Peter Gillespie ’25
Mosquitos continue to become a burden on global health as rampant vectors for disease, embedding threatening viruses beneath itchy welts that are a nuisance in themselves. However, while one person might return from a mosquito-laden environment riddled with these welts, another might escape unscathed. New research from De Olbadia et al. reveals that this phenomenon is not mere unlucky coincidence, but rather stems from the quantities of certain chemicals produced on our skin that attract mosquitos.
Mosquitos have two types of receptors, odorant and ionotropic receptors, which are activated in response to certain chemical groups on our skin. However, combinations of chemical groups that most entice mosquitos had previously been unknown. To uncover the determinants of mosquito attraction, researchers exposed mosquitos with mutated receptors to skin odor samples from 64 different participants. The mosquitos could attempt to infiltrate either of the two samples, and the researchers deemed the samples as highly attractive or slightly attractive based on the frequency of mosquito visits. Based on the chemical groups present in the samples and which mutated mosquitoes were attracted to them, the researchers were able to determine the chemical groups and the receptors that play important roles in mosquito attraction.
Analysis of the highly attractive samples shared an important commonality: an abundance of carboxylic acids. As the three most significant carboxylic acids– pentadecanoic, heptadecanoic, and nonadecanoic acid– were present in different quantities within the most attractive samples, researchers suggest that varying formulations of these chemical groups can result in a mosquito’s attraction to a person. Additionally, there were no shared characteristics among the poorly attractive samples, suggesting that lack of attractants rather than the presence of common repellents keeps a person bite-free.
Specific mutations to mosquito receptors did not impact preference for any of the samples. This suggests that the mechanisms mosquitos use to detect attractants is redundant among the various receptors. This further places a mosquito-attractive person at risk, as the generalizability of the attractants present on their skin is not protected by any mutation that may be present within mosquito populations. While the study cannot produce an exhaustive list of all possible attractants, it provides strong support for differences in individual skin composition that attract mosquitos, which in turn can be used to help identify pathways to reduce the burden of mosquito-driven illnesses.
 M. De Obaldia, et al., Differential mosquito attraction to humans is associated with skin-derived carboxylic acid levels. Cell 185, 1-18 (2022). doi: 10.1016/j.cell.2022.09.034.
 Image retrieved from: https://pubmed.ncbi.nlm.nih.gov/36261039/