Determining the prevalence of raccoon roundworm (Baylisascaris procyonis) in New Brunswick, Canada

Abstract

The raccoon roundworm (Baylisascaris procyonis) is an intestinal nematode mainly found within its primary definitive host of raccoons (Procyon lotor). Contraction of the raccoon roundworm by humans can cause the development of Baylisascariasis, a potentially deadly disease that can also cause blindness and a variety of other negative health effects. With the largest risk group consisting of adolescents, and the lack of extensive research on the parasite within the province of New Brunswick, further understanding of the raccoon roundworm and the ecological factors influencing its prevalence is of great epidemiological importance. This study sampled feces from 8 raccoon latrines across the province to determine the prevalence of the raccoon roundworm in New Brunswick for the first time in 10 years. These results were correlated to ecological factors including sightings of domestic animals and of wildlife (excluding raccoons) determined by the establishment of night-vision camera traps across 28 locations around the region of south-eastern New Brunswick for 4-months in 2021. Fecal floatation was performed to isolate potential roundworm eggs for subsequent microscopy and DNA analyses of samples. Raccoon roundworm eggs were microscopically identified across 6 latrine locations, while 3 locations were molecularly confirmed via PCR and genetic sequencing. Fecal samples from latrines with lower roundworm EPG counts ranged from 0 – 8.3, and would be undetectable by PCR analysis, while latrines with higher roundworm EPG counts range from 76.2 – 159.6 (overall median = 5.40 EPG, IQR = 17.6). Increased incidence of Baylisascaris procyonis positive latrine samples were correlated to increased sightings of domestic animals, which may present a possible source of greater risk to humans inhabiting regions with this factor.