1Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA, USA; 2Southeastern Cooperative Wildlife Disease Study, Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA, USA; 3Environmental Health Science, University of Georgia, Athens, GA, USA; 4Poultry Diagnostic and Research Center, Department of Population Health, University of Georgia, Athens, GA, USA; 5The Athens Diagnostic Laboratory, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
Due to the increased morbidity and mortality associated with salmonellosis in children, most studies have focused on reptiles, where there is a clear relationship between ownership of certain pets and infection. Surveys have documented the presence of Salmonella in a variety of wildlife species;1-6 however, their role as reservoirs remains unknown. We investigated Salmonella prevalence and the geographic/temporal variation of Salmonella serovars from water and mesomammals in two watersheds in Georgia, one of which (South) has a history of high cases of human salmonellosis. Monthly water and quarterly mammal samples were collected from 3 stations in each watershed for 12 mo. The prevalence of Salmonella recovered from surface waters from the Southern stations was 48%, while the prevalence in the North was 60%. The prevalence of infection in opossums was 41% (95% CI: 0.29, 0.55; n=65) and 61% (95% CI: 0.47, 0.73; n=63) in the Northern and Southern watersheds respectively; and that of raccoons was 43% (95% CI: 0.24, 0.62; n=38) and 50% (95% CI: 0.31, 0.69; n=25). In both species, the highest prevalence occurred during the summer months (p=0.012). Of particular significance, the Salmonella serotypes recovered from raccoons and opossums were diverse (n=13), but their Pulse Field Gel Electrophoresis (PFGE) patterns matched those serotypes recovered from water and from human cases in the CDC PulseNet database.7 Due to readily-accessible food and habitat, anthropogenic areas, including zoos, often attract raccoons and opossums, which we consider to be asymptomatic transporters of environmental Salmonella serotypes responsible for human salmonellosis cases.
This work was funded by an NIH R15 grant. We thank all the undergraduate and veterinary students who participated in the field work for this project.
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