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Leptospirosis, an emerging zoonotic disease in Malaysia

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Leptospirosis is an endemic disease in Malaysia and recently has received increasing attention mainly due to several recent incidents that have resulted in human mortality which have alarmed health professionals in Malaysia. The increasing incidence of leptospirosis in forested regions is associated with the bacteria infecting small wild mammals other than rats. Infection in wildlife could result in the introduction of new serovars to humans and domesticated animals. More research on leptospirosis and the screening of wildlife and humans near wildlife habitats is required to have a better understanding of the involvement of wildlife in the disease.
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... In the case of primates in Malaysia, interactions with domestic animals and humans can lead to cross-species transmission of diseases, compounding the risk of outbreaks. For instance, certain primates may carry zoonotic diseases that can infect humans or livestock, posing significant public health risks [8]. In Malaysia, dense populations of certain primates, such as macaques, have been associated with increased transmission rates of diseases like malaria and leptospirosis. ...
... To mitigate these risks, it is essential to implement effective management strategies for wildlife populations and reduce human-wildlife interactions. This includes measures such as improving waste management to reduce food sources for wildlife, enhancing surveillance and monitoring of zoonotic diseases, and promoting public awareness about the risks of wildlife-related diseases [8,9]. ...
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“Biodiversity overabundance” is a term used to describe a situation where species densities (the number of species in a given area) have become unsustainable and localized species densities have exceeded the carrying capacity of the ecosystem as a whole. As urbanization compresses wildlife habitats, excessive species density can lead to ecological imbalances, including competitive exclusion and declines in less competitive species. This study explores the impacts of high species density on biodiversity, resource competition, and human-wildlife interactions in Malaysia. The findings highlight intensified resource competition, increased disease transmission, and heightened human-wildlife conflicts, particularly in urban areas. Notable examples include the rise of zoonotic diseases linked to dense wildlife populations. To address these challenges, effective management strategies are proposed, including restoring predator-prey dynamics, implementing population control measures, and integrating urban planning with environmental protection. By balancing species density and fostering coexistence between humans and wildlife, Malaysia can promote sustainable biodiversity management and enhance ecosystem health. The study emphasizes the need for ongoing research and collaboration among stakeholders to mitigate the adverse effects of excessive species density and ensure long-term ecological stability.
... Being a notifiable disease, healthcare education plays an important role in aiding disease control and prevention (Thayaparan et al., 2013). These factors might have contributed to a higher level of knowledge among the working dog handlers but not the dog shelter handlers. ...
... The infected animals may become carriers with the organisms present in the renal tubules for periods of days, months to years and shed the leptospires in urine which then directly contaminate the environment. Human leptospirosis often resulted from direct or indirect contact with contaminated urine, water, mud or soil and with infected animals (Garba et al., 2017;Thayaparan et al., 2013, Alashraf et al., 2019Goh et al., 2019). ...
... This may cause delays in treatment and difficulties in determining the true incidence of the disease. The true status of leptospirosis requires collaboration between veterinary and medical researchers (8). Therefore, differential diagnosis methods, such as microscopic agglutination tests (MAT), indirect hemagglutination, immunoenzymatic assays (ELISA) and culturing from urine or tissues, are used to detect specific antibodies, and so dark field microscopy, immunostaining or polymerase chain reaction (PCR) are needed (9,10). ...
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Background: Abdominal bloating (AB) is a common, bothersome symptom that negatively affects most adults. Although social support may help people suffering from AB, limited validated questionnaire is available. This study aimed to validate the newly developed Abdominal Bloating Social Support (SS-Bloat) scale for the Malaysian context. Method: We conducted a cross-sectional study in which we used purposive sampling and a self-administered questionnaire. Based on the literature review, experts’ input and indepth interviews, new items were generated for SS-Bloat scale. Content validity was assessed by experts and pre-tested with 30 individuals with AB. Construct validity was determined based on exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). Reliability was determined based on Cronbach’s alpha and composite reliability (CR). Results: During the development stage, eight items were generated for SS-Bloat scale and remained the same after content validity and pre-testing. A total of 152 participants with a mean age of 31.27 years old (68.3% female, 32.7% male) completed the questionnaire. Based on the EFA, three problematic items were removed. The total variance explained was 35.6% with acceptable reliability (α = 0.66). The model was then tested using CFA. The initial model did not fit the data well. After several model re-specifications, the final measurement model of SS-Bloat scale fit the data well with acceptable fit indices (comparative fit index [CFI] = 0.994 and Tucker-Lewis index [TLI] = 0.984). The CR was satisfactory with value of 0.84. Conclusion: SS-Bloat scale was deemed valid and reliable for assessing the level of social support among AB patients. The questionnaire can be useful for both research studies and clinical purposes, as it is easy to use.
