Prevalence of Baylisascaris procyonis in raccoons (Procyon lotor) in Portland, Oregon, USA.

We investigated the prevalence of Baylisascaris procyonis in raccoons living in the metropolitan area of Portland, Oregon, USA, in order to assess the potential public health risk involved in the transmission of B. procyonis to humans and companion animals. Sixty-nine euthanized raccoons were collected from Portland wildlife-control agencies. Infection with B. procyonis was determined through the harvesting of adult worms from raccoon intestines during necropsy and by fecal analysis using modified double-centrifugation technique with a sugar-flotation solution. Fifty-eight percent of sampled raccoons were found to be infected with B. procyonis. Juveniles represented a greater percentage (64%) of raccoons captured by wildlife-control agents and were found to have the highest prevalence (70%) and heavier adult worm burdens (mean=35 worms). No gender bias was evident. This is one of the few studies of Baylisascaris prevalence in the Pacific Northwest, and it demonstrates that there is a high prevalence of B. procyonis in raccoons inhabiting the Portland area. This factor should be considered in raccoon relocation and management. The data also suggest that juvenile raccoons are the major potential source of B. procyonis contamination in the Portland community and may merit special attention to minimize their interaction with humans.