales, and the data were evaluated along with entomological and infection inputs.
Results: A total of 3,582 sand flies were caught. Lutzomyia longipalpiswas the predominant species (71.5%) among 13 species found in one year of sampling. Four species, Evandromyia edwardsi, Expapillata firmatoi, Micropygomyia ferreirana, and Pintomyia christenseni were reported for the first time. The NDVI, distance from water, sex, west-to-east wind, and wind speed were significant variables for the intra-environment presence and/or abundance of vectors. The presence and/or abundance of vectors in peri-domicile were influenced by rain, altitude, maximum temperature, minimum and maximum relative humidity, west-to-east wind, wind speed, and sex. Considering PCR positivity, females infected with L. infantum were found throughout the year, and especially with Lu. longipalpis (prevalence means of 16.4).
Conclusions: Vector colonization concentrates on urban and peri-urban hotspot areas, with some individuals being present in various parts of the city and few sites showing high vector abundance. This distribution suggests that the risk of actual contact between humans and parasitic vectors in urban areas during the epidemic period is associated with patches of peri-urban vegetation and then spreads across urban areas. We can state that, in the period of this study, the most critical transmission phase for L. infantum in the region is from January to May. Therefore, future management plants to reduce access to reservoirs might reduce sand fly infection and consequently human and animal infections.
... In jungle environments Lu. longipalpis relative abundance is usually 5% or less ( Thomaz-Soccol et al. 2018;de Souza Freitas et al. 2018), but reaches between 80% and 100% in colonized urban areas, while its absolute abundance can grow from 5 times to more than 250 times once the environment is anthropized Vilela et al. 2011). In relation to the dispersal-urbanization of the vector observed mainly since 1980 (Salomón et al. 2015), this process has been associated at macroscale with environmental modifications due to the construction of roads, dams, and infrastructure works such as the Bolivia-Brazil gas pipeline in the State of Mato Grosso do Sul , unplanned urbanization, deforestation in "fishbone" shape, and road network and intensity of exchange between neighboring localities . ...
Human hookworm infection is linked to a variety of factors, such as poverty, inadequate living conditions, absence of adequate sanitary facilities, cultural habits, and ineffective prevention programs/health systems. Zoonotic hookworm infection, leading to cutaneous larva migrans in humans, is related to the presence of animals (dogs and cats) serving as reservoirs. Climate and soil structure are also important determinants for larval development in the environment, and consequently for both human and animal hookworm infections. Health systems usually focus on individual medicalization, leading eventually to antiparasitic overuse and development of drug resistances. Given the reduced sustainability and effectiveness of the community interventions observed over the last decades, there is a need for more comprehensive approaches. In this chapter, we discuss the One Health Approach as a multidisciplinary measure to control hookworm disease. Integrated control programs would reduce transmission sustainably, for example, by combining mass drug administration aiming at the entire population rather than only schoolchildren or other defined target groups, and expansion of sanitary improvement programs. Once available, widespread application of a hookworm vaccine will be an additional tool to further boost control efforts. Health professionals involved in specific control programs should integrate into an interdisciplinary manner differing disciplines and departments. Existing overlapping disease control programs should be integrated, to achieve sustainable and cost-effective control on the long run, of both human and animal hookworm infection, and hookworm-related cutaneous larva migrans, in addition to other neglected tropical diseases.KeywordsOne health approachHookwormsAnimal hookwormsCutaneous larva migrans
... neivai, the vector associated with typical CL, is the dominant species in the peri-urban and rural areas where most of the reported CL cases occur. Even though the vectors of CL have been found to be infected with L. infantum elsewhere (Moya et al., 2017;Thomaz-Soccol et al., 2018), their role as vectors of this par- Table 4. Performance metrics obtained for the threshold criteria maximum sensitivity plus specificity for the best models fitted for two sample sizes (n=25 and n=74). ...
In this work we assessed the environmental factors associated with the spatial distribution of a cutaneous leishmaniasis (CL) outbreak during 2015-2016 in north-eastern Argentina to understand its typical or atypical eco-epidemiological pattern. We combined locations of human CL cases with relevant predictors derived from analysis of remote sensing imagery in the framework of ecological niche modelling and trained MaxEnt models with cross-validation for predictors estimated at different buffer areas relevant to CL vectors (50 and 250 m radii). To account for the timing of biological phenomena, we considered environmental changes occurring in two periods, 2014-2015 and 2015-2016. The remote sensing analysis identified land cover changes in the surroundings of CL cases, mostly related to new urbanization and flooding. The distance to such changes was the most important variable in most models. The weighted average map denoted higher suitability for CL in the outskirts of the city of Corrientes and in areas close to environmental changes. Our results point to a scenario consistent with a typical CL outbreak, i.e. changes in land use or land cover are the main triggering factor and most affected people live or work in border habitats.
