Differential mosquito attraction to humans is associated with skin acid levels
cell.com
cell.com
They started with only 64 individuals. Of those only ONE was found to be especially attractive to mosquitoes, and only TWO especially unattractive. They then used the scents from these three individuals, and 5 others who did not participate in the initial testing, for the following phases of research.
Also, of the 5 additional people, two were found to be especially attractive, and one unattractive. This is extremely inconsistent with the results from the first phase.
Now, they did a ton of work and show very interesting results. But these problems make all of their results very questionable in my mind.
Yes, followup research could shine more light on this to validate their results (or not), but I wish they would make less grand declarations about the meaningfulness of their results. I bet this is going to make the news around the world... and if it later turns out to be inaccurate, it's only going to further reduce the public's trust in science.
This is not an analysis of "what fraction of people are attractive to mosquitoes", it is about how mosquito attraction differs between people. You can make meaningful statistical claims about this with just two subjects (and lots of measurements, which they did - see e.g. Fig 1G).
I also don't understand how you complain about the insufficient sample size and then go on to claim the difference between two cohorts is "extremely inconsistent".
With just two subjects, there is a very high chance that the results of your testing are overly specific to those two subjects, and do not hold for most of the population.
With only 8 subjects, as in this study, that is still very true.
For example, people like the one person the mosquitos were extremely attracted to could be one in 10, one in 100 or one in a million. In the latter case, the findings are much, much less meaningful.
That's true even for the findings about specific genes affecting attraction. What if that one person is an extreme outlier and the mechanism causing the results isn't relevant for 99.9999% of the human population?
> Can you elaborate on which specific statistical claim you think they should not make?
For example, the claim that "Highly attractive people have higher levels of carboxylic acids on their skin" does not seem to be well enough backed by evidence in this case. If they wrote, "the one/three attractive people we tested had higher levels of carboxylic acids on their skin", I'd have no complaints.
I might be missing something, but do you not see additional evidence for this claim in the discussion around figure S4?
In my reading, the authors do go out of their way to point out that carboxylic acid presence is only one of possibly many more factors. (See also "Limitations of the study"). Most of that nuance is lost in the "highlights" section though, I would agree.
I wonder if diet has any impact on this. Anecdotally one of my childhood friends in boy scouts was a vegetarian and my goodness was he a mosquito magnet. I’ve always wondered if there was some relationship with what protein you eat and how attractive you are to these insects.
Edit: keep the anecdotes coming. I mean no judgement on any diet. I really just want to understand what makes these horrible insects bite people because, while I was born in Iowa, I spent most of my young adult life in Minnesota and wew that state has a lot of mosquitoes.
I am a massive mosquito magnet, and I was initially a proper t-rex eating meat every day for 25 years but in the last ten years I’ve been 99% Pescatarian (mostly just veggie but sometimes fish or seafood) and I’m still the same massive mosquito magnet.
My wife was her whole life Vegetarian and she is the opposite of me, not a mosquito magnet.
But no idea if it’s diet related as I cannot remember how it was before I switched diet; too long ago.
This has also given me an understanding as to why if you ever see any product reviews for DEET based mosquito repellent you'll inevitably see one or more people advocating some hippie tincture that's apparently better but has no terrible chemicals in it.
I always think there was probably a human mosquito meat shield nearby who was taking the hits for them.
A friend of mine was in the same situation - he was a magnet, his wife not. His explanation was - "She is so toxic, that they die if they bite her". Brave guy.
But that might also be because kid me played outside in the park in the evening/went camping etc., and if adult me is out in the evening it's usually sitting outside a bar.
The study did try to rule diet out though.
It’s crazy how fast it’s happened.
Once the mosquitos start spreading one of the many terrible diseases they can carry the government officials will finally act, after it’s too late to save the first victims of an avoidable problem.
Horrible quality of life issue that should be fixable if the government officials can get their act together soon!
https://us.biogents.com/aedes-albopictus-asian-tiger-mosquit...
How certain are we that it’s a difference in whether or not someone is bit by mosquitos vs. whether or not (or how) someone’s body reacts to a mosquito bite?
I am a mosquito magnet, but my skin also deals with other oddness on occasion, plus I’m moderately allergic to a number of things. So part of me feels that may have some (more?) to do with it vs. that I’m bitten more.
E.g. I’ll often find myself riddled with mosquito bites without even having realized I was being bitten. So I imagine it’s possible for non-magnets to also be bitten but just not have the same reaction.
Not so anecdotally: I get massive reactions from bites that last a long time (sometimes months).
For example: In my 20's I once went canoeing on the Russian river and drank all day. Since it was a hot day, I was pretty burnt out when my GF and I got back to our camp site late in the afternoon. Our site was probably about 200 yds from the river's edge and when we got back I pulled a sleeping bag out of the tent and laid down on it on the grass. I pretty much immediately fell asleep (drinking, heat) on top of the sleeping bag. I woke up a couple hours later after the sun had just set. I was covered in bites. For the next week or so I tried to count the bites and ended up settling on 107 mosquito bites! It took over 3 months for them to go away! Needless to say, I will never forget that experience and no one will convince me otherwise that I am not a mosquito magnet.
They also specifically call out that there are "low attractor" humans who simply don't generate as much of the carboxylic acid compounds that the mosquitos were attracted to, and who may still be bitten, but were not he preference.
People definitely react different to bites, though. I know plenty of people who don't really feel much of an itch, vs others for whom it's awful.
Mostly they don't even land on me, but I have watched when they do - the closest they get to biting is lowering their proboscis until it touches skin. Then they fly off.
I always assumed it had to do with skin odour, probably diet related. It's surprising that the science isn't more advanced on this considering how harmful/annoying mosquitos can be and how primitive the current countermeasures are.
https://pubmed.ncbi.nlm.nih.gov/20209056/ and https://pubmed.ncbi.nlm.nih.gov/12083361/
Really interesting, again super small sample size. It's just his girlfriend and him testing out who's more attractive using a lab experiment. I don't believe they were able to conclusively answer the question, even with the mosquitoes biting one person more than the other.
I had been thinking for a while, mosquitoes prefer certain smells, and use their olfactory senses to find targets.
Anecdotally, like others on the thread, I get bitten all the time in areas with mosquitoes, where my parents, others never did.