clove and Leptospirosis

Human activities can increase or decrease risks of acquiring a zoonotic disease, notably by affecting the composition and abundance of hosts. This study investigated the links between land use and infectious disease risk in northeast Madagascar, where human subsistence activities and population growth are encroaching on native habitats and the associated biota. We collected new data on pathogenic Leptospira, which are bacteria maintained in small mammal reservoirs. Transmission can occur through close contact, but most frequently through indirect contact with water contaminated by the urine of infected hosts. The probability of infection and prevalence was compared across a gradient of natural moist evergreen forest, nearby forest fragments, flooded rice and other types of agricultural fields, and in homes in a rural village. Using these data, we tested specific hypotheses for how land use alters ecological communities and influences disease transmission. The relative abundance and proportion of exotic species was highest in the anthropogenic habitats, while the relative abundance of native species was highest in the forested habitats. Prevalence of Leptospira was significantly higher in introduced compared to endemic species. Lastly, the probability of infection with Leptospira was highest in introduced small mammal species, and lower in forest fragments compared to other habitat types. Our results highlight how human land use affects the small mammal community composition and in turn disease dynamics. Introduced species likely transmit Leptospira to native species where they co-occur, and may displace the Leptospira species naturally occurring in Madagascar. The frequent spatial overlap of people and introduced species likely also has consequences for public health.

Topics: Animals; Ecology; Ecosystem; Forests; Humans; Introduced Species; Leptospira; Leptospirosis; Madagascar; Mammals; Prevalence; Zoonoses

In developing countries, estimates of the prevalence and diversity of Leptospira infections in livestock, an important but neglected zoonotic pathogen and cause of livestock productivity loss, are lacking. In Madagascar, abattoir sampling of cattle and pigs demonstrated a prevalence of infection of 20% in cattle and 5% in pigs by real-time PCR. In cattle, amplification and sequencing of the Leptospira-specific lfb1 gene revealed novel genotypes, mixed infections of two or more Leptospira species and evidence for potential transmission between small mammals and cattle. Sequencing of the secY gene demonstrated genetic similarities between Leptospira detected in Madagascar and, as yet, uncultured Leptospira strains identified in Tanzania, Reunion and Brazil. Detection of Leptospira DNA in the same animal was more likely in urine samples or pooled samples from four kidney lobes relative to samples collected from a single kidney lobe, suggesting an effect of sampling method on detection. In pigs, no molecular typing of positive samples was possible. Further research into the epidemiology of livestock leptospirosis in developing countries is needed to inform efforts to reduce human infections and to improve livestock productivity.

Topics: Abattoirs; Africa; Animals; Cattle; Cattle Diseases; Coinfection; Developing Countries; Disease Reservoirs; Genotype; Leptospira; Leptospirosis; Livestock; Madagascar; Phylogeny; Prevalence; Swine; Swine Diseases; Zoonoses

Leptospirosis is a neglected zoonotic bacterial disease caused by pathogenic

Topics: Animals; Cities; DNA, Bacterial; Kidney; Leptospira; Leptospira interrogans; Leptospirosis; Madagascar; Prevalence; Rodent Diseases; Rodentia

Leptospirosis is a zoonotic disease of global importance, especially in tropical countries. The current

Topics: Animals; Antibodies, Bacterial; Antigens, Bacterial; Cattle; Cattle Diseases; Leptospira; Leptospirosis; Madagascar; Seroepidemiologic Studies; Serogroup; Zoonoses

The occurrence of tick-borne relapsing fever and leptospirosis in humans in Madagascar remains unclear despite the presence of their potential vectors and reservoir hosts. We screened 255 Amblyomma variegatum ticks and 148 Rhipicephalus microplus ticks from Zebu cattle in Madagascar for Borrelia-specific DNA. Borrelia spp. DNA was detected in 21 Amblyomma variegatum ticks and 2 Rhipicephalus microplus ticks. One Borrelia found in one Rhipicephalus microplus showed close relationship to Borrelia theileri based on genetic distance and phylogenetic analyses on 16S rRNA and flaB sequences. The borreliae from Amblyomma variegatum could not be identified due to very low quantities of present DNA reflected by high cycle threshold values in real-time-PCR. It is uncertain whether these low numbers of Borrelia spp. are sufficient for transmission of infection from ticks to humans. In order to determine whether spirochaete infections are relevant in humans, blood samples of 1009 patients from the highlands of Madagascar with fever of unknown origin were screened for Borrelia spp. - and in addition for Leptospira spp. - by real-time PCR. No target DNA was detected, indicating a limited relevance of these pathogens for humans in the highlands of Madagascar.

