The age-old question of why some people seem to attract more mosquitoes than others has finally been given a scientific answer. A study from Florida International University (FIU) has revealed that no single person is a "mosquito magnet" for all species, but rather, different mosquitoes are drawn to distinct body odors and skin microbiomes.
The experiment, published in the journal iScience, involved 119 adults and three major disease-carrying mosquito species: Aedes aegypti, Aedes albopictus, and Culex quinquefasciatus. The results showed that certain individuals are indeed more prone to bites from specific mosquito species, but not universally.
One of the most intriguing findings was the lack of correlation between individual attractiveness to different mosquito species. Aedes aegypti and Aedes albopictus showed a weak tendency to be attracted to the same individuals, but almost no correlation was found between Aedes aegypti and Culex quinquefasciatus, or between Aedes albopictus and Culex quinquefasciatus. This suggests that mosquitoes use different chemical cues when locating hosts.
The key variables identified were human body odor and skin microbiota. Mosquitoes use a combination of sensory inputs, including carbon dioxide, body odor, visual cues, humidity, and heat, to locate their blood-meal targets. Human body odor, in particular, is a complex blend of over 1,000 volatile organic compounds (VOCs), many of which remain uncharacterized.
The microbial communities living on human skin break down sweat and sebum components to produce unique volatile compounds, which is why each person has a distinct body odor. The study identified 246 bacterial taxa, yet only one bacterial species was common to all participants. The composition of bacterial taxa also differed between individuals with high and low attractiveness to each mosquito species.
Specific links to body odor components were also revealed. Attractiveness to Aedes aegypti and Culex quinquefasciatus was associated with lower levels of certain odor compounds, such as cyclic alcohols and monoterpenes. Conversely, Aedes albopictus tended to be more attracted to people with abundant ketone-based odor compounds. This indicates that the sensitivity of chemical receptors varies across mosquito species.
Gender-based differences were only significantly observed in Aedes aegypti. The average attraction rate for this species was 91.5% for males and 87.4% for females, a 4.1 percentage point difference in favor of males. No statistically significant gender differences were found for Aedes albopictus or Culex quinquefasciatus.
The mosquito species used in the experiment are of significant public health importance, as they are capable of transmitting deadly infectious diseases. Aedes aegypti and Aedes albopictus spread flaviviruses that cause dengue fever, Zika virus, and yellow fever. Culex quinquefasciatus is known as the primary vector for West Nile virus.
The research team believes these findings will serve as crucial foundational data for formulating infectious disease prevention strategies, extending beyond the simple question of "who gets bitten more." If future research can more precisely identify which specific odor compounds attract or repel particular mosquito species, it could lead to groundbreaking advances in developing species-specific repellents and strategies to combat mosquito-borne diseases.
This study has been praised for moving beyond conventional wisdom that attempts to explain mosquito bites through single factors like blood type or body temperature, instead providing scientific evidence that body odor, skin microbiota, and the sensory characteristics of mosquito species interact in a complex manner.
