Scientists Discover Why Some People Are Mosquito Magnets

Mosquito (Aedes aegypti) Sucking Blood

A scientific study recently demonstrated that fatty acids emanating from the skin may create a heady perfume that mosquitoes can’t resist.

It can be impossible to hide from a female mosquito—she will hunt down any member of the human species by tracking our CO2 exhalations, body heat, and body odor. However, some of us are distinct “mosquito magnets” who get more than our fair share of bites. There are many popular theories for why someone might be a preferred snack, including blood type, blood sugar level, consuming garlic or bananas, being a woman, and being a child. Yet there is little credible data to support most of these theories, says Leslie Vosshall, head of Rockefeller University’s Laboratory of Neurogenetics and Behavior.

This is the reason why Vosshall and Maria Elena De Obaldia, a former postdoc in her lab, set out to investigate the leading theory to explain varying mosquito appeal: individual odor variations connected to skin microbiota. Through a study, they recently demonstrated that fatty acids emanating from the skin may create a potent perfume that mosquitoes can’t resist. They published their results in the journal Cell on October 18.

“There’s a very, very strong association between having large quantities of these fatty acids on your skin and being a mosquito magnet,” says Vosshall, the Robin Chemers Neustein Professor at The Rockefeller University and Chief Scientific Officer of the Howard Hughes Medical Institute.

Female Aedes aegypti Mosquito Bites Researcher

A female Aedes aegypti mosquito bites a researcher at The Rockefeller University. Credit: Alex Wild

A tournament no one wants to win

In the three-year study, eight participants were asked to wear nylon stockings over their forearms for six hours a day. This process was repeated on multiple days. Over the next few years, the investigators tested the nylons against each other in all possible pairings through a round-robin style “tournament.” They used a two-choice olfactometer assay that De Obaldia built, consisting of a plexiglass chamber divided into two tubes, each ending in a box that held a stocking. They placed Aedes Aegypti mosquitoes—the primary vector species for Zika, dengue, yellow fever, and chikungunya—in the main chamber and observed as the insects flew down the tubes towards one nylon or the other.

By far the most alluring target for Aedes aegypti was Subject 33, who was four times more attractive to the mosquitoes than the next most-attractive study participant, and an astounding 100 times more appealing than the least attractive, Subject 19.

The samples in the trials were de-identified, so the experimenters didn’t know which participant had worn which nylon. Still, they would notice that something unusual was afoot in any trial involving Subject 33, because insects would swarm toward that sample. “It would be obvious within a few seconds of starting the assay,” says De Obaldia. “It’s the type of thing that gets me really excited as a scientist. This is something real. This is not splitting hairs. This is a huge effect.”

The participants were sorted into high and low attractors, and then the scientists set out to determine what differentiated them. They used chemical analysis techniques to identify 50 molecular compounds that were elevated in the sebum (a moisturizing barrier on the skin) of the high-attracting participants. From there, they discovered that mosquito magnets produced carboxylic acids at much higher levels than the less-attractive volunteers. These substances are in the sebum and are used by bacteria on our skin to produce our unique human body odor.

To confirm their findings, Vosshall’s team enrolled another 56 people for a validation study. Once again, Subject 33 was the most alluring, and stayed so over time.

“Some subjects were in the study for several years, and we saw that if they were a mosquito magnet, they remained a mosquito magnet,” says De Obaldia. “Many things could have changed about the subject or their behaviors over that time, but this was a very stable property of the person.”

Even knockouts find us

Humans produce mainly two classes of odors that mosquitoes detect with two different sets of odor receptors: Orco and IR receptors. To see if they could engineer mosquitoes unable to spot humans, the researchers created mutants that were missing one or both of the receptors. Orco mutants remained attracted to humans and were able to distinguish between mosquito magnets and low attractors, while IR mutants lost their attraction to humans to a varying degree, but still retained the ability to find us.