... Numerous diseases, such as Dengue fever, Hanta fever, and Leptospirosis [27], have a global prevalence. Infectious diseases are characterized by their ability to spread from person to person, in contrast to noninfectious diseases, which stem from inherited or environmental factors. ...
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... The disease is hence considered endemic to several tropical countries like Malaysia (Thaya et al., 2013) for instance. Leptospirosis is well-known as the rat-urine-disease ["penyakit kencing tikus" in the national language] and nicknamed "the Great Mimicker" (Ministry of Health Malaysia, 2011), as the symptoms bear deceptive resemblances to those of other diseases, and thus was always overlooked, underdiagnosed or misdiagnosed with malaria, dengue or other illnesses. ...
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Leptospirosis is one of the often-neglected fatal zoonotic diseases endemic to most developing countries. The disease transmits mostly through contact of rodent urine contaminated with pathogenic Leptospira in the environment. This review discusses the need for environmental bioremediation of these pathogens and the reasons phage could very well be employed for that purpose. With a few modifications like encapsulation and cocktail formulation, the functionality and stability of phage as the natural predator could easily be heightened. Host specificity, ability to auto-dose and co-evolve along its hosts, effectiveness against biofilms and independence of its production are some of the promising features of a phage. Here we also highlight the interactions and interference among phages in a cocktail, transduction probability, and hypothetic usage of phage lysin in biocontrolling pathogenic Leptospira.
... An important discovery was the fact that leptospirosis could infect practically all mammalian species, particularly rodents. Additionally, the domestic animals were the source of human infection (Thayaparan et al. 2013). Dutch researchers, isolated a strain from canines and continue to use this strain as the type strain for serovar Canicola (Francey et al. 2020). ...
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Leptospirosis, a zoonotic disease, is caused by pathogenic spirochetes belonging to the genus Leptospira. It is widely considered one of the most prevalent zoonoses in terms of both geographic distribution and the variety of animal species susceptible to acute illness or acting as renal carriers. Tropical and subtropical regions, such as Thailand, experience a higher incidence of leptospirosis in humans and animals, making it a significant public health concern in those areas.While clinical signs of leptospirosis in cats have yet to be thoroughly investigated, previous studies have shown that cats with polyuria and polydipsia are more likely to have anti-Leptospira antibodies. However, in cats, the clinical signs are usually mild, despite the presence of leptospires in their blood and urine. Reported clinical signs in infected cats (confirmed through MAT and/or PCR) include polyuria, polydipsia, haematuria, uveitis, lameness, lethargy, anorexia, weight loss, ascites, vomiting, diarrhea, pain on handling, and inflammatory lesions on the skin and digits. Various diagnostic tools can be employed, such as the microscopic agglutination test (MAT), indirect hemagglutination assay (IHA), or immuno-enzymatic assays (ELISA) to detect specific antibodies. Leptospira or their components can also be identified in urine or tissues through culture, dark field microscopy, immunostaining, or PCR.Human infections of leptospirosis can be acquired by individuals in certain occupations, such as veterinarians, farmers, animal caretakers, and researchers, as well as people exposed to pet dogs or domestic livestock during their daily activities. Farmers, veterinarians, and abattoir workers are particularly at risk due to their occupation.
... The tragedy and many others before it are a grim reminder to pay heed to safety and disaster preparations. Since time immemorial, floods, landslides and water surges brought on by the two monsoons in Malaysia have destroyed properties and infrastructure, besides causing the subsequent rise of diseases (e.g., leptospirosis) that threaten human lives (9). The greatest lesson may be learnt from the major floods that occurred from December 2014 to January 2015 during the northeast monsoon, which claimed 24 lives and displaced more than 200,000 people, besides incurring RM1 billion worth of economic losses (10). ...
