The Ecology and Epidemiology of the Raccoon Roundworm in Baskett Wildlife Area [abstract]

Abstract

The raccoon (Procyon lotor) is the carrier or final host of the raccoon roundworm (Baylisascaris procyonis), which is an endoparisitic nematode. Raccoons ingest the nematode eggs that hatch and develop into adults in the raccoon's intestines. In previous research, raccoons exhibit a latrining behavior whereby they continually return to defecate in a single communal area, known as latrines. Latrines serve as a long-term point source for contact with the nematode eggs that lead to the infection of other species. When the nematode infests an intermediate or accidental host, the larvae do not live in the intestine, but instead travel into other tissues, including the central nervous system; extensive visceral, ocular, and neural tissue damage, as well as, behavioral changes and death in wild/domestic mammals (including humans) and birds can occur. In this study, we addressed three issues related to the ecology and epidemiology of raccoon roundworm, a parasite of concern for wildlife conservation and human health. (1) We examined the prevalence of roundworm in a raccoon population and latrines located in the Baskett Wildlife Area, which is a local forested ecosystem. Prevalence of this parasite is poorly understood in forested ecosystems. (2) We used a telemetry-based approach, 21 plots, and 5 - 500-1,000 meter line transects in known and unknown raccoon activity to determine how latrines are formed and maintained. (3) We also determined existence of communal denning to help understand the ecology and transmission of the roundworm. We found a latrine density of 0-28 latrines/ha with each latrine having 1-10 feces. Initial results indicate there is a lower prevalence rate of the roundworm in raccoons and latrines in Baskett Wildlife Area compared to previous research. Evidence shows very few instances of latrines being formed in the same place more than once; there was no evidence of communal denning.