Europe, June 24. 2025
A systematic review published in the renowned journal The Lancet Infectious Diseases (June 2025) reveals that alveolar echinococcosis – a life-threatening zoonotic disease caused by the fox tapeworm Echinococcus multilocularis – is on the rise across Europe. Between 1997 and 2023, over 4,200 human cases were documented, with steadily increasing numbers in nearly all affected countries. From 2021 to 2023 alone, 828 new cases were reported – nearly three times as many per year as in previous years. Countries in the Alpine and Baltic regions, including Switzerland and Germany, account for around 90% of all cases. Case numbers are expected to continue rising, as symptoms in humans may not appear until 10 years or more after infection.
What explains the recent increase?
Since the successful control of rabies in Europe, fox populations have rebounded significantly and are now frequently found not only in forests but also in urban and suburban areas. Foxes are the main definitive host of Echinococcus multilocularis and can excrete large quantities of infectious eggs into the environment via their feces – contaminating meadows, gardens, playgrounds, and agricultural land.
Dogs, too, can become infected by hunting rodents, the parasite’s main intermediate hosts. Once infected, dogs can shed eggs into households via their fur or feces and infect humans – often without showing any clinical signs themselves. Because the disease in humans typically has an incubation period of 5 to 15 years, today’s rise in cases likely reflects ecological and behavioral changes that began a decade ago – a trend that is expected to continue. The increase in dog ownership in recent years may further contribute to transmission risk.
Berries are not the main problem
For a long time, the consumption of wild berries was considered the most important risk factor. However, the new study confirms a more nuanced view that has already been suggested by previous research: While contaminated food can contribute to transmission, infected pets – especially dogs – appear to pose a significantly higher risk to humans.
Why untreated dogs are a real risk
Many dogs – particularly in rural areas – hunt rodents and can become infected. They remain symptom-free but may continuously shed eggs that are invisible to the naked eye. Close contact with infected dogs creates a direct transmission risk for humans, especially in households with children or immunocompromised individuals.
Takeaway: regular deworming is essential!
Deworming dogs regularly is not only a matter of animal health – it is also crucial for protecting humans from infection. In endemic areas, quarterly treatment with appropriate anthelmintics is strongly recommended. This applies especially to hunting dogs, farm dogs, or pets that roam freely outdoors.
Source: Unveiling the incidences and trends of alveolar echinococcosis in Europe: a systematic review from the KNOW-PATH project. Casulli, Adriano et al., 2025. The Lancet Infectious Diseases. https://doi.org/10.1016/S1473-3099(25)00283-X