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Landslides are one of the most destructive disasters in Malaysia, which frequently occurs during the southwest and northeast monsoons that bring heavy rain. In this commentary, we describe for the first-time disaster victim identification (DVI) protocols for the identification of landslide victims that occurred on an agricultural facility known as Father's Organic Farm and its adjacent campsite that claimed the lives of 31 campers. Since time immemorial, floods, landslides and water surges brought on by the two monsoons in Malaysia have destroyed properties and infrastructure, besides causing the subsequent rise of diseases (e.g., leptospirosis) that threaten human lives. Therefore, appropriate mitigation strategies at hill slopes and rivers near tourism sites and populated areas (e.g., installation of soil sensors and implementation of an early-warning system with appropriate evacuation plans) included in this commentary should be considered by policymakers and related agencies as extreme weather events may impact on the health and safety of residents and travellers.
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Introducción: La aplicación de los métodos morfométricos en las ciencias biomédicas favorece el conocimiento de muchas enfermedades como la leptospirosis, una enfermedad infecciosa bacteriana causada por leptospiras patógenas. Objetivo: Caracterizar las alteraciones morfométricas de corazón en crías de ratas Wistar infectadas con leptospira canícola durante la preñez, en el período septiembre 2017- septiembre 2019. Métodos: Se realizó un estudio experimental donde se formaron dos grupos: 12 ratas Wistar del grupo estudio y 24 del grupo control; solo fue inoculado con cepas del serogrupo leptospira canícola, el primer grupo. Todas se gestaron antes de ser inoculadas e inmediatamente de gestadas, las del grupo estudio, fueron inoculadas. Resultados: predominaron los machos en ambos grupos (52,50%); y se observó una disminución del peso y volumen del corazón con diferencias significativas entre ambos grupos y sexos. El promedio de variables morfométricas: longitud transversa, sagital y grosor del ventrículo izquierdo del corazón se comportó diferente en ambos grupos estudiados y mostró una disminución de las longitudes del corazón en las crías de ratas afectadas. Conclusiones: Predominaron los machos en ambos grupos en aproximadamente la mitad de las crías de ratas estudiadas; existió disminución del peso y volumen del corazón, resultado estadísticamente significativo. La longitud transversa, la sagital y el grosor del ventrículo izquierdo del corazón mostraron una disminución de las longitudes en las crías de ratas afectadas.
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In the past decade, leptospirosis has emerged as a globally important infectious disease. It occurs in urban environments of industrialised and developing countries, as well as in rural regions worldwide. Mortality remains significant, related both to delays in diagnosis due to lack of infrastructure and adequate clinical suspicion, and to other poorly understood reasons that may include inherent pathogenicity of some leptospiral strains or genetically determined host immunopathological responses. Pulmonary haemorrhage is recognised increasingly as a major, often lethal, manifestation of leptospirosis, the pathogenesis of which remains unclear. The completion of the genome sequence of Leptospira interrogans serovar lai, and other continuing leptospiral genome sequencing projects, promise to guide future work on the disease. Mainstays of treatment are still tetracyclines and beta-lactam/cephalosporins. No vaccine is available. Prevention is largely dependent on sanitation measures that may be difficult to implement, especially in developing countries.
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Large carnivores are of vital importance to the stability and integrity of most ecosystems, but recent declines in free-ranging populations have highlighted the potentially devastating effect of infectious diseases on their conservation. We reviewed the literature on infectious diseases of 34 large (maximum body mass of adults >20 kg) terrestrial carnivore species, 18 of which are considered to be threatened in the wild, and examined reports of antibody prevalence (seroprevalence) and cases of infection, mortality and population decline. Of 52 diseases examined, 44% were viral, 31% bacterial and the remainder were protozoal or fungal. Many infections were endemic in carnivores and/or infected multiple taxonomic families, with the majority probably occurring via inhalation or ingestion. Most disease studies consisted of serological surveys for disease antibodies, and antibody detection tended to be widespread implying that exposure to micro-organisms was common. Seroprevalence was higher in tropical than temperate areas, and marginally higher for infections known to occur in multiple carnivore groups. Confirmation of active infection via micro-organism recovery was less common for ursids than other taxonomic groups. Published descriptions of disease-induced population decline or extinction were rare, and most outbreaks were allegedly the result of direct transmission of rabies or canine distemper virus (CDV) from abundant carnivore species to less-common large carnivores. We conclude that the threat of disease epidemics in large carnivores may be serious if otherwise lethal infections are endemic in reservoir hosts and transmitted horizontally among taxa. To prevent or mitigate future population declines, research efforts should be aimed at identifying both the diseases of potential importance to large carnivores and the ecological conditions associated with their spread and severity.
