BPCA news archive

09 October 2019

Rat lungworm’s sluggish journey to Europe

Scientists are looking into the spread of rat lungworm to several popular European holiday destinations.

First noted in China in the 1930s, rat lungworm is widespread in Southeast Asia and the Pacific islands.

However, in the last decade, the parasite has been found in the Balearic islands, and it is believed that climate change and globalisation are to blame for its spread to Europe.

 287 rat lungworm snails hosts

What is rat lungworm?

Rat lungworm or Angiostrongylus cantonensis, is a parasite that multiplies in the lungs of rats, its preferred host, but can be spread by snails or slugs.

Rodents harbour the adult worm in their lungs, and as the life cycle continues the larvae of the parasite pass into the throat of the rat, are swallowed and excreted in the rat droppings.

Snails or slugs then pick up the larvae in the droppings, at which point they become something called an “intermediate host” as the larvae continue to evolve.

People then become infected by eating raw or undercooked snails. Children have even been known to become infected after swallowing slugs “on a dare”.

Crucially, it cannot be spread from person to person and it is very unusual for someone to become ill as a result of this parasite.

Although some people show no symptoms when infected, sometimes it causes a rare type of meningitis (eosinophilic meningitis). However, in most cases, the parasite will die over time - humans are not its preferred host.

Other animals, such as dogs and horses, are at risk of infection, leading to breathing problems, weight loss and excessive bleeding.

Spread to Europe

Rat lungworm is what’s known as an “emerging disease”, which means it is spreading to countries it has not previously been linked to.

First recorded in the EU on Tenerife in 2010, the parasite was then found in two hedgehogs on the island of Mallorca in 2018.

Scientists from the University of the Balearic Islands wrote a journal about the case and concluded that it is likely that the parasite will be actively transmitted on the island and spread further over time.

Advice to prevent infection is to thoroughly wash raw fruits and vegetables, and cook any molluscs or similar food thoroughly before eating.

With a view to Mallorca, scientists say that more data still needs to be gathered, specifically how common the larvae are in snails.

Source: Online