“Two to three dengue patients” per week at the University Hospital of Bordeaux. Tiger mosquito control operations intensify

Professor Malvi, an infectious disease specialist at the University Hospital of Bordeaux, warns. In May, the tiger mosquito is able to transmit it to another person by biting a person infected with dengue fever. “Hence the fact that we have to anticipate this with very simple civic gestures,” he says. We followed the preventive operation in Talence, Gironde.

In recent years, the number of preventive surgeries has increased throughout almost all of France, including in urban areas. Agents from the city of Talence and the Bordeaux Metropole mosquito control center are visiting people’s homes to intervene and warn. Operation Zero Mosquitoes was launched in 2023. It consists of giving residents some tips on how to avoid the spread of the tiger mosquito and prevent it from laying eggs. In fact, more than 80% of these apartments are located in private areas.

To do this, it is necessary to eliminate any water retention that may harbor larvae. That day, agents placed a bacillus in bodies of water that biologically attacks them. “These bacteria release toxins that attach to the cells in the intestinal wall and cause it to rupture.” explains Christophe Courtin from the Mosquito Control Centre. To avoid ruining your summer evenings, you just need a few simple steps. “We empty the plates, look into the gutters and wash them well.”“says Hélène Moreau, a resident of Talence. “A man from the city told us that some might be under the terraces, so that’s another problem, I mean.”

In Talence, agents gave residents a questionnaire to gauge their current opinions about mosquito numbers. “The results will be compared with those obtained during their subsequent visits, which will take place every month.”– explains the City of Talent.

That way, agents will know within months whether the spread has been contained.

The tiger mosquito was first spotted in New Aquitaine in 2012. It was in Lot et Garonne. It then spread towards the Atlantic coast and major urban centers. As a result, today it is present everywhere in our region except Croesus. Sometimes he carries the dengue virus.

According to Professor Malvi, an infectious disease specialist at the University Hospital of Bordeaux, there is no doubt that climate change is having an impact on the spread of certain viruses through tiger mosquitoes. “Climate change influences dengue disease through virus and mosquitoes”he analyzes. “Because mosquitoes need water and warmth. And the more unexpected environmental events occur or with distortions like those that we are targeting, then with strong alternations, drought, then intense precipitation… All this makes life easier for mosquitoes.

However, the professor refuses to talk about mosquito control and prefers to talk about “risk vector prevention.” “Dengue fever, which is of particular concern to us, is a virus that is practically transmitted from person to person by the tiger mosquito. he explains.

This is a risk that must be taken into account in mainland France.

Professor Denis Malvi,

Infectious Disease Specialist at the University Hospital of Bordeaux

For what ? “Because we have an extremely significant increase in intercontinental travel in a globalized world of people who come from endemic or epidemic areas, such as, for example, the Lesser Antilles, the Caribbean or Guyana, and who arrive in France, where there are mosquitoes. capable of transmitting this virus.

To support his comments, Professor Denis Malvi relies on reality. “At the University Hospital of Bordeaux, for example, we have two or three patients a week suffering from viraemic dengue fever, that is, with symptoms. he announces. “And this has been going on for months now.”

From the month of May we enter a period when the tiger mosquito, present in Aquitaine, becomes active.

Professor Denis Malvi,

Infectious disease doctor at the University Hospital of Bordeaux

“That is, when it bites a viremic person, it becomes capable of transmitting it to another person. Therefore, in chronological order, we face the risk of transmission.

“And this year, given the large number of travelers returning with viremia, nothing will stop us, the risk is inevitable due to local cases in France and Aquitaine. But we expect it.”

In 2023, the tiger mosquito was present in 71 departments of France. It can also be transmitted to humans viruses such as chikungunya or Zika.