Slugs, snails usually are not alone in inflicting rat lungworm illness in people

A overview of a long time of analysis revealed greater than a dozen sorts of animals along with slugs and snails have precipitated rat lungworm illness in individuals all over the world.

Researchers from the University of Hawai’i at Mānoa and the University of London (UK) combed by means of almost 140 scientific research printed between 1962 and 2022 and located 32 species of freshwater prawns/shrimp, crayfish, crabs, flatworms, fish, sea snakes, frogs, toads, lizards, centipedes, cattle, pigs, and snails can act as carriers of the rat lungworm parasite (Angiostrongylus cantonensis). Of these, at the least 13 species of prawns/shrimp, crabs, flatworms, fish, frogs, toads, lizards, and centipedes have been related to inflicting rat lungworm illness in people.

This work was the grasp’s diploma thesis analysis of the primary writer, Helena Turck, as a part of a graduate program in One Health collectively run by the Royal Veterinary College and the London School of Hygiene and Tropical Medicine, each a part of the University of London, UK. Robert Cowie, senior writer on the examine and school member within the UH Mānoa School of Ocean and Earth Science and Technology (SOEST), supervised Turck’s analysis remotely in the course of the pandemic and co-authored the brand new publication. Professor Mark Fox of the Royal Veterinary College can also be a co-author of the examine.

Cowie defined that the rat lungworm has a posh life cycle that includes slugs and snails as so-called “intermediate” hosts and rats as “definitive” hosts through which the worms attain maturity and reproduce. Rats turn out to be contaminated once they eat an contaminated snail or slug. People additionally turn out to be contaminated once they eat an contaminated snail or slug, and this may result in critical sickness and infrequently demise.

Humans, unintentional hosts

“But people can also get infected if they eat so-called paratenic hosts, which are also known as carrier hosts,” mentioned Cowie, who’s a analysis professor within the Pacific Biosciences Research Center at SOEST. “These are animals that become infected by eating infected snails or slugs, but in which the worms cannot develop to maturity as they do in a rat. However, in such hosts the worms become dormant, but still infective. And if one of these hosts, or part of one, is then eaten raw by a person—an accidental host—development can continue, but only up to a point.”

That level is when they’re within the individual’s mind, the place they’re shifting round, feeding, and rising. But then the worms die. The harm to the mind and the large irritation that outcomes once they die is primarily what causes the signs of rat lungworm illness.

“It is important to know not only that snails and slugs can transmit rat lungworm parasites to humans but also which other animals—which paratenic hosts—can also do so,” Cowie mentioned. “So the goal of the study, was to pull all the information on paratenic hosts and their role in transmission of rat lungworm disease, previously scattered in diverse publications and obscure reports, together into one place and develop a global understanding of their diversity and role in disease transmission.”

Rat lungworm illness across the globe

Rat lungworm illness is at current confined largely to the tropics and subtropics, notably components of South and Southeast Asia, the place it most likely originated, southern China, Taiwan, southern Japan, numerous Pacific islands and archipelagos, and extra lately Brazil, Caribbean islands, and Australia. The parasite has additionally been reported from the Canary Islands and Balearic Islands of Spain, in addition to southeastern components of the United States, the place there have been a handful of circumstances of rat lungworm illness. Climate change might result in its additional unfold into at present extra temperate areas.

Hawai’i is a worldwide middle of the incidence of rat lungworm illness, and certainly it was in Hawai’i the place the connection between the parasite and the disease was first found, by University of Hawai’i and US authorities scientists within the early Sixties.

“Several species capable of acting as carriers (paratenic hosts) are present in Hawai’i, including flatworms, centipedes, coqui frogs, and cane toads,” mentioned Cowie. “While people in Hawai’i are unlikely to eat these animals, it is not unknown for people to do so on a dare, and become seriously ill. Elsewhere, certain paratenic hosts are eaten for supposed health reasons—frogs in Taiwan and Japan, or to enhance virility—lizards in Thailand.”

Domestic animals, particularly canine and horses, can even turn out to be contaminated by the rat lungworm parasite, together with in Hawai’i, most likely principally from unintentionally or intentionally consuming snails or slugs.

Preventing an infection

There are a number of issues individuals can do to forestall an infection by rat lungworm.

“Awareness of which species may harbor the parasite is critically important both in Hawai’i and more widely,” mentioned Cowie. “These animals should not be consumed raw. Additionally, wash all fruits and vegetables well under running water and inspect them for slugs, snails and possible other hosts such as flatworms so as to avoid inadvertently eating them or parts of them.”