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Leptospirosis is a zoonotic disease caused by pathogenic leptospiral bacteria, which are transmitted directly or indirectly from animals to humans or animal to animal. The first phase of this proposed study was carried out to determine the extent of exposure to leptospirosis in wild mammals surrounded by human settlements around wildlife or tourism area (Wind Cave, Fairy Cave, Bako National Park and Matang Wildlife Center). This study reports an incident of leptospirosis among primates (three captive and two free ranging), rats, bats, squirrels and mongoose around Kuching, Sarawak area, which has been screened for Leptospirosis. Blood samples were obtained to determine the presence of antibodies through the microscopic agglutination test (MAT) using eighteen serovars of Leptospira commonly found in Malaysia as antigens. It was observed that four out of the five monkeys (80%), rats (9/4) (44%), bats (20/5) (20.8%), squirrels 4/4 (100%) and mongoose (1) (100%) reacted against one or more serovars of Leptospira. In this study antibody of five serovars of Leptospira interrrogans Copenheni, Leptospira interrrogans Lai, Leptospira interrrogans Pomona, Leptospira interrrogans Pyrogenes, Lepto 175* were detected. Serovars Copenhegeni, Lai, Pomona and Pyrogenes were considered pathogenic for different mammals including human beings. No information about serovars lepto 175 and further studies going on. This is providing information on the possible zoonotic importance of mammalian species in maintaining this disease in Sarawak. The transmission of leptospires in rats reported several incidents and between primates, bats, squirrels, mongoose and human is not reported elsewhere but this could create new reservoir and transmission routes and may affect the tourism, conservation effort and public health. http://www.frst.unimas.my/images/stories/BJRST/vol2no2/9_bjrst-023-2012.pdf
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We analyzed the epidemiological data of all people who were involved in the search and rescue operation in Lubuk Yu, a natural recreational forest with waterfall and stream. The hospital admission records of the cases who fulfilled the case definition and the environmental samples result taken at Lubuk Yu recreational area were studied. 153 people were exposed to this outbreak, 85 (55.5%) were professional rescuers from various government agencies and 68 (44.5%) were villagers. 21 fulfilled the case definition. Ten cases were confirmed melioidosis, six melioidosis alone and four coinfected with leptospirosis. There were eight deaths in this outbreak, seven were villagers and one professional rescuer. Overall case fatality was 70%. All confirmed melioidosis cases and seven who died had diabetes mellitus. The morbidity rate were higher among the villagers, 23.5% compared to professional rescuers, 5.9%. The case fatality rate were also higher in this group which was 100% compared to 33.3% in professional rescuers. The soil and water samples in Lubuk Yu recreational area were positive for leptospira and Burkholderia pseudomallei. The presence of co-infection and co-morbidities especially diabetes mellitus among the exposed led to the high mortality in this outbreak hence a high index of suspicion is important among the healthcare professionals in the management of melioidosis cases. To avoid similar incident in future, search and rescue operation should be only conducted by professional rescuers with appropriate personal protective equipment. A register of rescuers should be maintained for surveillance and follow up if necessary.
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Co-infection of melioidosis and leptospirosis is uncommon. We report here four such cases, confirmed by blood culture for melioidosis and blood polymerase-chain reaction for leptospirosis, which occurred among rescuers involved in a search and rescue operation for a young man who was suspected to have drowned in Lubuk Yu, a recreational forest in Pahang, Malaysia. Despite treatment, three of the patients died from the co-infection. Copyright © 2012 by The American Society of Tropical Medicine and Hygiene.
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There have been repeated outbreaks of leptospirosis reported all over the world. Being one of the largest cities in the world, Hong Kong is no exception. We report a local case involved in an outbreak of the disease with a typical route of acquisition but rare complications. A brief account on the epidemiology of both Hong Kong and Southern China is given. Discussions on the pathophysiology of the disease and its complications are also presented.
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This chapter discusses the serological typing methods of Leptospires. They are the members of the Treponemataceae family. The genus includes strains which are parasitic or free living. Some strains may be pathogenic for man or various other animal species. When leptospira strains are classified, first the serogroup to which a strain belongs has to be determined by the microscopic agglutination test using selected rabbit group sera. The procedures used for the determination of the serotype status of a strain are derived from the definition of serotypes. Serotypes should be subdivided into varieties based on the presence of a thermolabile antigen. The relatively high specificity of host-serotype relationships means that accurate typing of isolated strains is one of the basic methods for epidemiological investigations. In studies dealing with pathogenic properties of strains-production of hemolysis, and lipases, knowledge of the serotype status is also essential.
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