Baylisascaris procyonis is a large roundworm that lives
in the intestines of raccoons.
Adult worms can
measure 5 to 8 inches long and 1/2 inch wide. The adult worms shed millions of
microscopic eggs that are passed in the raccoon's
feces. The worm does not harm the raccoon, but can
cause serious illness in humans.
Loss of muscle control
Baylisascaris procyonis is increasingly being
recognized as a cause of severe human disease.
How is Baylisascaris spread?
People become infected with Baylisascaris when they
ingest eggs in soil, water, or on objects that have
been contaminated with raccoon feces.
particularly toddlers, are at higher risk of exposure
as they may put contaminated fingers, soil or objects
in their mouth.
These eggs are resistant to most environmental conditions, and with adequate water,
can survive from months to years. When humans
ingest these eggs, they hatch into larvae in the
person's intestine and migrate throughout the body,
affecting the organs and muscles.
How soon after exposure do symptoms
Symptoms of Baylisascariasis generally appear one
to three weeks after ingestion, although they may
take as long as two months to develop.
of symptoms depends on the amount of eggs
ingested. The infective dose of Baylisascaris is
estimated to be 5,000 eggs or less.
How is Baylisascariasis diagnosed?
Baylisascariasis can be diagnosed in humans based
on observation of the larvae in the skin or eye
lesions. Infection can also be diagnosed by ruling out other infections that cause similar symptoms.
1980, 11 human cases of Baylisascariasis have been
reported in the United States, four of them fatal.
What is the treatment for Baylisascariasis infection?
Currently there are no drugs that can effectively kill
the migrating larvae in the body. Laser surgery has
been successful in killing larvae present in the retina of the eye but the damage caused by the migrating
larvae is irreversible.
How can Baylisascariasis be prevented?
Controlling Baylisascaris procyonis requires avoiding
contact with raccoons and areas inhabited by
Discourage raccoons from visiting your home or yard by eliminating access to food sources like pet food, garbage cans and bird feeders.
Raccoons may nest in wood piles, attics, chimneys, sheds and barn lofts.
Raccoons should not be kept as
pets; they are dangerous wild animals that can carry
other diseases such as rabies and plague.
How should I clean up raccoon feces?
Materials contaminated with raccoon feces should be
carefully removed and buried, burned, or bagged
and disposed of in a landfill.
Wear disposable gloves, boots and a dust mask when disposing of
Contaminated surfaces can
be decontaminated by flaming with a propane torch
(concrete and other non flammable surfaces) or with
Where can I get more information?
Contact your doctor or the Southern Nevada Health District, Office of Epidemiology at (702) 759-1300.