Holiday warning as deadly ‘raccoon worms’ that trigger brain swelling and blindness in humans are found across Europe

A RACCOON parasite which attacks the human nervous system is spreading in popular tourist spots across Europe.

Six raccoons found in Wallonia, southern Belgium, tested positive for Baylisascaris procyonis - a roundworm that lives in the animal.

It has also been found in France, Germany, the Netherlands, Luxembourg, Denmark, and the US, among other places.

It's the first time the worm, which is relatively harmless to raccoons but can be fatal in humans, has been spotted in Belgium, according to The Wallonia Public Service ().

"The risk of being contaminated is low, but the seriousness of contamination should not be overlooked," stated Annick Linden of the Wildlife Health and Pathology Service, whose department is credited with identifying the parasite.

A rare parasitic infection can occur if humans accidentally ingest the eggs, which live on the animal's fur, in their poo and in their environment.

After the eggs have been eaten, they hatch into larvae that travel through blood vessels and invade organs, including the eyes and brain.

Once they reach the organs, they can cause serious inflammation, leading to irreversible damage.

While some people make a full recovery, the infection can leave others blind, in a coma, with deadly encephalitis (brain swelling) or with permanent brain damage.

Those visiting the area, famous for its medieval towns and beer, must stay away from raccoons and not feed them, the WPS said.

Parents should keep an eye on children, who are at high risk of infection, to ensure they do not put anything strange in their mouths.

Hikers have been warned to only pick wild berries that hang too high for raccoons to reach, which they say is at least 50cm above the ground.