These were not the results the scientists were hoping for. “The goal was a mosquito that would lose all attraction to people, or a mosquito that had a weakened attraction to everybody and couldn’t discriminate Subject 19 from Subject 33. That would be tremendous,” Vosshall says, because it could lead to the development of more effective mosquito repellents. “And yet that was not what we saw. It was frustrating.”

These results complement one of Vosshall’s recent studies, also published in Cell, which revealed the redundancy of Aedes aegypti’s exquisitely complex olfactory system. It’s a failsafe that the female mosquito relies on to live and reproduce. Without blood, she can’t do either. That’s why “she has a backup plan and a backup plan and a backup plan and is tuned to these differences in the skin chemistry of the people she goes after,” Vosshall says.

The apparent unbreakability of the mosquito scent tracker makes it difficult to envision a future where we’re not the number-one meal on the menu. But one potential avenue is to manipulate our skin microbiomes. It is possible that slathering the skin of a high-appeal person like Subject 33 with sebum and skin bacteria from the skin of a low-appeal person like Subject 19 could provide a mosquito-masking effect.

“We haven’t done that experiment,” Vosshall notes. “That’s a hard experiment. But if that were to work, then you could imagine that by having a dietary or microbiome intervention where you put bacteria on the skin that are able to somehow change how they interact with the sebum, then you could convert someone like Subject 33 into a Subject 19. But that’s all very speculative.”

She and her colleagues hope this paper will inspire researchers to test other mosquito species, including in the genus Anopheles, which spreads malaria, adds Vosshall: “I think it would be really, really cool to figure out if this is a universal effect.”

Reference: “Differential mosquito attraction to humans is associated with skin-derived carboxylic acid levels” by Maria Elena De Obaldia, Takeshi Morita, Laura C. Dedmon, Daniel J. Boehmler, Caroline S. Jiang, Emely V. Zeledon, Justin R. Cross and Leslie B. Vosshall, 18 October 2022, Cell.
DOI: 10.1016/j.cell.2022.09.034

35 Comments on "Scientists Discover Why Some People Are Mosquito Magnets"

  1. I bet I could outdo Subject 33. I live in a high and dry area, no swamps, wetlands or anything like that in mid-Atlantic. During mosquito season I can’t stay outside unprotected for a minute. The mosquitoes swarm and bite me continuously, and I mean dozens of bites non-stop. Now I wear all long clothing pants(blue denim) and shirts(charcoal), gloves, and brim hat(canvas) with a mosquito net that drapes to my clavicle and gets pulled snug by a draw cord, no exposed flesh. That setup works well, no bites whatsoever, but it does get uncomfortably warm.

  2. Great article. Thank you for not putting a clickbait title, but an accurate and interesting one, that was described in detail in the article.

  3. So interesting! I am a bait magnet for mosquitoes, have been my whole life. I am bit right through my clothing, so it doesn’t matter what I wear. Products with deet are useless. Wherever the spray doesn’t coat, the mosquitoes will find it and I will have bites. The bites swell up, excrete a clear fluid and itch horribly for days. Ive never ever enjoyed a summer in my 50 years, and I attribute it to the bites.

  4. I am not a scientist. Far from it. But this article makes me want to try the new product Lume. In the commercial, the lady urges you to apply it to your butt cheeks to keep odor away. Wondering if it’s formulated to react with the exact property in sebum that they are talking about here.

  5. Try changing the diet a bit. I have found that if I eat a lot of very spicy peppers that mosquitoes do not attack me nearly as much as otherwise. 6 habaneros a day seems to be a level that produces results for me.

  6. Sounds like this could be used to design more effective mosquito baits/traps.

  7. This is all driven by a virus that lives in Mosquito’s. You get it from your first bite ever. If your immune system resist this Virus, then your blood is the wrong kind. If it continues to live in you then you are the preferred meal. Every living thing on the planet owes its evolution to Viruses. Humans are the peak of evolution for a Virus. We are a Virus, ( as defined by science.). Our only unconscious goal is to get off this world and infect another world, so the process can be repeated.