Topics: Animals; Arachnid Vectors; Borrelia; Cattle; DNA, Bacterial; Humans; Ixodidae; Leptospira; Leptospirosis; Lyme Disease; Madagascar; Phylogeny; Real-Time Polymerase Chain Reaction; RNA, Ribosomal, 16S

Carnivores of Madagascar are at increased risk of extinction due to anthropogenic loss of habitat, hunting, and interactions with introduced carnivores. Interactions between introduced and native animals also present the potential for introduction of pathogens into new geographic areas or host species. Here, we provide serologic data regarding pathogen exposure of domestic and native carnivores from the Betampona Natural Reserve Landscape, a protected area in eastern Madagascar. For the Eupleridae, we found limited evidence of exposure to viruses from domestic animals but greater prevalence for Toxoplasma gondii (39%) and Leptospira interrogans (40%). We also evaluated the associations between the presence of antibodies to selected pathogens and the demographic and spatial variables. We showed that individual characteristics such as sex and species were associated with exposure to T. gondii but not to L. interrogans or canine parvovirus (CPV). Finally, we investigated the spatial structure of pathogen exposure in Betampona and found no evidence of spatial structuring, indicating the absence of hotspots and agent-free refugia for T. gondii, L. interrogans, and CPV in the protected area. Our results may be useful for assessing and monitoring disease risk and for formulating control strategies to minimize the negative impact of exotic species on the endemic carnivores of Madagascar.

Topics: Animals; Cat Diseases; Cats; Conservation of Natural Resources; Dog Diseases; Dogs; Eupleridae; Female; Leptospira interrogans; Leptospirosis; Madagascar; Male; Toxoplasmosis, Animal

We identified mixed infections of pathogenic Leptospira in small mammals across a landscape-scale study area in Madagascar by using primers targeting different Leptospira spp. Using targeted primers increased prevalence estimates and evidence for transmission between endemic and invasive hosts. Future studies should assess rodentborne transmission of Leptospira to humans.

Topics: Animals; Coinfection; Disease Reservoirs; History, 21st Century; Humans; Leptospira; Leptospirosis; Madagascar; Mice; Prevalence; Public Health Surveillance; Rats

Pathogenic Leptospira are the causative agents of leptospirosis, a disease of global concern with major impact in tropical regions. Despite the importance of this zoonosis for human health, the evolutionary and ecological drivers shaping bacterial communities in host reservoirs remain poorly investigated. Here, we describe Leptospira communities hosted by Malagasy bats, composed of mostly endemic species, in order to characterize host-pathogen associations and investigate their evolutionary histories. We screened 947 individual bats (representing 31 species, 18 genera and seven families) for Leptospira infection and subsequently genotyped positive samples using three different bacterial loci. Molecular identification showed that these Leptospira are notably diverse and include several distinct lineages mostly belonging to Leptospira borgpetersenii and L. kirschneri. The exploration of the most probable host-pathogen evolutionary scenarios suggests that bacterial genetic diversity results from a combination of events related to the ecology and the evolutionary history of their hosts. Importantly, based on the data set presented herein, the notable host-specificity we have uncovered, together with a lack of geographical structuration of bacterial genetic diversity, indicates that the Leptospira community at a given site depends on the co-occurring bat species assemblage. The implications of such tight host-specificity on the epidemiology of leptospirosis are discussed.

Topics: Animals; Biological Evolution; Chiroptera; Genetic Variation; Genotype; Host Specificity; Host-Pathogen Interactions; Humans; Leptospira; Leptospirosis; Madagascar; Molecular Sequence Data; Phylogeny

Leptospirosis is a bacterial zoonosis of major concern on tropical islands. Human populations on western Indian Ocean islands are strongly affected by the disease although each archipelago shows contrasting epidemiology. For instance, Mayotte, part of the Comoros Archipelago, differs from the other neighbouring islands by a high diversity of Leptospira species infecting humans that includes Leptospira mayottensis, a species thought to be unique to this island. Using bacterial culture, molecular detection and typing, the present study explored the wild and domestic local mammalian fauna for renal carriage of leptospires and addressed the genetic relationships of the infecting strains with local isolates obtained from acute human cases and with Leptospira strains hosted by mammal species endemic to nearby Madagascar. Tenrec (Tenrec ecaudatus, Family Tenrecidae), a terrestrial mammal introduced from Madagascar, is identified as a reservoir of L. mayottensis. All isolated L. mayottensis sequence types form a monophyletic clade that includes Leptospira strains infecting humans and tenrecs on Mayotte, as well as two other Malagasy endemic tenrecid species of the genus Microgale. The lower diversity of L. mayottensis in tenrecs from Mayotte, compared to that occurring in Madagascar, suggests that L. mayottensis has indeed a Malagasy origin. This study also showed that introduced rats (Rattus rattus) and dogs are probably the main reservoirs of Leptospira borgpetersenii and Leptospira kirschneri, both bacteria being prevalent in local clinical cases. Data emphasize the epidemiological link between the two neighbouring islands and the role of introduced small mammals in shaping the local epidemiology of leptospirosis.

