Raccoons may seem harmless roaming city streets or forests, but they carry a hidden threat: a parasitic worm that can infect humans and wildlife. Since animals first arrived in Europe from North America in the early 1900s, they have been brought with them Baylisascaris procyona parasite that is quietly spreading across the continent.
What is happening?
After escaping or being released from fur farms, raccoons have spread across much of Central Europe – and so have the parasites they carry. Germany is now the main distribution area for both.
A He studies Led by Professors Sven Klimpel and Anne Steinhoff from Goethe University Frankfurt, they looked to map the spread of roundworm in Europe and identify areas in need of further research, according to a new study. press release. To do this, Klimpel and Steinhoff examined 146 raccoons from Germany via necropsy, and combined their findings with a review of existing data from across Europe.
Infection rates were high: 77.4% of raccoons in Hesse carried the parasite, along with 52.9% in North Rhine-Westphalia and 51.1% in Thuringia, where such data were recorded for the first time.
“The results show an expansion of the roundworm distribution area and stabilization of infection incidence at high levels in German raccoon populations,” says Klimpel. He said.
Looking beyond Germany, the analysis found that wild raccoons in nine countries, mostly in Central Europe, are infected, and that infection rates are very high in some areas. In three additional countries, cases have been reported in captive raccoons or other animals.
TCD Picks » Upway Spotlight
💡Upway makes it easy to find discounts of up to 60% on premium e-bike brands
Why is this spread alarming?
Cases of human infection, known as bilisasicariasis, are rare but serious. “If the larvae enter the central nervous system, the disease can have serious consequences,” Steinhoff explained. “Due to frequent hand and mouth contact, young children are primarily affected.”
In North America, home to raccoons and roundworms, infection often results in permanent neurological damage or death. European cases, although rare, have led to permanent visual impairment.
The spread of the parasite is closely linked to the raccoon population, which is growing and growing in urban areas. As raccoons adapt to city life, the potential for human exposure increases. “The actual distribution of roundworm is likely to be significantly underestimated due to insufficient or absent data collection,” Klimpel added.
What is being done to limit the spread of the parasite?
Researchers stress that monitoring raccoon populations and studying Baylisascaris procyonis in Europe is urgent. Preventing human infection starts with awareness: Keeping children away from raccoon toilets, washing hands after outdoor activities, and limiting raccoon access to urban spaces can help limit exposure.
In the broadest sense, study Invasive raccoons Their parasites also support conservation efforts. Understanding how raccoons outcompete native species helps protect local ecosystems, maintain natural food chains, and reduce the chances of spreading disease.
Get free TCD newsletters for easy tips to save more, reduce waste, and make smarter choices — and earn up to $5,000 toward clean upgrades in TCD exclusives Rewards Club.