Low Prevalence of Leptospira Carriage in Rodents in Leptospirosis-Endemic Northeastern Thailand (original) (raw)
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Epidemiology of Leptospira Transmitted by Rodents in Southeast Asia
PLoS Neglected Tropical Diseases, 2014
Background: Leptospirosis is the most common bacterial zoonoses and has been identified as an important emerging global public health problem in Southeast Asia. Rodents are important reservoirs for human leptospirosis, but epidemiological data is lacking.
Prevalence of Leptospira Infection in Rodents from Bangladesh
International Journal of Environmental Research and Public Health
Worldwide, Leptospira infection poses an increasing public health problem. In 2008, leptospirosis was recognised as a re-emerging zoonosis of global importance with South-East Asia being one of the most significant centres of the disease. Rodents are thought to be the most important host for a variety of Leptospira serovars. Because Bangladesh offers a suitable humid climate for the survival of these pathogenic bacteria, the presence of rodents could be a serious risk for human infection, especially in peri-urban areas or locations where food is stored. In order to gain more understanding of the multi-host epidemiology, a prevalence study was conducted in Comilla, Bangladesh to determine the presence of pathogenic Leptospira species in rodents. Real-time Polymerase Chain Reaction (qPCR) and sequencing showed that 13.1% (61/465) of the trapped rodents were infected with pathogenic Leptospira. Sequencing of the qPCR products identified the presence of three species: Leptospira interro...
PLoS neglected tropical diseases, 2017
Leptospirosis is a worldwide zoonotic bacterial disease caused by infection with leptospires. Leptospirosis in humans and livestock is an endemic and epidemic disease in Thailand. Livestock may act as reservoirs for leptospires and source for human infection. Data on leptospirosis infection in humans and livestock (Buffaloes, Cattle, and Pigs) species during 2010 to 2015 were analyzed. Serum samples were examined using Microscopic Agglutination Test (MAT) to identify antibodies against Leptospira serovars using a cut-off titer ≥ 1:100. The seroprevalence was 23.7% in humans, 24.8% in buffaloes, 28.1% in cattle, and 11.3% in pigs. Region specific prevalence among humans and livestock was found in a wide range. The most predominant serovars were Shermani, followed by Bratislava, Panama, and Sejroe in human, Shermani, Ranarum, and Tarassovi in buffaloes, and Shermani and Ranarum in cattle and pigs. Equally highest MAT titers against multiple serovars per one sample were found mainly in...
Pathogens
Leptospirosis is an important zoonotic disease that is transmitted worldwide through infected small mammals such as rodents. In Malaysia, there is a paucity of information on the animal reservoirs that are responsible for leptospirosis transmission, with only a few studies focusing on leptospirosis risk in recreational areas. Therefore, in this study we characterized the species composition and the prevalence of pathogenic Leptospira spp. in non-volant small mammals of Hutan Lipur Sekayu, Terengganu. We performed ten trapping sessions totaling 3000 trappings between September 2019 and October 2020. Kidney samples from captured individuals were extracted for the PCR detection of pathogenic Leptospira spp. Overall, we captured 45 individuals from 8 species (1.56% successful trapping effort), with 9 individuals testing positive for pathogenic Leptospira, that is, a 20% (n = 9/45) prevalence rate. Rattus tiomanicus (n = 22) was the most dominant captured species and had the highest posi...
Leptospirosis is caused by the spirochetal bacterium Leptospira of which rodents are considered the most important reservoir. This study aims to determine and characterize virulent Leptospira species among rodents and small mammals found in human settlements and recreational spots within the Hulu Langat and Gombak districts of Selangor, Malaysia; regions that frequently report probable human leptospirosis cases. Molecular analysis revealed an overall Leptospira detection rate of 14.3% among the 266 small mammals captured, and the human settlements were found to have the highest number of isolates (15.1%), followed by recreational sites (14.5%). The molecular characterization conducted based on the lipL32, secY genes and MLST revealed that the strains belonged to four different species, including; Leptospira interrogans (29; 76.3%; ST50, ST238, ST243), L. kirschneri (5; 13.15%; ST110), L. borgpetersenii (3; 8%; ST143) and L. weilii (1; 2.63%; ST242). The study revealed genotypes of circulating strains among small mammals in Malaysia, which include Leptospira locus ST110 L. kirschneri, ST 50 L. interrogans, ST143 L. borgpetersenii and ST242 L. weilii. Among the small mammals studied, 17/105 (16.2%) Rattus norvegicus, 7/59 (11.9%) of Rattus rattus, 5/24 (20.8%) of Maxomys whiteheadi, 4/18 (22.2%) of Sundamys muelleri, 2/22 (9%), Tupaia gliss, 2/16 (12.5%) Rattus tiomanicus and 1/4 (25%) of Suncus murinus carried pathogenic leptospires. The data from the present study may imply that, in addition to rodents, other small mammals also serve as maintenance hosts for Leptospira. Hence, much remains unknown about Leptospira maintenance hosts, and there is need for further investigation to ascertain the prevailing serovars of pathogenic Leptospira in Malaysia. This will assist in the development of efficient diagnostic assays with improved microscopic agglutination test (MAT) panels, and in the implementation of suitable prevention and control measures.
