A study of the raccoon roundworm in Ontario. It’s a trap!
Research is currently underway at the University of Guelph to investigate the raccoon intestinal parasite Baylisascaris procyonis. A component of this research is focused on further understanding the transmission of this parasite between its definitive host, the raccoon and paratenic hosts, which are infected with the larval stage of the parasite.
Image 1: Virginia Opossum visiting latrine site at night.
A wide variety of animals, including humans, can be infected with the larval stage of the parasite. Humans and other animals can become infected with this parasite by ingesting infective eggs that are shed by raccoons in their feces. These eggs are resistant to environmental degradation and can persist in the environment for years. Raccoons can become infected with the roundworm by ingesting infective eggs or by ingesting animals infected with the larval stage of the parasite.
Image 2: Two raccoons visiting latrine site at night.
Raccoons are known to defecate in communal sites known as latrines. Commonly used sites include sheds, attics, the base of trees, flat elevated surfaces, rocks and tree stumps. These latrines can be a significant source of exposure to B. procyonis in humans and animals. To investigate the transmission of B. procyonis between raccoons and paratenic hosts, researchers are utilizing motion sensing camera traps. In collaboration with the University of Guelph Arboretum, these camera traps are being strategically placed at known raccoon latrines to capture which animals are visiting these sites. Preliminary trials have already captured numerous species visiting these sites, including the eastern cottontail, Virginia opossum, eastern chipmunk, and the eastern gray squirrel. A better understanding of the relationship of this parasite and its hosts will allow us to better educate the public and make decisions to help prevent exposure to this parasite in the future.
Image 3: Eastern cottontail visiting latrine site during the day.
For more information on Baylisascaris procyonis exposure in humans please visit: Centers for Disease Control and Prevention