  8. I knew that something is different about me.. in the same house I would get 11 mosquito bites and my siblings won’t get any.. same house.. same room..

  9. Great but practically what is causing this attraction? Is it that the person is super healthy? Super unhealthy? etc

  10. I could be 19.i live in GA and I doubt I get more than 5 bites all season. I’ve actually seen mosquitos leave me to go to someone near me.

  11. Rachel Cosgrove | October 24, 2022 at 10:47 am | Reply

    I am probably related to subject #33 in this study, as well as my daughter. I would like to know if there is a correlation between people like us who are highly attractive to mosquitoes also being highly attractive to ticks and chiggers as well? Another query, does getting bit by any or all of these blood seeking insects multiple times over many years change your blood chemistry?
    Having moved out here to Northwest Arkansas 20 years ago from the Pacific Northwest, Tillamook County, Oregon I have endured my quota of insect bites for a lifetime. So far, the only relief from this yearly onslaught I have found since I am an avid outdoors and wilderness enthusiast is DEET. I and undoubtedly thousands of others like me patiently await another less toxic remedy for warding off bug bites. Thank you for your diligence and work so far.

  12. My wife is subject 33. A mosquito in a room or open will find her and bite her even if an inch of her skin is exposed. On the other hand they don’t like me even if I am next to her with no patch on me. I think I am subject 19.

  13. “It’s can be impossible…”
    Really bad first sentence.

  14. So im 28 and live in Massachusetts and very similar to everyone here complaining of how they live in a cuty area and is still eaten alive…mr me 2 here and no matter what i do i get bit… now i know for a fact i have a distinct smell as my wife and many exs have said this ..i also can tell if something is mine just by smelling it. ..not a bad smell or dirty i just literally have my own human colgne lol ..after a shower .i am clean but again have my own smell Nd can see where that effects the mosquitoes. So this actually made alot of sense…someone needs to figure out how to eradicate the mosquitoe in general

  15. There could be two female mosquito’s left in all of North America.. one would find me and the other would find my mom to feed. We share the same blood type. My father could be in a swarm of female mosquito’s and not get touched. He has a different blood type. Me and my mother share the blood type only 4 percent of the population has. I’m sticking with the blood type theory…

  16. Hey 10th man… You are a pure inspiration to motivational speakers vs. Depression everywhere! Your rant has inspired me to have more intercourse, and try and contract every virus humanly possible… since we are a virus to begin with. I didn’t realize the first virus spawned from a living cell. I hope unconsciously mosquitos follow us to these other planets we inhabit and infect. That way we can keep the cycle going! First the milky way.. then the solar system !!! The Skys the limit bud!!! Or in this case I guess it isn’t!!! Nice rant bud lol.

  17. I love the summer months, but I get eaten alive! Only me! Has been like this my whole life. It is painful and incredibly disheartening. I have tried everything and NOTHING works! Please continue the research!!!

  18. I could easily be 19. Mosquitoes land on me but don’t bite. I’ve had very few bites in my life.

  19. I walk outside during mosquito season, they yell “lunch is served.” I have a cousin that has never had any kind of bite or sting. The major university research team were she lives, requests that she donate blood for them to look for differentials (their words).

  20. I knew what they took 3 years to find out 20 years ago, seriously?

    • Bigjim, when you discovered this 20 years ago did you publish an article so that others could benefit from your scientific findings? Would love to read it.

  21. I seem to be more attractive to these little ankle-biters than to the mosquitoes of old. Can’t go outdoors after dark at all without getting bit.

    I had one track me down & bite me several times a few days ago in the middle of the day & even had one track me down in Home Depot a week or so ago.

    For those of you who get bit try the “spoon” treatment. It works well for me.

  22. I bet that there is a relationship between a bite and the depth of a vein. Additionally, I bet that mosquitos also have superb hearing, therefore able to locate a vein without a GPS.

