Exploring the Terrestrial Component of Potential Land-Sea Transmission of Toxoplasma gondii in Coastal California
American Association of Zoo Veterinarians Conference 2007
Elizabeth VanWormer1, DVM; Daniel Rejmanek2; Patricia Conrad2, DVM, PhD; Melissa Miller3, DVM, PhD; Ann Melli2; Richard Ostfeld4, PhD; Paul Crosbie5, PhD; Jonna Mazet1, DVM, MPVM, PhD
1Wildlife Health Center, School of Veterinary Medicine, University of California-Davis, Davis, CA, USA; 2Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California-Davis, Davis, CA, USA; 3California Department of Fish and Game, Marine Wildlife Veterinary Care and Research Center, Santa Cruz, CA, USA; 4Institute of Ecosystem Studies, Millbrook, NY, USA; 5Department of Biology, California State University, Fresno, CA, USA
Toxoplasma gondii, a globally distributed protozoan parasite, infects a wide range of birds and mammals, including humans. Identified as a significant cause of mortality in the threatened California Southern sea otter population, T. gondii also presents an important public health concern. The terrestrial shedding of T. gondii by wild and domestic felids and studies linking otter infection to freshwater run-off suggest potential land to sea pathogen transmission along California’s central coast. High risk sites for marine exposure to T. gondii have been identified, but parasite burden in the terrestrial environment is not well characterized. Current limitations of molecular tests prevent direct measurement of parasite load in the environment. Our collaborative, interdisciplinary research approach, using current epidemiologic and molecular techniques, is addressing the hypothesis that terrestrial environmental contamination with oocysts and risk of exposure to T. gondii can be predicted based on the prevalence of infection in domestic felid, wild carnivore and wild rodent populations. Identifying areas of increased terrestrial T. gondii exposure and risk factors for environmental parasite accumulation will facilitate the identification and implementation of future management strategies to reduce the environmental exposure of humans and sensitive wildlife species to this pathogen.