Ziekteverwekker
Alveolar echinococcosis is a parasitic disease that affects certain mammalian species, including rodents, humans, and canids. The disease is caused by infection with the larval stage of a tapeworm species of the genus Echinococcus. In Europe, various species of Echinococcus tapeworms occur, which are responsible for different forms of echinococcosis. The alveolar form of this disease is caused by Echinococcus multilocularis, which is endemic in many parts of Europe.
Gevoelige diersoorten
Dogs and wild canids such as foxes and raccoons, and to a lesser extent cats, are the definitive hosts of these worms, but can sometimes also develop the cystic form of the disease (and thus function as intermediate hosts). In the normal life cycle, rodents are the intermediate hosts for the larvae of this parasite.
Symptomen dieren
Infection in the definitive host can be asymptomatic, meaning there are no visible symptoms. In rare cases, when very large numbers of worms are present, an intestinal obstruction may occur and signs of anal irritation may develop.
Besmetting dieren
Infectious eggs can be present in the feces of infected animals. These eggs end up in the environment and can land on vegetation (such as vegetables and fruit). Small rodents subsequently eat this and can become infected, acting as intermediate hosts. Foxes, raccoons, dogs, wolves, and cats can become infected by eating these infected rodents and are the definitive hosts of this parasite. In their intestines, the eggs develop into adult tapeworms.
Definitive hosts (i.e., dogs and other canids) become infected by eating raw or undercooked meat containing Echinococcus cysts. Farm or hunting dogs that have access to slaughtered carcasses or their offal are at the highest risk.
Intermediate hosts become infected through the ingestion of food contaminated with the feces of infected definitive hosts.
Symptomen mens
In people infected with E. multilocularis, clinical signs may not become visible until years later. This often reflects impaired function of the organ (or organs) in which the larval cysts formed; usually the liver and lungs.
Besmetting mensen
Humans can become infected by ingesting tapeworm eggs found in the feces of infected dogs. The main routes of infection are direct contact with infected dogs or the consumption of water or fruits and vegetables contaminated with dog feces.
Geografische verspreiding
Due to changing environmental and socioeconomic factors, the spread of E. multilocularis continues to increase. To date, the parasite has been reported in most countries of Northern Europe (with the exception of Norway and Finland) and Western Europe (with the exception of Spain and Portugal), while remarkably few regions in Southern Europe report cases.
Outside Europe, E. multilocularis is endemic in many countries in the Northern Hemisphere, including parts of the US, Canada, China, and Russia.
Voorzorgsmaatregelen
Pet owners are advised to regularly deworm their dogs and cats (particularly animals that hunt rodents) to minimize the risk of transmission from pets to humans. In some areas where the disease is endemic, local authorities use deworming baits to reduce infection levels in wild animals and stray dogs.
When collecting wild fruits and nuts, be aware of the possibility that they may be contaminated with the feces of infected carnivores.
Other control strategies include raising awareness among farmers, hunters, and the general public, and continuing surveillance of wildlife populations.
Sources
Enemark, H. L., Al-Sabi, M. N., Knapp, J., Staahl, M., & Chríel, M. (2013). Detection of a high-endemic focus of Echinococcus multilocularis in red foxes in southern Denmark, January 2013. Euro surveillance : bulletin Europeen sur les maladies transmissibles = European communicable disease bulletin, 18(10), 20420. https://doi.org/10.2807/ese.18.10.20420-en
Gemmell, M. A., Meslin, F. X., & Pawlowski, Z. S. (2001, December). WHO/OIE manual on echinococcosis in humans and animals: a public health problem of global concern.
Janovsky, M., Bacciarini, L., Sager, H., Gröne, A., & Gottstein, B. (2002). Echinococcus multilocularis in a European beaver from Switzerland. Journal of wildlife diseases, 38(3), 618–620. https://doi.org/10.7589/0090-3558-38.3.618
Rostami, A., Lundström-Stadelmann, B., Frey, C. F., Beldi, G., Lachenmayer, A., Chang, B. C. H., Norouzian, M. M., Hemphill, A., & Gasser, R. B. (2025). Human Alveolar Echinococcosis-A Neglected Zoonotic Disease Requiring Urgent Attention. International journal of molecular sciences, 26(6), 2784. https://doi.org/10.3390/ijms26062784