Dataset Information

Diversity of Leptospira spp. in Rats and Environment from Urban Areas of Sarawak, Malaysia.

ABSTRACT: Various prevalence studies on Leptospira in animals and humans, as well as environmental samples, had been conducted worldwide, including Malaysia. However, limited studies have been documented on the presence of pathogenic, intermediate, and saprophytic Leptospira in selected animals and environments. This study was therefore conducted to detect Leptospira spp. in rats, soil, and water from urban areas of Sarawak using the polymerase chain reaction (PCR) method. A total of 107 rats, 292 soil samples, and 324 water samples were collected from April 2014 to February 2015. Pathogenic Leptospira was present in 5.6% (6/107) of rats, 11.6% (34/292) of soil samples, and 1.9% (6/324) of water samples. Intermediate Leptospira was present in 2.7% (8/292) of soil samples and 1.9% (6/324) of water samples. Saprophytic Leptospira was present in 10.3% (11/107) of rats, 1.4% (4/292) of soil samples, and 0.3% (1/324) of water samples. From this study, 76 Leptospira spp. were isolated. Based on DNA sequencing, the dominant Leptospira spp. circulating in urban areas of Sarawak are pathogenic Leptospira noguchii, intermediate Leptospira wolffii serovar Khorat, and saprophytic Leptospira meyeri, respectively. Overall, this study provided important surveillance data on the prevalence of Leptospira spp. from rats and the environment, with dominant local serovars in urban areas of Sarawak.

SUBMITTER: Pui CF

PROVIDER: S-EPMC5350390 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Diversity of Leptospira spp. in Rats and Environment from Urban Areas of Sarawak, Malaysia.

Pui Chai Fung CF Bilung Lesley Maurice LM Apun Kasing K Su'ut Lela L

Journal of tropical medicine 20170228

Various prevalence studies on Leptospira in animals and humans, as well as environmental samples, had been conducted worldwide, including Malaysia. However, limited studies have been documented on the presence of pathogenic, intermediate, and saprophytic Leptospira in selected animals and environments. This study was therefore conducted to detect Leptospira spp. in rats, soil, and water from urban areas of Sarawak using the polymerase chain reaction (PCR) method. A total of ...[more]

PMID: 28348601

Similar Datasets

Project description:BACKGROUND:Leptospirosis is considered a neglected zoonosis associated with infrastructure problems and low socioeconomic status, particularly slums. Since the disease is mainly transmitted in urban settings by rat urine, this risk factor may be important predictor tool for prompt control and effective prevention at the local level in urban endemic areas. Accordingly, the present study aimed to propose an early spatial predictor tool for human leptospirosis in urban settings, to test the methodology of molecular methods for assessing Leptospira spp. in trapped rats, and report associated environmental data. METHODOLOGY/PRINCIPAL FINDINGS:Official city records and previous study were used to select risk factors for human leptospirosis in an endemic neighborhood of Curitiba, Brazil. Neighborhood census sectors were divided in high- and low-risk areas using 12 selected factors: flood area, water supply, water course, green coverage, afforestation, sewage network, open sewage, open garbage, garbage collection, dumpster, pavement, and rodent complaints. In addition, rats were captured in pre-determined sites from January through March 2017, euthanized, and individual kidneys samples sent for molecular diagnosis. Human cases were obtained from official city records. In total, 95/112 (84.8%) census sectors were classified as low-risk to human leptospirosis. No significant statistical differences were found in human case frequencies between high and low-risk areas. Kidney samples from 17/25 (68.0%) trapped rats were positive for Leptospira spp. The main risk factors associated with rodent presence included inadequate water supply (p = 0.04), sanitary sewage (p = 0.04), unpaved streets (p = 0.04), and complaint of rodents (p = 0.04). CONCLUSIONS/SIGNIFICANCE:This study offers a new approach to score leptospirosis transmission risk, and to compare small areas and their heterogeneity in the same census sector of endemic areas. Environmental risk factors for Leptospira spp. transmission within the neighborhood were mainly due to differences in infrastructure and basic services. To the author's knowledge, this is the first study using Leptospira spp. in rats as predictor for human disease in an urban setting of a major city. Although the number of rats trapped was low, this methodology may be used as basis for early and effective interventions, focused on high risk areas for leptospirosis prior to human cases, and potentially reducing morbidity and mortality in low-income areas of urban settings.

