Baylisascaris procyonis is a raccoon roundworm that can infect other animals and rarely, humans.
Baylisascaris procyonis is a parasitic roundworm shed in racoon feces that can cause serious illness in humans. Infection with Baylisascaris occurs when humans ingest infectious eggs from raccoon feces or from food, water, objects, or soil contaminated with raccoon feces that contain infectious eggs.
A high percentage of raccoons are infected with Baylisascaris. These roundworms grow in the raccoons’ intestines and produce millions of eggs that are shed into the environment in the raccoons' feces. Eggs in raccoon feces are not immediately infectious. After two to four weeks in the environment, eggs become infectious; under the right conditions, eggs can survive in the soil for years.
Symptoms typically start 1-4 weeks after exposure but can sometimes take longer depending on the site of larval migration. Raccoon roundworm infection may cause:
- Nausea
- Fatigue
- Loss of coordination and muscle control
- Inability to focus attention
- Enlargement of the liver
- Blindness
- Coma
- Seizures
The infection can be fatal.
Raccoons become infected when they eat an infected animal (such as rodents, rabbits and birds) or ingest Baylisascaris eggs from the soil while foraging for food. Raccoons use communal latrines for defecation and have a habit of always defecating in the same place, resulting in large amounts of contaminated feces being present in an area.
Humans and animals, including pets, can become infected when they accidentally swallow infectious Baylisascaris eggs found in food, water, soil or other objects contaminated with raccoon feces. Young children or people with developmental disabilities who put hands and other objects into their mouths or have a habit of eating soil may be at increased risk for infection. Once inside the body, eggs hatch into larvae and cause disease when they travel through the liver, brain, spinal cord or other organs.
It is difficult to test for Baylisascaris infection - diagnosis is usually by process of eliminating other possibilities.
If you or your child have come into contact with raccoon feces and potentially ingested raccoon waste, see your doctor or health care provider and tell them about the exposure.
No medication is totally effective at treating Baylisascaris infection, but early detection and treatment with available medication may help.
If you see raccoons on your property or in the neighbourhood, check your property for evidence of raccoon latrines and dens. Raccoon latrines may be located at the base of trees, on flat surfaces such as logs, rocks, woodpiles or structures such as decks, patios, roofs and in attics or garages.
Ensure that children do not have access to areas where raccoons are or have been living. Wash your hands and your children’s hands thoroughly after playing outside. Discourage young children from putting their hands or fingers in their mouths.
Remove raccoon latrines and dens from your property. This is especially important if children are playing in the yard. If you need assistance with identification of latrines and dens, contact a local pest control company.
When cleaning up raccoon feces:
- Wear gloves. A face mask will prevent inadvertent ingestion of eggs from contaminated hands
- Avoid getting raccoon waste on your clothes
- Burn, bury or double bag the waste and put in the garbage
- Use boiling water to treat areas contaminated with waste such as decks and patios. Other disinfectants are not effective against Baylisascaris
- Wash your hands with liquid soap and water after removing gloves
To deter raccoons:
- Do not feed them
- Do not leave pet food outside
- Do not keep or treat raccoons as pets. Raccoons are wild animals
- Make bird feeders spill proof and ensure that raccoons cannot get to them. Store garbage in cans with lids that lock tightly. Cover sandboxes so they do not become raccoon latrines. Remove drinking water sources for raccoons such as ponds and other standing water
- Remove brush and other materials from your property where raccoons could make their dens
- Seal all access points to the house and other buildings, including basements and attics
