Baylisascaris procyonis (Chromadorea Ascarididae): Case Study of the Little-Known Human Health Threat That Is Literally in Your Backyard

Baylisascariasis is a debilitating and potentially lethal zoonotic disease caused by a nematode parasite that has a worldwide distribution. Baylisascaris spp. are carried by a variety of mammalian definitive hosts, and their larvae can infect a large diversity of paratenic hosts including birds and mammals, and even humans. Herein, the potential exposure risk of this zoonotic parasite is demonstrated through the study of a suburban American community with a population of Baylisascaris procyonis—infected raccoons (Procyon lotor) as a case study for any location with Baylisascaris spp., definitive hosts, and proximity to humans. Soil from 100 properties within neighborhoods of southern Corpus Christi, TX, USA, was surveyed to determine if viable B. procyonis eggs were present. In total, 27% of the residential properties were contaminated. Positive soil samples, on average, contained 31,287 B. procyonis eggs/gram of soil; of these samples, 92% of the B. procyonis eggs had motile larvae. Sites with contaminated soils appeared random within residential properties; frequency of contaminated sites was similar between known raccoon defecation sites and random sites. Suggestions for the reduction in risks of exposure to this potentially debilitating parasite are offered to residents of Baylisascaris-contaminated properties.