Topics: Animals; Comoros; Disease Reservoirs; DNA, Bacterial; Eulipotyphla; Genotype; Humans; Introduced Species; Leptospira; Leptospirosis; Madagascar; Phylogeny; Zoonoses

Leptospirosis is a widespread but underreported cause of morbidity and mortality. It has rarely been reported in either humans or animals in Madagascar.. We conducted a cross-sectional survey of the inhabitants in Moramanga, Madagascar, in June 2011, to estimate the prevalence of human infection using the microscopic agglutination test (MAT). This activity was carried out as part of a workshop implemented by the Pasteur Institute of Madagascar, focusing on surveillance with a one week field study and targeting the health staff of the district level.. In total, we sampled 678 inhabitants from 263 households. The sex ratio (M/F) was 0.65 and the mean age 26.7 years. We obtained a value of 2.9% for the first recorded seroprevalence of this disease in the human community of Moramanga. Questionnaire responses revealed frequent contacts between humans and rodents in Moramanga. However, activities involving cattle were identified as a risk factor significantly associated with seropositivity (OR=3).. Leptospirosis remains a neglected disease in Madagascar. This study highlights the need to quantify the public health impact of this neglected disease in a more large scale, in all the country and to establish point-of-care laboratories in remote areas.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Agglutination Tests; Animals; Animals, Domestic; Antibodies, Bacterial; Cattle; Cattle Diseases; Child; Child, Preschool; Cross-Sectional Studies; Disease Reservoirs; Female; Housing; Humans; Immunologic Surveillance; Infant; Leptospira; Leptospirosis; Madagascar; Male; Middle Aged; Poverty; Prevalence; Rats; Rodent Diseases; Sampling Studies; Suburban Health; Surveys and Questionnaires; Young Adult; Zoonoses

Leptospirosis has long been a major public health concern in the southwestern Indian Ocean. However, in Madagascar, only a few, old studies have provided indirect serological evidence of the disease in humans or animals.. We conducted a large animal study focusing on small-mammal populations. Five field trapping surveys were carried out at five sites, from April 2008 to August 2009. Captures consisted of Rattus norvegicus (35.8%), R. rattus (35.1%), Mus musculus (20.5%) and Suncus murinus (8.6%). We used microbiological culture, serodiagnosis tests (MAT) and real-time PCR to assess Leptospira infection. Leptospira carriage was detected by PCR in 91 (33.9%) of the 268 small mammals, by MAT in 17 of the 151 (11.3%) animals for which serum samples were available and by culture in 9 of the 268 animals (3.3%). Rates of infection based on positive PCR results were significantly higher in Moramanga (54%), Toliara (48%) and Mahajanga (47.4%) than in Antsiranana (8.5%) and Toamasina (14%) (p = 0.001). The prevalence of Leptospira carriage was significantly higher in R. norvegicus (48.9%), S. murinus (43.5%) and R. rattus (30.8%) than in M. musculus (9.1%) (p<0.001). The MAT detected antibodies against the serogroups Canicola and Icterohaemorrhagiae. Isolates were characterized by serology, secY sequence-based phylogeny, partial sequencing of rrs, multi-locus VNTR analysis and pulsed field gel electrophoresis. The 10 isolates obtained from nine rats were all identified as species L. interrogans serogroup Canicola serovar Kuwait and all had identical partial rrs and secY sequences.. We present here the first direct evidence of widespread leptospiral carriage in small mammals in Madagascar. Our results strongly suggest a high level of environmental contamination, consistent with probable transmission of the infection to humans. This first isolation of pathogenic Leptospira strains in this country may significantly improve the detection of specific antibodies in human cases.

Topics: Animals; Bacterial Proteins; Disease Reservoirs; DNA, Bacterial; Eulipotyphla; Geography; Humans; Kidney; Leptospira; Leptospirosis; Madagascar; Mammals; Mice; Molecular Sequence Data; Phylogeny; Rats; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Species Specificity

A polymerase chain reaction (PCR) technique was used for detection of the Leptospira interrogans rrs gene in kidney tissue from 115 rats, 50 zebu cattles and 13 pigs in an attempt to identify a possible animal reservoir of leptospirosis in Madagascar. In addition, serological testing of 105 individuals in close contact with animals was carried out. The PCR analysis was negative for all the samples tested and only one person was found seropositive at a low titer. The findings suggest that leptospirosis, if prevalent in Madagascar, is likely rare.

Topics: Animals; Bacteriological Techniques; Cattle; Cattle Diseases; Disease Reservoirs; Disease Vectors; DNA, Bacterial; Humans; Leptospira interrogans; Leptospirosis; Madagascar; Polymerase Chain Reaction; Population Surveillance; Prevalence; Rats; Rodent Diseases; Sensitivity and Specificity; Swine; Swine Diseases; Zoonoses

Topics: Agglutination Tests; Animals; Antibodies, Bacterial; Humans; Leptospira; Leptospirosis; Madagascar; Rodentia; Species Specificity; Zoonoses