Angiostrongylus cantonensis: Agent of a Sometimes Fatal Globally Emerging Infectious Disease (Rat Lungworm Disease)

Angiostrongylus cantonensis, the rat lungworm, is a dangerous invasive species that is the agent of a potentially fatal globally emerging infectious disease. Humans are infected most commonly by ingestion, deliberately or inadvertently, of the parasite larvae in their intermediate snail hosts. The larvae make their way to the brain where they can cause severe neurological damage before eventually dying. Symptoms of the disease are diverse, making it difficult to diagnose. Treatment is primarily with corticosteroids to reduce inflammation, while treatment with anthelmintics to kill the worms remains controversial. There have been almost 3000 cases globally, the majority in southern China, but the parasite is spreading and now occurs much more widely. In the USA, almost all cases have been in Hawaii, but the parasite is also present in southeastern states. As the climate warms, this tropical/subtropical parasite is likely to spread further.