The researchers who have just identified this phenomenon around the dengue and Zika viruses conducted their experiments on mice. But everything suggests that the phenomenon applies to humans. And while the discovery is worrisome from a public health standpoint—no one likes the idea of more disease-carrying mosquitoes—it opens the door to techniques to reduce the risk: reduce the odor or even block it.
It has long been known that certain diseases change the smell of their host, to the advantage of micro-organisms. Plants infected with cucumber mosaic virus, emit a molecule that attracts aphids, or aphids, from which the virus will infect other plants. Malaria is also known for the change in odor it causes, detectable by mosquitoes which then transmit the disease. However, we did not know what happened with Zika and dengue, two similar viruses transmitted by mosquitoes Aedes that breed in stagnant water.
The authors of the research, published on June 30 in the review Cellevaluated that mice infected with either of these viruses emitted 10 times more acetophenone. They also found that coating uninfected mice with acetophenone attracted mosquitoes there too — and they repeated the experiment with a few humans protected from the bites.
In normal times, bacteria present on the surface of our skin naturally produce this substance, but in return, an antimicrobial protein, produced by skin cells, limits their number. The gene responsible for this protein would be less active in mice infected with dengue fever or Zika.