Mosquito: Dengue and Zika viruses alter your smell to attract them

All sorts of factors attract mosquitoes to us, but people infected with Dengue and Zika virus are even more attractive to mosquitoes than healthy people. What is behind this observation?

The tiger mosquitoes (Aedes albopictus) have been present in France since the arrival of fine weather. In tropical regions, they bite throughout the year and are responsible for the transmission of many viruses, the main ones being Zika, chikungunya and the dengue virus. Scientists are particularly interested in the factors that attract mosquitoes the diseases they transmit are a real public health issue.

The colourCO₂ expired, sweat or blood type are factors that can attract mosquitoes. But recent research, conducted at the University of Connecticut, shows that smell also has a role to play, especially in people infected with the dengue virus and Zika. Indeed, if it has the choice between a person carrying dengue fever or Zika and a healthy person, the mosquito will prefer to bite and drink the blood of the first.

Acetiphenone, a perfume for mosquitoes

The results were obtained on laboratory mouse and volunteers. Scientists have analyzed the molecules fragrant substances present on the surface of the skin of rodents infected to understand which was the most attractive for insects. Each molecule was applied individually to the skin of the volunteers’ hands and it appears that acetophenone attracts mosquitoes the most. This compound aromatic is present in many foods and is used in the formula of perfumes with notes ofalmondof cherry or of honeysuckle.

Acetophenone is naturally secreted by certain bacteria in the microbiota of the skin, Bacillus. In healthy patients, the population of Bacillus is controlled by a peptide antimicrobial, but in people infected with dengue virus and Zika, this antimicrobial peptide is produced in lower amounts. As a result, the bacterium proliferates and “perfumes” infected people with an odor appreciated by mosquitoes. ” Virus can manipulate hosts’ skin microbiota to attract more mosquitoes and transmit faster “, explains Penghua Wang, immunologist at the University of Connecticut.

The scientists also observed that a molecule derived from vitamin Awhich intervenes in the biosynthesis of the anti-microbial peptide, makes it possible to reduce the attraction mosquitoes for patients infected with dengue virus and Zika.