Slugs and snails aren't the only animals that can cause rat lungworm disease in humans

In addition to slugs and snails, more than a dozen animals cause rat lungworm disease in people around the world, a review of decades of research shows

Researchers from the University of Hawaii Mānoa and University of London (UK) combed through nearly 140 scientific studies published between 1962 and 2022 and found 32 species of freshwater prawns/shrimp, crayfish, crabs, flatworms, fish, sea snakes, frogs, Toads, lizards, centipedes, cattle, pigs and snails can act as rat lungworm parasites (abstract cantonensis).

This work is a master's thesis study by first author Helena Turck, as part of the postgraduate project One Health, run jointly by the Royal Veterinary College of the University of London, UK, and the London School of Hygiene and Tropical Medicine

Rat lungworms have a complex life cycle, Cowie explained, with slugs and snails being the so-called "intermediate" hosts, and rats being the "ultimate" hosts for the worms to mature and reproduce

human, accidental host

"But people can also become infected if they eat so-called paratenic hosts, also known as vector hosts," said Cowie, a research professor at SOEST's Pacific Centre for Bioscience Research

At this time, they move, eat and grow in the human brain

"It's important to know that not only snails and slugs can transmit rat lung worm parasites to humans, but other animals -- that is, the parental hosts -- can do the same," Cowie said

Mouse lung worm disease worldwide

Rat lungworm disease is currently mainly confined to tropical and subtropical regions, especially parts of South and Southeast Asia, which may be its origin, southern China, Taiwan, southern Japan, various Pacific islands and archipelagos, and more recently Brazil, the Caribbean Islands and Australia

Hawaii is the global epicentre of rat lungworm disease, and in fact, University of Hawaii and U.

"Hawaiian has several species that can act as vectors (hosts), including flatworms, centipedes, coqui frogs and cane toads," Cowie said

Domesticated animals, especially dogs and horses, can also become infected with the rat lung worm parasite, including in Hawaii, possibly mainly from accidental or deliberate eating of snails or slugs

infection prevention

There are several things people can do to prevent infection with rat lungworm

"It's critical to understand which species may harbor parasites, both in Hawaii and more broadly," Cowie said