  23. Before the mosquitos season I take vitamin B12 and it really works as a mosquitos repellent.

  24. Over the age of 30 | October 24, 2022 at 8:18 pm | Reply

    I had a nursing instructor who had a brother who was doing research on why people get bitten by mosquitoes. She told me LACK OF Vitamin B-6! So one summer I had over 100 bites on one leg and the mosquitoe repellent doesn’t work for me -At ALL! The next summer I took 100 mg of B-6 daily and I only had 5 bites that summer! The only thing is that you will pee more. Children take 50mg daily. I still freak out when I see a mosquito!!

  25. As a mosquito magnet myself, this article was so very enlighting. Thank you for taking the time to study and share such a mysterious topic.

  26. If there were only “eight participants” in the initial study, how was there a subject 33? Typo?

  27. I used to be a mosquito magnet when I was younger, not so much anymore. I think the change had a lot to do with diet and lifestyle changes I made over the years. Adding garlic to your diet definitely helps.

  28. In 1992 I battled Testicular Cancer. Back then the treatment included high doses of radiation in my lower Pelvis and abdominal area. I received treatments daily for a month. There were a lot of not fun side effects, but the Silver lining was that for about 2 years Mosquitos wanted nothing to do with me. The first time I noticed was at a cookout with friends and the mosquitos were off the charts, yet none were biting me. We literally experimented at one point with me and 3 friends sitting out. The three were getting bitten and slapping them away. They didn’t even land on me. It was pretty amazing, but it had to be the radiation. I was told that it takes at least 2 years for the radiation leaves the body.

  29. Cool article and all, (now this isn’t the writers fault) but it’s quite inhumane and just, wrong on so many levels I feel that the scientists are using the information and mutating a mosquito that won’t bite humans. I get wanting to bring back an extinct species we killed off, even dinosaurs and wooly mammoths (although creating them just to shove em in a zoo seems unfair to them,but that’s off topic) but changing an animal that’s already thriving fine? Not ok, yes bites sick, yes they cause problems, but work on repellents instead! Creating a ‘new broken mosquito’ is worse then accidentally bringing an invasive species somewhere. There’s just no need! Mosquito’s despite being a real pain are needed in ecosystems, they feed birds, and other stuff too, hopefully- researching ways to deter then from us is fine, but mutating like that? In the words of Jeff Goldblum “we went so far to see if we could, you didn’t stop to think weather you should.”

  30. 35yo Male born and raised in Nacogdoches, TX. I too must be a carboxylic acid production factory. While it is true that this neck of the deep East Texas Pine Belt is rather humid and swarming with mosquitoes, I definitely receive a greater quantity of bites much more frequently than most people that I know here. Within a 20 minute window I generally receive 10-15 bites during peak season (while pacing, shaking limbs, etc. in an attempt to keep them from being able to land on me) while someone standing still next to me might receive 1 or 2 bites. They constantly buzz my ears and pass through my gaze before disappearing into the void anytime I’m outside. If I’m doing any sort of physical activity causing me to perspire, the numbers go up. As I’m standing on the deck at my mother’s house typing this, one buzzed my face…in October! I should add, for research purposes, my late father suffered from the same affliction which could suggest genetic inheritance perhaps. Please continue this line of research for all of the high carboxylic acid producers out there. We’re counting on you!!

  31. I used to be a mosquito magnet but that totally changed after I found out I’m lactose intolerant and stopped using dairy products. In 26 years I’ve been stung less (about seven or eight times) than in some single nights when I was still using dairy products.
    The change is significant but I’ve never found an explanation for this.

  32. Great article! Hopefully one day they figure this out, as I’m the poor bugger complaining all weekend while my mates are like “what mosquitos?”… Yeah- you’re welcome, hahaha!

  33. Heavensprincess | October 30, 2022 at 9:43 pm | Reply

    Not defined by man but God.

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