The tiger mosquito invades Switzerland: diseases

The tiger mosquito can transmit several pathogens.Keystone

Particularly harmful, the Asian insect multiplies in our country and can be a vector of different diseases. Here is the list.

The Asian tiger mosquito is spreading more and more in Switzerland. With him, the risk of diseases that we knew so far especially in the tropics settles in the country. Because this striped little mosquito can transmit these pathogens. An overview:

Le chkwunka

The tiger mosquito can spread the chikungunya virus. According to the Federal Office for Public Health (OFSP), the virus is generally not dangerous. Fever and strong joint pain may however persist for weeks or even months, in many affected people.

The serious developments are rare, but they occur in particular in the elderly or the seriously sick people beforehand. According to the World Health Organization (WHO), the mortality rate is lower than one percent.

So far, no one has been contaminated by the chikungunya virus in Switzerland. All cases of chikungunya recorded in Switzerland were due to contaminations during trips to other countries.

In July, the World Health Organization, however, warned of a global epidemic of this viral disease transmitted by mosquitoes. The disease has already been detected in 119 countries, including in Europe.

A few days earlier, a person had been infected for the first time by the chikungunya virus in Lipsheim (F), just a hundred kilometers from Basel. Despite this, the Federal Office for Public Health believes that the probability of local transmission in Switzerland remains very low. To date, there is an authorized vaccine against chikungunya in Switzerland.

Dengue

Tigers mosquitoes can also transmit dengue. Not all people infected with dengue are ill. According to the OFSP, the infection is asymptomatic in 40 to 80% of cases. Those who feel symptoms have classically a high fever, headache, joint pain and rashes.

But dengue is particularly dangerous during a second infection, as the risk of developing a serious illness is then higher. In recent years, the number of dengue cases has greatly increased worldwide. In Europe too, isolated transmissions have taken place.

In Switzerland, no transmission has been held so far, but more and more travel return travelers are infected. In Switzerland, a dengue vaccine has been authorized since the end of July 2024. It is only recommended to people who have already undergone a first infection and who travel to regions at risk.

And Virus Zika

The Zika virus is another virus transmitted by the tiger mosquito. In adults, it generally does not cause symptoms or light symptoms. In 60 to 80% of cases, the infection is asymptomatic. In other cases, multiple symptoms may appear and, in rare cases, serious neurological complications are possible.

In children to be born, an infection of the mother by the Zika virus can also lead to serious malformations. Pregnant women also have an increased risk of complications.

In Europe, the first cases of Zika transmitted locally were observed in France in 2019. In Switzerland, there has not yet been local transmission. There is currently no vaccine against Zika, but according to the Travel Medicine Center at the University of Zurich, several zika vaccines are being developed.

The Virus of Western Nile

The tiger mosquito can also transmit the Western Nile virus. However, other native mosquitoes can also spread this disease. In Europe, according to the OFSP, it is above all the two species of Culex Pipiens mosquitoes – the European domestic mosquito mosquito – and Culex Modestus that seem to play an important role in the propagation of the virus.

The Western Nile Virus is mainly present in wild birds, but mosquitoes can also transmit it to horses and humans. According to the OFSP, around 80 percent of people infected with the Western Nile virus have no symptoms.

After an incubation period of 2 to 14 days, 20 percent of infected people develop symptoms similar to those of the flu, with a high fever, sometimes accompanied by redness on the trunk. Complications such as encephalitis and meningitis are rare, in less than one percent of infected people, especially in the elderly. In very rare cases, these complications can lead to death.

The Western Nile Virus is present on all continents, cases have recently been reported in Europe. In Switzerland, it was detected for the first time in native mosquitoes in August 2022. (JZS/ATS)

A wolf having killed seven pension animals in a protected situation in the space of a month was killed this Monday morning in the Conches region.

A wolf was shot in the Conches region on Monday morning. The head of the Valais department of economics and training (DEF), Christophe Darbellay, had ordered one of these animals installed in the region last Thursday. The large predator had killed seven pension animals in a protected situation in the space of a month.