Prevalence of Trypanosoma cruzi Antibodies in Wild Pigs (Sus scrofa) in the USA.

Wild pig (Sus scrofa) populations are expanding across the USA, raising concerns about the ecologic impacts and role as reservoirs for pathogens of significance to human and animal health. Trypanosoma cruzi, the causative agent of Chagas disease, is a recognized risk for humans and domestic dogs in the southern USA. Common wildlife reservoirs of T. cruzi include rodents (e.g., Neotoma spp.), raccoons (Procyon lotor), and Virginia opossums (Didelphus virginiana); however, there have been reports of T. cruzi infection in suids, including a domestic pig (Sus scrofa domesticus) in Mexico and three wild pigs in Texas, USA. Our study aimed to better understand the prevalence and distribution of T. cruzi antibodies in wild pigs in the USA. We collected 1,093 serum samples from wild pigs across 12 states in the southern, midwestern, and western regions of the USA, all of which have populations of T. cruzi triatomine vectors. We tested sera for antibodies against T. cruzi using an indirect ELISA and detected an overall apparent prevalence of 14.6% (160/1,093; 95% confidence interval, 12.6-16.9%). Pig sex, age class, month of sampling, and region were not significantly associated with seroprevalence; however, state of origin explained some variation in the data. We demonstrated that wild pigs in the USA were exposed to T. cruzi, highlighting the need for further research elucidating their role in T. cruzi transmission.