Raccoon Roundworm

Raccoon roundworm, known scientifically as Baylisascaris procyonis, is a parasitic infection that has gained some attention in the U.S. as a source of human disease. Although this parasite is relatively harmless to the raccoon, serious illness can occur in humans when infective eggs are accidentally ingested. Ingested eggs hatch as larvae in the small intestine, penetrate the intestinal wall and migrate to other organs such as the liver, lungs, and brain through the circulatory system. If the larvae migrate to the eye, brain, or spinal cord, there can be severe and irreversible damage including blindness, paralysis, and death.

Fortunately, the incidence of human illness in the U.S. is low (less than 30 cases have been reported). Young children are the most likely individuals to become infected as they commonly put dirt and other objects into their mouths. The CDC receives over 4,000 requests annually for laboratory testing for this parasite.

The Vector-Borne Disease Prevention Program (VBDPP) staff have determined that the raccoon roundworm parasite is present in raccoons living in the Truckee Meadows (see surveillance activities). The staff is available for consultation and education regarding raccoon problems at 328-2434.

Racoon Roundworm Brochure