TRANSMISSION MODE

The life cycle of Anisakis begins in the feces (poo) of an infected sea mammal. The feces containAnisakiseggs which immediately hatch in the sea water. The tiny larvae are eaten (but not killed) by small crustaceans which are eaten by fish (or squid). The larvae penetrate the gut and encyst in muscles or other parts of the fish. Finally a marine mammal eats the infected fish. The larvae excyst in the bowel and find another larvae of the opposite sex to mate with. (In humans the larvae stay in the stomach never reaching adulthood nor the small intestine.) The life cycle is completed, when a female lays eggs which exit the body in the feces..Human infection is a dead end in the parasite’s life cycle. The worms are usually eliminated expelled from the intestines within 3 weeks of infection.

CHARACTERISTICS

Anisakisis is caused by ingesting a larval stage of a marine roundworm in undercooked or raw marine fish.  Initial symptoms begin within hours of eating the seafood.  These include severe abdominal pain, vomiting, and nausea.  Because the worms initially remain in the upper digestive tract, the worm can be “coughed up.”  If the worms pass into the intestines they can cause symptoms resembling Crohn’s Disease 1-2 weeks after infection.  Diagnosis and treatment is done by removing larvae visualized during gastroscopic examination.