Meeting Abstract

111.2  Tuesday, Jan. 7 08:15  Transmission of Raccoon Roundworm, Baylisascaris procyonis, through the deer mouse, Peromyscus maniculatus WEINSTEIN, S.B.; Univ. of California, Santa Barbara sara.weinstein@lifesci.ucsb.edu

Parasites frequently move through a specific sequence of hosts in order to complete their lifecycles. Unlike many other parasites with complex life cycles, Baylisascaris procyonis can infect its final host raccoon either directly, via eggs in the environment, or through predation by raccoons on infected intermediate hosts. Infective eggs are concentrated in the environment at raccoon latrines. We monitored these sites to identify species with increased exposure risk. The deer mouse, Peromyscus maniculatus was frequently observed foraging in raccoon feces. Seventy percent of mice trapped were infected with larval B. procyonis . In 40% of these infected mice larval worms were found in the brain, with a higher infection prevalence observed in larger animals. In other rodents migrating worms in the brain are debilitating or fatal, potentially increasing transmission to final hosts. However, the effects of B. procyonis on P. maniculatus are unknown and thus it is unclear whether the cerebral migrations undergone by the parasite are adaptive or incidental. We address this question by using a combination of work in the field and lab, and modeling, to quantify the relative contribution of trophic transmission to the population dynamics of B. procyonis .