Baylisascaris infection

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Baylisascaris infection is brought about by a roundworm present in raccoons. This roundworm is capable of infecting humans as well as other animals including dogs. Infections in humans is rare but can become severe if the parasites invade the eye, other organs or the brain.

Raccoons are the primary host of the Baylisascaris procyonis roundworm. Even though raccoons are the main host, other animals can still become infected. Small mammals such as rabbits and rodents and birds are susceptible to the parasite.

Humans become infected by ingesting the fertile eggs. Those who are exposed to environments in which raccoons are present are at risk. Young children or developmentally incapacitated individuals face the peak risk for the infection since they are more likely to place soiled fingers, soil or objects into their mouths.

What are the indications?

Baylisascaris infection
The ingestion of a few eggs can cause few or no symptoms while ingesting several eggs can lead to serious symptoms.

Those who become infected occur upon accidental ingestion of the eggs in water, soil or on objects that has been contaminated by raccoon feces. The infection is not spread from one individual to another. If a human ingests these eggs, they emerge into larvae inside the intestines and move around the body, involving the muscles and organs.

Depending on where the larvae migrates, the infection can involve the brain and spinal cord, eyes and/or other organs.

The indications depend on the number of eggs ingested and the body part where the larvae migrates. The ingestion of a few eggs can cause few or no symptoms while ingesting several eggs can lead to serious symptoms. The indications of infection can take up to a week or so to develop and includes the following:

  • Nausea
  • Enlargement of the liver
  • Tiredness
  • Loss of coordination
  • Loss of muscular control
  • Loss of attention to the surroundings and people
  • Blindness
  • Coma


There are no available drugs that are proven fully effective for managing Baylisascaris infection. In some cases, albendazole which is a broad spectrum anthelmintic has been used.

Prompt treatment can minimize significant impairment caused by the infection. If an individual is suspected to ingested the raccoon feces, immediate medical care is vital.


Baylisascaris infection can be averted by avoiding exposure to raccoons and the feces. Proper hand washing of hands must be observed after spending time outdoors.

It is not advisable to feed or take in wild animals especially raccoons as pets. Remember that the infection rarely results to symptoms among raccoons. You cannot determine if it is diseased by monitoring its behavior. The roundworm eggs that are passed in the feces of infected raccoons are only seen using a microscope.

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