Distribution and prevalence of Babesia spp. in raccoons (Procyon lotor) in the United States and Canada

Babesia spp. are tick-borne intraerythrocytic protozoans, many of which have veterinary or medical importance. Two morphologically similar species, Babesia lotori and Babesia microti-like, occur in raccoons (Procyon lotor).... [ view full abstract ]

Babesia spp. are tick-borne intraerythrocytic protozoans, many of which have veterinary or medical importance. Two morphologically similar species, Babesia lotori and Babesia microti-like, occur in raccoons (Procyon lotor). One study found both species were common in raccoons in North Carolina (~90%). However, little is known of the distribution and prevalence of these parasites in raccoons. Historically, raccoons were the only known host for these two Babesia spp.; however, recently maned wolves (Chrysocyon brachyurus) in several zoos in the Midwestern USA have been diagnosed with severe or fatal babesiosis caused by B. lotori. To obtain knowledge on the distribution and prevalence of these Babesia spp. across a wide geographic range, blood and spleen samples were opportunistically obtained from raccoons from the USA (Georgia, Florida, Kentucky, West Virginia, Pennsylvania, Kansas, Minnesota, California) and Canada (Nova Scotia). Samples were tested using species-specific PCR assays. For B. lotori, prevalence was highest in the southeastern states (67-89% [113/155]). The prevalence in Nova Scotia (0% [0/80]) was significantly lower than other sites other than Pennsylvania (5% [1/22]) and California (27% [9/33]). The B. microti-like sp. was detected at all sites; in general, prevalence was highest in the Southeast (67-100% [129/155]) and lowest (6% [5/80]) in Nova Scotia. Coinfections were common. These data indicate there is spatial variability in the prevalence of these two Babesia spp. Currently there is no known vector for either Babesia spp., thus these data may assist in determining potential vector(s). Susceptible species, such as maned wolves, are at a greater risk of infection with B. lotori in southeastern states.