Everyone gets bitten by mosquitoes, but some more than others. And this, according to researchers from Rockefeller University in the United States, is due to the way bacteria break down the sweat that comes out of the pores.
This fact is not new, the attraction of mosquitoes to humans has been studied since 1968, but with this study, researchers have used genetically modified mosquitoes and tested whether they react to a greater or lesser extent to fragrances on our skin.
Everyone has a different olfactory profile
“The liquid that comes out of our skin, sweat, is sterile and is broken down on the skin by bacteria. During degradation, fatty acids are released to which mosquitoes react,” says mosquito expert Bart Knols.
American research shows that people who produce more carboxylic acids, which are in the sebum, are more attractive to mosquitoes. “Everyone has attractive, repulsive fatty acids on their skin. It all depends on the ratio you have them in.”
Everyone has a different olfactory profile, for example a sniffer dog in a worn shirt can find someone in a group and this is how mosquitoes distinguish between two people lying next to each other in bed; one has more attractive fatty acids and fewer repulsive fatty acids than the other.
Better immune systems
“The composition of the fatty acids you have depends on various factors such as the acidity of your skin, your genetic background and your diet. Combined, these factors determine what your bacteria decompose on the skin and which acids are released.”
But what can you do with this information? Knols: “Once you know the composition that attracts mosquitoes, you could create better defense systems. This can be done by omitting the repellent odor and using only the attractive scents.”
Better electoral systems
“Looking further into the future, you could then create substances to be applied to the skin that can reduce the attractive odor that bacteria emit so that there are fewer spots,” says Knols. To continue immediately: ‘This is very difficult to achieve. It is a long, medical and ethical process “.
Knols is currently working in the Maldives and researching better mosquito trap systems. On ten islands he has over a thousand traps with human smells such as lactic acid, which resembles fatty acid. Together with other researchers, he is examining which combinations are used to catch the most mosquitoes.
That research, combined with mosquito larvae control at breeding sites, ensured that nearly all mosquito populations on ten islands were under control for more than six months. And this offers hope for the future. “It is an economical and ecological way to control mosquitoes and thus prevent the spread of the disease.”
Each mosquito is different
Not all mosquitoes react equally to fatty acids or lactic acid on the skin. American researchers tested with the yellow fever mosquito. Bart Knols works with the Asian tiger mosquito.
“They are sisters, so to speak, but they are quite different from each other. The tiger mosquito takes blood from people, birds, rats, mice, practically anything that can be found in nature. The yellow fever mosquito wants only blood from people and therefore reacts more strongly to the specific odors that people emit, which can fly in the wind in search of the source of the smell and end up with the one that has the most attractive fatty acids on the skin for the mosquito. “
Mosquitoes fight mosquitoes
The US state of Florida released 750 million genetically engineered mosquitoes into the wild two years ago. Mosquitoes can transmit dangerous diseases such as yellow fever, dengue fever and the Zika virus. They hoped to counteract it by intervening in the genes of the mosquito. Find out how they tried to fight mosquitoes below:
