Angiostrongylus Cantonensis Infection

Angiostrongylus Cantonensis is a parasite, or worm, found in rats. Infected rats pass immature forms of the worm in their feces. Snails and slugs get infected by eating infected rat feces. The young forms of the parasite mature in snails and slugs but do not become adult worms. The life cycle of the parasite comes full circle when rats eat infected snails or slugs and the immature parasites become adult worms. Most of the known cases of infection in people have occurred in Southeast Asia and the Pacific Islands. Some cases have occurred in other areas, such as in the Caribbean.

People can get infected under unusual circumstances. However, even if infected, most people recover fully without treatment.


  • Eating raw or undercooked snails or slugs that are infected with the parasite. In some cultures, snails are commonly eaten.

  • Children can be infected by swallowing snails "on a dare."

  • Accidentally eating raw produce that contains a small snail or slug or part of one.

  • Eating raw or undercooked freshwater prawns, crabs, or frogs.


  • Some infected people do not have any symptoms, or have only mild symptoms that do not last very long.

  • Sometimes the infection causes a rare type of meningitis (eosinophilic meningitis).

  • The symptoms can include headache, stiff neck, tingling, or painful feelings in the skin, low-grade fever, nausea, and vomiting.


Your caregiver will ask you about any symptoms, exposures to snails and slugs, and foreign travel you've had. You might be given routine blood tests, special blood tests to look for an immune response to the parasite, and tests for meningitis.


  • Usually not. The parasite dies over time, even without treatment. Even people who develop eosinophilic meningitis usually do not need antibiotics.

  • Sometimes the symptoms of the infection last for several weeks or months, while the body's immune system responds to the dying parasites.

  • The most common types of treatment are for the symptoms of the infection (such as pain medication for headache) rather than for the infection itself.

  • Patients with severe cases of meningitis may benefit from some other types of treatment.


  • Do not eat raw or undercooked snails or slugs.

  • If you handle snails or slugs, wear gloves and wash your hands.

  • Always remember to thoroughly wash fresh produce.