Health Hazard: Understanding “Rat Lungworm”

Source: Andrey Shupilo - 123RF

Australian rugby player, Sam Ballard, recounted a story, when, one night back in 2010, he accepted a dare to eat a slug (snail) while hanging out with friends after a game.

He didn’t become sick immediately but complained of serious pain in his legs in the days after. He fell into a coma for more than a year and developed a brain injury.

He had contracted eosinophilic meningoencephalitis, from which many people recover. Sam didn’t. Last week, eight years after he fell ill, he died.

The worm that infected Sam is usually found in rodents, but snails and slugs can also become infected when they eat rat feces.

According to the CDC, Angiostrongyliasis, also known as rat lungworm, is a disease that affects the brain and spinal cord. It is caused by a parasitic nematode (roundworm parasite) called Angiostrongylus cantonensis. The adult form of A. cantonensis is only found in rodents.

People can get infected by eating raw or undercooked snails or slugs that are infected with this parasite. In some cultures, snails are commonly eaten. Some children, in particular, have become infected by swallowing snails/slugs “on a dare. ” People also can get infected by accident, by eating raw produce (such as lettuce) that contains a small snail or slug or part of one.

Certain animals, such as freshwater shrimp, crabs, or frogs, have been found to be infected with larvae of the parasite. It is possible that eating undercooked or raw animals that are infected could result in people becoming infected, though the evidence for this is not as clear as for eating infected snails and slugs. Of note, fish do not spread this parasite.

The CDC advises to fully wash produce and stay away from eating raw or undercooked snails and slugs or other critters that could be exposed to the parasite.