Insects would be sensitive to an odor given off by sweat: that of lactic acid. But in some people, other elements can also attract them.
- Our sweat or the carbon dioxide released by our body can attract mosquitoes
- Certain blood groups have a higher risk of being bitten
- Mosquitoes cannot transmit the coronavirus
The arrival of summer coincides with the return of mosquitoes. These little insects can put us through hell. But we are not all equal in the face of their bites. Some people are much more prone to it. For many years, science has sought to elucidate this mystery and several hypotheses are emerging.
Insects attracted to sweat?
In 2019, a study published in the journal Cell recounts an experiment conducted by researchers at the University of Florida. They genetically modified female mosquitoes Aedes aegypti, known to transmit yellow fever, dengue and chikungunya. These insects have an olfactory receptor called IR8a: thanks to it, they can detect the smell of lactic acid in sweat. When researchers deactivated this receptor in genetically modified mosquitoes, they found that they were half as attracted to humans as compared to unmodified mosquitoes.
Carbon dioxide and the blood type in question
Mosquitoes are also attracted to CO2, but we emit it by breathing and sweating. Previous research indicates that they could detect it from 50 meters away. Pregnant women would be the preferred targets of insects because they release on average 20% more carbon dioxide than the average.
Blood type can also influence the risk of being bitten: people with groups A and O are generally more affected. Other research has been carried out on monozygotic twins, whose genetic heritage is identical, and dizygotic, who share only 50% of DNA in common. This allowed the researchers to see that mosquitoes favor carriers of certain genes. Indeed, twins attracted mosquitoes similarly while there were differences in fraternal twins.
Mosquitoes do not transmit Covid-19
Beyond the itching, mosquito bites can be serious: some of these insects carry diseases that they transmit to humans. Zika, dengue or yellow fever are among these pathologies. In this period of global pandemic, the mosquito worries: can it also transmit Covid-19? Researchers from the national institute of health in Italy are reassuring. According to them, the mosquito cannot transmit the virus. When the mosquito bites an infected person, SARS-COV-2 does not replicate in the insect’s body and cannot be subsequently inoculated during another bite.
.
