Definition of Visceral larva migrans:

Visceral larva migrans is infection with certain parasites found in the intestines of dogs and cats.

Causes, incidence, and risk factors:

Visceral larva migrans is caused by worms (parasites) that infect the intestines of dogs and cats. The dog parasite is called Toxocara canis and the cat parasite is called Toxocara cati.

Eggs produced by these worms are in the feces of the infected animals. The feces mix with soil, allowing the infection to spread to humans. Humans may get sick if they eat food that grew in the infected soil. People can also become infected by eating raw liver.

Young children with pica (a disorder involving eating inedible things such as dirt and paint) are at highest risk, but this infection can also occur in adults. Outbreaks have occurred in the U.S. in children who play in areas with soil contaminated by dog or cat feces.

After a person swallows the contaminated soil, the worm eggs break open in the gastrointestinal tract and are carried throughout the body to various organs, such as the lungs, liver, and eyes. The brain, heart, and other organs can also be affected.