Pathogen infection and exposure, and ectoparasites of the federally endangered Amargosa vole (Microtus californicus scirpensis), California, USA.

Abstract We surveyed pathogens and ectoparasites among federally endangered Amargosa voles (Microtus californicus scirpensis) and sympatric rodents in Tecopa Hot Springs, Inyo County, California, December 2011-November 2012. We aimed to assess disease and detect possible spillover from or connectivity with other hosts within and outside the Amargosa ecosystem. We assessed 71 individual voles and 38 individual sympatric rodents for current infection with seven vector-borne zoonotic pathogens and past exposure to five pathogens. Thirteen percent of Amargosa voles were PCR positive for Toxoplasma gondii, a zoonotic protozoan that may alter host behavior or cause mortality. Additionally, we found antibodies against Borrelia burgdorferi sensu lato (SL) spp. in 21% of voles, against Anaplasma phagocytophilum in 2.6%, Rickettsia spp. in 13%, relapsing fever Borrelia (3.9%), and T. gondii (7.9%). Sympatric rodents also had active infections with Borrelia SL spp. (15%). Of the ectoparasites collected, the tick Ixodes minor is of particular interest because the study area is well outside of the species' reported range and because I. minor ticks infest migratory birds as well as rodents, showing a potential mechanism for pathogens to be imported from outside the Amargosa ecosystem.