Survey of leptospirosis of small mammals in Thailand
The Southeast Asian journal of tropical medicine and public health, 2005
During 1999-2000, kidney tissues of approximately 15% of 1310 rodents trapped from northeastern provinces of Thailand were tested for the presence of leptospires. Our direct immunofluorescent assay (DFA) for detection of leptospires showed 100% sensitivity and 94% specificity with the culture data. Both methods identified R. norvegicus as the highest source of infection. Among isolated Leptospira, 137 were serotyped by cross agglutinin absorption and/or a microscopic agglutination, and gave some variations and similarities at the serovar level to the DFA results. DFA data demonstrated over half of the positive animals were infected with several serovars of Leptospira interrogans. A subsequent DFA study in Bangkok in 2002 revealed leptospiral infection in 33% of 42 rats and shrews. The most common infecting serovars were Autumnalis and Canicola identified in rural and urban animals, respectively. This finding suggests that wild small mammals may act as important sources of pathogenic...
PLOS Neglected Tropical Diseases, 2020
BackgroundLeptospirosis, commonly known as rat-urine disease, is a global but endemic zoonotic disease in the tropics. Despite the historical report of leptospirosis in Malaysia, the information on human-infecting species is limited. Determining the circulating species is important to understand its epidemiology, thereby to strategize appropriate control measures through public health interventions, diagnostics, therapeutics and vaccine development.Methodology/Principle findingsWe investigated the human-infecting Leptospira species in blood and serum samples collected from clinically suspected leptospirosis patients admitted to three tertiary care hospitals in Malaysia. From a total of 165 patients, 92 (56%) were confirmed cases of leptospirosis through Microscopic Agglutination Test (MAT) (n = 43; 47%), Polymerase Chain Reaction (PCR) (n = 63; 68%) or both MAT and PCR (n = 14; 15%). The infecting Leptospira spp., determined by partial 16S rDNA (rrs) gene sequencing revealed two pathogenic species namely Leptospira interrogans (n = 44, 70%) and Leptospira kirschneri (n = 17, 27%) and one intermediate species Leptospira wolffii (n = 2, 3%). Multilocus sequence typing (MLST) identified an isolate of L. interrogans as a novel sequence type (ST 265), suggesting that this human-infecting strain has a unique genetic profile different from similar species isolated from rodents so far.Conclusions/SignificanceLeptospira interrogans and Leptospira kirschneri were identified as the dominant Leptospira species causing human leptospirosis in Central Malaysia. The existence of novel clinically important ST 265 (infecting human), that is different from rodent L. interrogans strains cautions reservoir(s) of these Leptospira lineages are yet to be identified.
Serological and molecular prevalence of Leptospira infection in Rat populations in Kuala Lumpur
Leptospirosis is a communicable disease of humans and animals caused by infection with Leptospira spp. It is considered a re-emerging infection that reported by outbreaks in both developed and developing countries including the United States, countries of Latin America and Southeast Asia. Leptospirosis has been recorded as endemic in Malaysia since four decades. Several outbreaks has occurred exemplifying by the EcoChallenge Sabah 2000 competition, when caused in cases of people mortality and raised health authorities worried. Rats were recorded as the main source of infection since they maintain most of the leptospiral serovars. Leptospires colonized the renal tubules of the rat kidneys and then, rats disseminated the infection to the environment. Humans exposed to infection via direct or indirect contact with the urine or blood of infected animals. The objective of this study was to determine the serologic and molecular prevalence of Leptospira spp. circulating within rat communities in Kuala Lumpur. A total of 112 wild rats were trapped; R rattus (84%) and R norvegicus (16%) from four urban slums locations in Kuala Lumpur. Blood samples and kidneys of all animals were collected. Anti leptospiral antibodies were detected in sera by microscopic agglutination test (MAT). Kidney tissues were subjected to leptospiral DNA extraction and screened for Leptospira infection by multiplex PCR examined with two sets of primers; 16S rRNA and lipL32. Results: 63/112 (56%) sera were detected positive for anti leptospiral antibodies. Serovars; Bataviae and Javanica were recorded as recent infection. whereas, Icterohearragia, Canicola, Australis, Pomona and Andamana were reported as previous infection. mPCR assay confirmed the infection; 60 /112 (53.6%) of DNA samples were positive to 16S rRNA gene and 56 /112 (50%) of DNA were positive to lipL32 gene (the gene of virulence). Cohens’ K was carried for agreement between PCR-16S rRNA, PCR- lipL32 detection and serologic detection by MAT. The agreement was an almost perfect between mPCR-16S rRNA, lipL32 and MAT; K=1.000, 0.929 respectively with a significant differences P<0.001. PCR16S rRNA, lipL32 sensitivity was 100% in comparison with MAT. Whereas, PCR-16S rRNA, lipL32 specificity was 100% and 93.3% respectively in comparison with MAT. Categories such as rat species, gender and age were studied. The infection is more common among adult rats than sub-adults and this difference was statistically significant (χ2 = 6.748a ; P=0.009). whereas, species and gender were not statically