Dengue fever has come to Europe: should Russians be afraid?

Global warming has become one of the reasons for the spread of disease carriers, which previously survived only in warm regions. And if just a few years ago Dengue fever was considered a purely tropical disease, now it is increasingly taking on a European face.

The Asian tiger mosquito Aedes Albopictus began to spread in the south of Europe, and is now slowly conquering the north. Can a dangerous blood-sucking creature take root in Russia? MK learned about this from experts.

The tiger mosquito Aedes Albopictus is a mosquito that transmits tropical diseases such as Dengue fever, Zika virus, and chikungunya fever. Previously, it was found only in the countries of Southeast Asia (Indonesia, India, Sri Lanka, Maldives, Angola): the mosquito requires a warm and humid climate. But a few years ago everything changed: the bloodsucker began to settle in Europe.

Last week, Paris launched the city’s first mosquito control campaign to eradicate the Aedes albopictus mosquito that spreads dengue fever. Pest control contractors sprayed insecticide on trees, green spaces and other mosquito breeding areas.

The reason for the spraying was two cases of Dengue disease in Parisians. And although both cases are imported, authorities fear that if a tiger mosquito bites a person who brought the virus from abroad, he will become a carrier of the disease. Because the mosquito has long taken root in Paris and beyond. The European Center for Disease Prevention and Control reports that France has seen numerous cases of local infection – 65 in 2022 and 4 in 2023. Most of them occur in the southern part of the country, where the Mediterranean climate preferred by this mosquito species prevails. .

The Asian tiger mosquito A. albopictus was first discovered in France in 1999. Subsequently, it became extinct, but in 2004 it suddenly revived and became an endemic species. As a result, the south of France has been plagued by tiger mosquitoes for several years. Today, according to the Ministry of Health, Aedes albopictus is present in 71 of the 96 departments of the mainland, even in areas located near the northern coast of the English Channel. This is 4 departments more than a year earlier. French health authorities have placed these departments at a “red alert” level.

In neighboring Spain and Italy, cases of local infection have also been reported over the past 5 years. In addition, scientists report that this species of mosquito, by all indications, is rapidly moving towards the north of Europe. Aedes albopictus has already settled in such uncharacteristic latitudes as Germany and Switzerland. Health experts say the species’ prosperity on the continent is primarily due to climate change, with warmer weather shortening the incubation period for eggs and winters no longer being cold enough to kill off the pests.

Entomologists conducted experiments to track how climatic factors affected the species’ invasion and found that, unlike its cousin Aedes aegypti, which lives in tropical climates, Aedes albopictus is able to withstand lower temperatures for longer periods of time.

…Global warming has already led to the fact that infections that have never been seen here before have begun to occur in Russia. In Moscow alone, over the past 125 years, the average annual temperature has increased from 3 to 5.5 degrees, and the soil has practically stopped freezing in winter. For example, tropical infection specialists have in recent years increasingly encountered local cases of heartworm disease, a parasitic disease that affects both dogs and humans. It is also transmitted by mosquitoes through their bites. The disease is dangerous because there are no even ideas about the prospects for its diagnosis and treatment today. Several years ago, infectious disease specialists compiled a map of the Moscow region areas where these dangerous blood-sucking creatures live (which included the Naro-Fominsk, Shatura, Volokolamsk districts). There is a known case when, for example, heartworm was found in a 76-year-old Muscovite who had not left Moscow.

However, mosquitoes of the genus Aedes do not yet live in our climatic conditions. As the head of the Department of Infectious Diseases and Epidemiology told MK, RNRMU named after. N.I. Pirogova, Doctor of Medical Sciences, Professor Vladimir Nikiforov, for the development of the Dengue fever virus in mosquitoes of the genus Aedes, a high ambient temperature is needed: “Perhaps the explanation for the appearance of local cases of infection in the south of France is the abnormally high heat that was recorded there in the past and this year. The virus can survive in Egypt, Thailand, even Eilat, but not here. If our temperature rises, everything is possible: everything depends solely on the climate. We cannot influence this; we can only watch the development of events. We won’t be able to control mosquitoes. But we don’t have that temperature yet. As for the vaccine, its creation is hampered by a number of intractable problems.”

Well-known virologist and molecular biologist, Professor Konstantin Severinov told MK that the reason for the appearance of the tiger mosquito in Europe was climate warming and a shift in the ranges of biological species to the north: “It is difficult to say whether there is a chance that this mosquito will be able to spread in Russia. In most of our country the climate is not Mediterranean or even Parisian. Therefore, I assess the chances as low or very low.”

…We must remember that mosquitoes carry a lot of unpleasant and terrible infections. The only way to prevent infection is to avoid mosquito attacks. Therefore, you need to take care of preventive measures, especially in exotic countries – use repellents and nets on windows. In hotels, do not open windows unless they are equipped with mosquito nets, use air conditioning. And, of course, if you feel unwell, consult a doctor immediately.