... A LV está distribuída em 21 unidades federadas do BR e foi considerada indene na região sul do país até 2006 e 2009, quando houve a primeira notificação de caso autóctone canino e humano, respectivamente, no RS (Figueiredo et al., 2012;CEVS, 2011;Azevedo et al., 2009) Em 2019, segundo o informe epidemiológico das Américas (OMS/OPAS, 2020) houve redução de 27% (937) dos casos de LVH no BR, no entanto houve aumento de casos na AR, no PY e no UY e foi realizada a primeira notificação pela Bolívia, embora a transmissão autóctone já tivesse sido confirmada em anos anteriores. Considerando o aumento de casos de LVH em países fronteiriços com a região sul e a eminência de casos em municípios brasileiros, fatores como a migração de trabalhadores e animais infectados para construção da rota leste-oeste do gasoduto Bolivia-Brasil, associados ao desmatamento da década de noventa, são discutidos como prováveis causas da emergência da LV no estado do PR (Thomaz-Soccol et al., 2018;OMS/OPAS, 2017;Oliveira et al., 2006;Grill & Zurmendi, 2017 A notificação de LVH no país é realizada através do Sinan net após suspeita pelo profissional de saúde. Já nos casos de LVC, a notificação não segue um fluxograma definido claramente, o que evidencia na prática, em áreas não endêmicas, a falta de preparo dos municípios para agirem frente às suspeitas. ...
... Cronologia da notificação dos casos autóctones de leishmaniose visceral canina e humana nos três estados da região sul do Brasil. Fonte: Autores (2021).Na região sul, a LV ocorre principalmente em cidades que fazem fronteira com Uruguai (UY), Paraguai (PY) e Argentina (AR)(Thomaz-Soccol et al., 2018;Salomón et al., 2008;Salomón et al., 2011), como pode-se observar na Figura 2. ...
A leishmaniose visceral (LV) foi considerada indene na região sul do país até 2006, quando houve a primeira notificação de caso autóctone canino no município de São Borja no Rio Grande do Sul. Nos estados de Santa Catarina e Paraná, a autoctonia em caninos ocorreu nos anos 2010 e 2012 respectivamente. Na região sul, por ser de instalação recente, além das poucas notificações, observa-se a falta da inclusão da enfermidade nos diagnósticos diferenciais na clínica humana e veterinária, sendo a prevalência da LV maior que o registro de casos notificados. Assim, objetivou-se revisar a situação da LV humana e canina (LVC) e a presença dos vetores na região sul do país. Foram consideradas publicações oficiais sobre a doença entre 2009 e 2020 e consultadas as bases de periódicos online. Foram encontradas informações conflitantes quanto ao número de casos e localidade da infecção, que podem ser consequência da mudança na padronização dos registros de LV humana, da descentralização e falta de uniformidade nos registros de LVC, além da divulgação dos diagnósticos através de boletins epidemiológicos anuais desatualizados. Requer atenção da vigilância e dos pesquisadores o flebotomíneo Lutzomyia gaminarai, espécie endêmica no sul do Brasil, pela proximidade filogenética com a Lutzomyia longipalpis.
... Rural-urban migration and expansion of human settlements in peri-urban areas have also increased contact between vectors and both humans and domestic animals. The interconnection between human settlements contributes to the life cycle and dispersion of leishmaniasis vector (Thomaz-Soccol et al., 2018). As a result, sand flies have adapted the transmission cycle to urban environments where rather than depend on reservoirs restricted to areas with dense vegetation, they rely on domestic animals (Vianna et al., 2016). ...
Leishmaniasis is a vector-borne disease caused by the protozoan Leishmania spp. mainly affecting individuals of low socioeconomic status. In tropical regions the transmission risk to humans depends not only on environmental factors, such as vegetation cover and climate, but also on the socioeconomic characteristics of human populations. However, the relative contribution of these factors to disease risk and incidence is not well understood. Yet this information is critical for the development of epidemiological surveillance schemes and control practices. Leishmaniasis cases have increased in São Paulo state, Brazil over recent years but the underlying risk factors for transmission remain understudied. Here, we use generalized linear mixed models to quantify the association between occurrence and incidence (number of cases) of cutaneous (CL) and visceral (VL) leishmaniasis from 1998 to 2015, and landscape (native vegetation cover), climate (seasonal and interannual variation in precipitation and temperature) and socioeconomic factors (population, number of cattle heads, Human Development Index - HDI, Gini inequality index and income per capita) across the 645 municipalities of São Paulo state, Brazil. For CL, probability of occurrence was greater in municipalities with high native vegetation cover and economic inequality and in years with greater average winter precipitation. For VL, probability of occurrence was greater in years with high minimum spring precipitation and maximum annual temperatures, and in municipalities with larger HDI values and a greater number of cattle heads. The number of VL cases increased during years with high mean fall precipitation and, for both CL and VL the number of cases was greater in years of high annual mean temperature. Understanding how these risk factors influence spatial and temporal variation in the risk and incidence of leishmaniasis can contribute to the development of effective public health policies and interventions.
