Scientists recently shed light on the age-old question of why mosquitoes prefer to bite certain people over others. Through extensive research, they discovered that the chemicals secreted from people's bodies, including body scent and the unique "skin climate" that certain individuals exude, play a role in making some individuals more attractive to these biting insects.
In a study, researchers found that individuals with higher levels of certain acids on their skin are 100 times more attractive to female Aedes aegypti mosquitoes, which are responsible for spreading diseases such as dengue fever, chikungunya virus, yellow fever, and Zika virus. One particular participant in the study, known only as Subject 33, attracted mosquitoes four times more than the second most attractive participant and 100 times more than the least attractive.
"Subject 33 won a hundred games. They were completely undefeated. No one beat them," said Leslie Vosshall, head of the Neurogenetics and Behavior Laboratory at Rockefeller University and chief scientific consultant at the Howard Hughes Medical Institute. The secret of Subject 33's attraction was an unusually high presence of carboxylic acids on their skin. Carboxylic acids are a component of natural body odor, and everyone produces them through sebum, the waxy coating on the skin.
In the experiment, eight participants wore nylon socks on their arms for six hours daily over multiple repetitions to collect their body scent. The nylon stockings were cut into small pieces and placed in chambers with mosquitoes. The mosquitoes consistently flocked to certain scent samples while completely ignoring others, showing clear preferences. "You could tell within the first few seconds that the sample belonged to Subject 33, because the insects were heading in swarms toward it," said Maria Elena De Obaldia.
The study found that these scent-based preferences remained stable over time. The research team repeated the process with an additional 56 participants, showing that Subject 33 remained extremely attractive even years later. Vosshall stated, "Only when you understand what makes people mosquito magnets can you start thinking of ways to stop that." She added that the composition of the skin microbiome is unique to each individual. "Everyone has a completely unique village of bacteria living on their skin," she said.
Scientists are hopeful that understanding why some people are more prone to mosquito bites could change mosquito control and repellent design. Future repellents might target the specific chemical signatures that mosquitoes crave, potentially leading to new products that could cover or modify certain human odors, making it harder for mosquitoes to find human blood.
Mosquitoes are not merely buzzing pests; they are deadly vectors that contribute to over 700 million infections globally each year, including serious diseases such as malaria, dengue fever, filariasis, and tularemia. Dr. Alexandra Filieva recommends not to underestimate mosquitoes, because they carry serious diseases, contributing to over 700,000 deaths annually from mosquito-borne diseases.
Scientific research has revealed that mosquitoes show more interest in a certain blood group. According to research conducted by the Japan Institute of Pest Control, individuals with blood group O are the number one target of mosquitoes and are bitten approximately twice as much as those with blood type A. Dr. Filieva added that individuals with blood group B have a medium level of risk of being bitten by mosquitoes.
People often blame their blood type or bad luck for being targeted by mosquitoes. However, science suggests a more substantial reason for mosquito attraction: the chemical signature of a person's skin. The study focused exclusively on compounds with carboxylic acid groups, providing a promising lead in understanding mosquito preferences. Vosshall noted that "the mosquito olfactory system is extremely complex and has multiple detection mechanisms." She described the result as "disappointing," explaining that even when one type of receptor was disabled, mosquitoes remained capable of detecting and preferring "magnets" like Subject 33.
LJ Zwiebel, a professor of biological sciences at Vanderbilt University, stated that while carboxylic acids are clearly involved in the study, there is not "one single compound" that attracts mosquitoes. "It is likely a 'cocktail' of different ingredients that signals the mosquito to focus and bite," he said.
Research findings indicated that certain soaps, perfumes, and lotions increased mosquito attraction, particularly those with fruity or floral scents. Additionally, factors like lactic acid that accumulates in the body during exercise, increased body temperature, and veins close to the skin surface make it easier for mosquitoes to find you. For individuals who do not want to be bitten by mosquitoes, Zwiebel advised, "Shower to reduce all those juicy compounds on your skin, especially around your feet, with their unique odors."
Scientists have found that women seem to become more attractive to mosquitoes when they are pregnant. People, regardless of gender, seem to attract more mosquitoes after consuming beer. Experts expect the number of cases of mosquito-borne diseases to increase as global temperatures rise.
Until science finds a way to mask or neutralize those signals, the best defense against mosquitoes might still be repellents, covered clothing, and clever timing. Scientists may be able to develop a probiotic skin cream that interferes with or reduces the levels of certain byproducts, which could make a person less attractive to mosquitoes. Vosshall concluded that understanding what makes people mosquito magnets is essential for developing ways to stop that.
Produced with the assistance of a news-analysis system.