Project description:Leptospirosis is an emerging infectious disease of global significance, and is endemic in tropical countries, including Malaysia. Over the last decade, a dramatic increase of human cases was reported; however, information on the primary vector, the rat, and the Leptospira serovars circulating among the rat population is limited. Therefore, the present study was undertaken to isolate Leptospira and characterise the serovars circulating in the urban rat populations from selected main cities in Peninsular Malaysia.Rat trappings were carried out between October 2011 to February 2014 in five urban cities which were chosen as study sites to represent different geographical locations in Peninsular Malaysia. Microscopic agglutination test (MAT) and PCR were carried out to identify the Leptospiral serogroup and determine the pathogenic status of the isolates, respectively while pulsed-field gel electrophoresis (PFGE) and random amplified polymorphic DNA (RAPD)-PCR were used to characterize the isolates.Three rat species were identified from the three hundred and fifty seven rats captured with Rattus rattus, being the dominant rat species (285, 80 %) followed by Rattus norgevicus (53, 15 %) and Rattus exulans (19, 5 %). Only 39 samples (11.0 %) were positive by culture and further confirmed as pathogenic Leptospira by PCR. Significant associations were shown between host infection with locality, season, host-age and species. Based on MAT, two serogroups were identified in the population namely; L. borgpetersenii serogroup Javanica (n?=?16) and L. interrogans serogroup Bataviae (n?=?23). Pulsed-field gel electrophoresis (PFGE) distinguished the two serovars in the urban rat populations: L. borgpetersenii serovar Javanica (41 %), and L. interrogans serovar Bataviae (59 %). RAPD-PCR yielded 14 distinct patterns and was found to be more discriminative than PFGE.This study confirms two Leptospira serovars circulating among the urban rats population in Peninsular Malaysia namely; L. borgpetersenii serovar Javanica and L. interrogans serovars Bataviae. Despite the low number of isolates obtained from the rat population, this study suggests that rodent control programs and disease surveillance may help to reduce the possible risk of disease transmission.

Project description:BackgroundLeptospirosis has become an urban health problem as slum settlements have expanded worldwide. Efforts to identify interventions for urban leptospirosis have been hampered by the lack of population-based information on Leptospira transmission determinants. The aim of the study was to estimate the prevalence of Leptospira infection and identify risk factors for infection in the urban slum setting.Methods and findingsWe performed a community-based survey of 3,171 slum residents from Salvador, Brazil. Leptospira agglutinating antibodies were measured as a marker for prior infection. Poisson regression models evaluated the association between the presence of Leptospira antibodies and environmental attributes obtained from Geographical Information System surveys and indicators of socioeconomic status and exposures for individuals. Overall prevalence of Leptospira antibodies was 15.4% (95% confidence interval [CI], 14.0-16.8). Households of subjects with Leptospira antibodies clustered in squatter areas at the bottom of valleys. The risk of acquiring Leptospira antibodies was associated with household environmental factors such as residence in flood-risk regions with open sewers (prevalence ratio [PR] 1.42, 95% CI 1.14-1.75) and proximity to accumulated refuse (1.43, 1.04-1.88), sighting rats (1.32, 1.10-1.58), and the presence of chickens (1.26, 1.05-1.51). Furthermore, low income and black race (1.25, 1.03-1.50) were independent risk factors. An increase of US$1 per day in per capita household income was associated with an 11% (95% CI 5%-18%) decrease in infection risk.ConclusionsDeficiencies in the sanitation infrastructure where slum inhabitants reside were found to be environmental sources of Leptospira transmission. Even after controlling for environmental factors, differences in socioeconomic status contributed to the risk of Leptospira infection, indicating that effective prevention of leptospirosis may need to address the social factors that produce unequal health outcomes among slum residents, in addition to improving sanitation.

Project description:BackgroundRodent species are well known for their potential as hosts and reservoirs for various zoonotic diseases. Studies on blood parasite infection in small mammals focused on urban cities in Peninsular Malaysia and have been conducted over the years. In contrast, there are information gaps related to molecular detection of blood parasites in urban areas of Sarawak that are associated with veterinary importance and zoonotic spillover potential. Increasing prevalence and transmission of blood parasite diseases is the most crucial public health issue, particularly in developing urban areas of Sarawak. Therefore, molecular identification studies were performed to determine and identify the blood parasites infecting rodents.MethodsA total of 40 rodent blood samples were analysed for blood parasite infection and a combined approach using polymerase chain reaction-based technique, and traditional microscopic examination (blood smear test) was conducted. 18s rRNA (Plasmodium spp.) and cytochrome b (Hepatocystis spp.) gene marker were used to identify the blood parasites.ResultsNote that 67.5% (n = 27) blood samples were tested negative for blood parasites, while 32.5% (n = 13) blood samples collected were infected with at least one protozoan parasite. Out of 13 samples, 69.2% (n = 9) were detected with Hepatocystis sp., while 15.4% (n = 2) were positive with Hepatozoon ophisauri. Two individuals had multiple infections from both species. No Plasmodium spp. have been detected throughout this study using universal primer (targeted Plasmodium spp.); however, different parasite species which were H. ophisauri were detected.ConclusionAlthough there is no evidence of human infection from H. ophisauri and Hepatocystis sp. detected from the study, the data show the host species are heavily infected, and the information is essential for future prevention of zoonotic outbreaks and surveillance programmes. Therefore, it is suggested that the surveillance programmes should be incorporated in targeted areas with a high risk of disease emergence.

Dataset Information

Diversity of Leptospira spp. in Rats and Environment from Urban Areas of Sarawak, Malaysia.

Publications

Diversity of <i>Leptospira</i> spp. in Rats and Environment from Urban Areas of Sarawak, Malaysia.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets