Nematodes of rats of the genus Angiostrongylus cause two distinct syndromes in humans. Angiostrongylus cantonensis, the rat lungworm, causes eosinophilic meningoencephalitis, primarily in Southeast Asia and some Pacific islands, but with multiple recent reports also from the Americas, Hawaii (82 reported cases in 2007–17), and Australia. In one study, A cantonensis was responsible for 67% of evaluable cases of eosinophilic meningitis in Vietnam. Angiostrongylus costaricensis causes gastrointestinal inflammation. In both diseases, human infection follows ingestion of larvae within slugs or snails (and also crabs, prawns, or centipedes for A cantonensis) or on material, such as salads, contaminated by these organisms. Since the parasites are not in their natural hosts, they cannot complete their life cycles, but they can cause disease after migrating to the brain or gastrointestinal tract. A cantonensis can also migrate from the brain to the pulmonary arteries.