The Fox Tapeworm

by Anja Grabs and prof Dr. Peter Kern

Starting off with the worst fact: If humans are seized with the fox tapeworm (Echinococcus multilocularis), they usually die. In its life cycle the fox tapeworm infests rodents, in Germany these are most of the times voles. The infested rodent is an alternate host and is weak due to the infestation so that it will now easily be captured by final hosts such as foxes, dogs, or cats. If humans absorb fox tapeworms that are for example in the fur of a pet, they will become a paratenic host, as they are no prey animals such as mice. Then the fox tapeworm is most of the times unnoticeably spreading out inside the infected human until after ten to twenty years first symptoms (for example icteric) occur. Like metastases they can affect the liver, lung, and brain. However, a radical surgery is only possible during the early stage. Without a permanent, lifelong intaking of anti-worm-medication, which will lead to a stable situation, most patients die due to a progressed disease with many malignant signs.

The good news is, that even though the fox tapeworm seems to be spreading out in Germany, only few humans are infected by it. According to the Robert Koch Institute in the year 2012, there was only one patient reported in Berlin with the disease „alveolar echinococcosis“ and nobody reported in the state Brandenburg, whereat due to the long time of incubation the current place of residence may not be the place of infection. The transmittance to the human body is not yet clearly resolved.

The popular belief in contracting the disease by eating wild berries is wrong: „There is no connection between eating wild berries and getting infected by the fox tapeworm.“, says prof Dr. Peter Kern from the European Echinococcosis Register in Ulm, Germany. It is merely noticeable that over 70 % of the patients are owners of cats or dogs. It is assumed that the multiple intaking of fox tapeworm eggs, that can be found in the fur of dogs or cats, may lead to an infection in the human. Therefore people can protect themselves the best by deworming their dogs and cats on a regular basis (every six weeks in endemic areas).

Foxes have followed the humans into the settlement areas. Food wastage and numerous dens offer them a habitat. There are people who feed foxes in order to comfortably watch them in their own garden. This must be stopped urgently! Garbage cans and other places for food wastage must be made inaccessible for wild animals. Is a fox seen on a regular basis in the garden, one shall make sure that the compost is free of food wastage as well, so that the fox does not find a food source here either.

If there is a fox-hole in the garden scaring him off outside the breeding time (which is from April until July) shall be considered. Killing the fox is just as pointless as killing beavers or racoons, as the territory will be recolonized by new foxes within a short time. For scaring off foxes the office of hunting in the county Oder – Spree is suggesting to put a cloth soaked with diesel or a disinfectant containing formalin into the fox-hole. The infestation of examined foxes in the county Oder-Spree was only 1.5 % between the years 2008 and 2010 and can therefore be classified as low.

Foxes are interesting predators that can only be watched in nature with a lot of patience and a little bit of luck. Decoying them however by feeding them on purpose shall be desisted due to the danger for humans of receiving the infection of the fox tapeworm.