Fatal zoonosis: this is why fox disease spreads

She has a nice name. However, she is deadly. The “fox disease” is spreading in our regions. At the end of the XX^e Century, between 10 and 30 new cases of alveolar echinococcosis – it was its small scientific name – per year. We are now around 70, according to a recent study published in the scientific journal “The Lancet Infectious Diseases”. Switzerland is even the second most affected country in Europe after Lithuania.

We can contract the disease by eating strawberries or garlic from bears contaminated by the droppings of a sick fox and picked up in the undergrowth. An activity to which always more Swiss indulge. Experts, however, call for not panicking. Alveolar echinococcosis remains rare. And even very rare. The estimated incidence is 0.06 cases per 100,000 inhabitants. Let us dissect this disease still little known to the general public in five questions.

Why are there many cases in Switzerland?

The Jura is the most affected area in Europe. The number of cases is therefore particularly high, as well as in the surrounding regions. “In France, for example, alveolar echinococcosis is mainly present in the northeast of the country,” says Émeline Gauthiez, a clinical head of the CHUV infectious diseases. In Germany, the prevalence is more important in the South and the East. Conversely, all of Switzerland is considered to be at risk zone. This may explain a greater proportion of cases. “

However, not all regions are also affected. On the set and in the Jura, 30% to 70% of the foxes are infected. And only 1% to 20% of alpine foxes. The figures we have for human contamination is also probably underestimated. “As it is not compulsory to report cases, statistics are based on hospitalizations,” explains the doctor. However, infected people may not have been to the hospital. ”

The increase in cases is multifactorial. “After the disappearance of rage in the 1990s, the foxes found their normal population on the one hand and extended their territory, including in the cities. On the other hand, the agricultural landscapes have changed deeply and the swarms of the Campagnols, the main food of the foxes, are now frequent, analyzes Michel Gauthier-Clerc, veterinarian and responsible for the Unige scienscope. Conversely, human beings go more and more in the wild where they consume contaminated plants. Climate change can also play a role. ”

Can vegetables in my garden also be contaminated?

Yes, especially if you live in rural or peri -urban areas. THE foxes,, whose natural habitat is always reduced more, explore more and more residential districts. They can then place their contaminated droppings in your vegetable garden.

Their faeces are not the only ones to fear. We must also pay attention to those of our faithful companions. Dogs, and cats to a lesser extent, can also be infected, if they have access to nature. The populations most at risk are however the game guards and hunters, because they handle potentially infected foxes or their excrement.

Human beings, however, remains an accidental host of echinococcus. The normal cycle involves Renards and Rodents. “The Campagnols-because they are the main rodents concerned-are the carriers of the parasite,” explains Michel Gauthier-Clerc. When the foxes eat them, they are infecting. Echinococcus releases its eggs in their intestines, and the foxes evacuate them naturally. Their infested droppings then defile plants that the Campagnols eat. ”

And history is repeated. Unless a human being enters the equation. If he takes the place of the rodent in the cycle and eats the soiled plant, he gets hell held. Human beings then develops cysts in their liver. In rare cases, the abdominal cavity, the lungs can also be reached. The brain too, but it is even rarer.

What are the symptoms?

They are often unimportant because the disease develops very slowly over years. “She is only painful if a cyst presses on a blood vessel,” says Émeline Gauthiez. Or that the bile hose is blocked, as it generates a jaundice. ”

The disease can be detected during an ultrasound or blood analysis, because the patient has abdominal pain, she continues. But it is also often in a fortuitous way, for example, during a routine check-up.

Do we necessarily die after being infected?

No. It is even more and more rare. “It only happens if echinococcosis is very advanced, reports Émeline Gauthiez. If the lesion is not too large, we can do an operation and remove the part of the infected liver. Patients must then take antiparasitic treatments for two years. And they are healed. “

For some patients, surgery is not possible. Either because they are too old, or because the disease invades the liver too much. They then receive an antiparasitic treatment for life which slows down or stabilizes the progression of the disease, but does not heal it. “Thanks to antiparasitic treatments, you can live for a very long time. They drastically elongated the life expectancy of people with alveolar echinococcosis. ”

What measures can we take to avoid catching the disease?

The first is to close your vegetable garden to prevent animals from coming to do their needs. We are talking about foxes here, but also of our pets. Dogs and cats must also be treated with deworming twice a year.

Fruits and vegetables, picked in the vegetable patch or in the forest on the ground, must be well washed and ideally cooked. “Washing limits the number of eggs, but it is not a 100%safe measure,” notes the CHUV clinic head. With cooking, they are definitely inactivated. However, freezing is used for no way. ”

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