# Mosquito bite = AIDS ? **URL:** \ **Category:** Factual Questions\ **Created:** [October 1, 2009, 10:57am UTC](https://boards.straightdope.com/t/mosquito-bite-aids/512223 "2009-10-01T10:57:03Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![BlooD\_FeatheR\_BG](https://avatars.discourse-cdn.com/v4/letter/b/54ee81/32.png) [@BlooD\_FeatheR\_BG](https://boards.straightdope.com/u/BlooD_FeatheR_BG)\ **Post date:** [October 1, 2009, 10:57am UTC](https://boards.straightdope.com/t/mosquito-bite-aids/512223/1 "2009-10-01T10:57:03Z")
There are 3 ways of getting AIDS: **1** \*Be born whith it \*(Your mother was already HIV-positiv durig the pregnancy). **2** _Have sex with HIV-positiv without condom._ **3** \*Get in some way HIV-positiv blood transfused in to your body \*(after severe wound, because of a drug habit, . . .) **My Question:** \*\*Can I get infected with HIV if a mosquito bites a HIV-infected sick person and after that bites me non-infected healthy person? Will I get AIDS? Why? Why not? P.S: Isn’t that scary how easy you might get infected, DAMN…\*\* ---
**Author:** ![Ferret\_Herder](https://avatars.discourse-cdn.com/v4/letter/f/e47774/32.png) [@Ferret\_Herder](https://boards.straightdope.com/u/Ferret_Herder)\ **Post date:** [October 1, 2009, 11:29am UTC](https://boards.straightdope.com/t/mosquito-bite-aids/512223/2 "2009-10-01T11:29:37Z")
Mosquitos can’t transmit HIV between humans. Among other reasons, the usual diseases they transmit are not digested by the mosquito and end up in their ‘saliva’ - [HIV is digested by them](http://www.rci.rutgers.edu/~insects/aids.htm). Other reasons why this doesn’t happen are listed in that article as well. ---
**Author:** ![Bricker](https://avatars.discourse-cdn.com/v4/letter/b/977dab/32.png) [@Bricker](https://boards.straightdope.com/u/Bricker)\ **Post date:** [October 1, 2009, 12:16pm UTC](https://boards.straightdope.com/t/mosquito-bite-aids/512223/3 "2009-10-01T12:16:26Z")
> [@Ferret\_Herder](#): > > Mosquitos can’t transmit HIV between humans. > > Among other reasons, the usual diseases they transmit are not digested by the mosquito and end up in their ‘saliva’ - [HIV is digested by them](http://www.rci.rutgers.edu/~insects/aids.htm). Other reasons why this doesn’t happen are listed in that article as well. I’m no expert, but it seems to me that the author made a leap between “extremely unlikely” and “not possible” that is not explained: > [@](#): > > Calculations with mosquitoes and HIV show that a mosquito that is interrupted while feeding on an HIV carrier circulating 1000 units of HIV has a 1:10 million probability of injecting a single unit of HIV to an AIDS-free recipient. In laymen’s terms, an AIDS-free individual would have to be bitten by 10 million mosquitoes that had begun feeding on an AIDS carrier to receive a single unit of HIV from contaminated mosquito mouthparts. Using the same calculations, crushing a fully engorged mosquito containing AIDS positive blood would still not begin to approach the levels needed to initiate infection. In short, mechanical transmission of AIDS by HIV-contaminated mosquitoes appears to be well beyond the limits of probability. Therefore, none of the theoretical mechanisms cited earlier appear to be possible for mosquito transmission of HIV. Now, one in ten million is pretty good odds. On the other hand, winning the Powerball lottery is something like 1 in 73 million, and there are people who have won the Powerball lottery. So the last sentence, which declares the event impossible, seems misleading. Certainly no one would say, “Therefore, winning the Powerball lottery does not appear to be possible.” It’s clear to me that getting HIV from a mosquito bites is far less likely than winning Powerball. But it’s not clear to me that it’s impossible. Am I missing something? ---
**Author:** ![The\_Librarian](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/the_librarian/32/402_2.png) [@The\_Librarian](https://boards.straightdope.com/u/The_Librarian)\ **Post date:** [October 1, 2009, 12:29pm UTC](https://boards.straightdope.com/t/mosquito-bite-aids/512223/4 "2009-10-01T12:29:47Z")
> [@Bricker](#): > > Am I missing something? I think the author is saying that the amount of virus transported by a mosquito isn’t enough to ‘intiate infection’. But the only kind of statistics I trust are those accompanied with calculations and the original dataset. Chances of 1 in 10 million are almost always bullshit. (except when it is the answer to the question ‘what are the odds of rolling a 6 nine times in a row?’) ---
**Author:** ![RealityChuck](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/realitychuck/32/195_2.png) [@RealityChuck](https://boards.straightdope.com/u/RealityChuck)\ **Post date:** [October 1, 2009, 12:36pm UTC](https://boards.straightdope.com/t/mosquito-bite-aids/512223/5 "2009-10-01T12:36:07Z")
But note the words “Among other reasons.” > [@](#): > > Mosquitoes Are Not Flying Hypodermic Needles > > Many people think of mosquitoes as tiny, flying hypodermic syringes, and if hypodermic needles can successfully transmit HIV from one individual to another then mosquitoes ought to be able to do the same. We have already seen that HIV-infected individuals do not circulate enough virus particles to result in infection by contamination. However, even if HIV-positive individuals did circulate high levels of virus, mosquitoes could not transmit the virus by the methods that are employed in used syringes. Most people have heard that mosquitoes regurgitate saliva before they feed, but are unaware that _the food canal and salivary canal are separate passageways in the mosquito._ (italics mine) Mosquitos inject an anticoagulant when biting you; that’s why their bites itch. When feeding, the blood goes into their mouth, not the gland secretes the anticoagulant. So there’s no direct connection between the injection and the feeding. Mosquito-borne diseases like malaria or yellow fever travel through the mosquito’s digestive system and into their salivary glands (and if they could have evolved to be injected from the mouth, they would have); AIDS has not developed this ability. ---
**Author:** ![Bricker](https://avatars.discourse-cdn.com/v4/letter/b/977dab/32.png) [@Bricker](https://boards.straightdope.com/u/Bricker)\ **Post date:** [October 1, 2009, 1:01pm UTC](https://boards.straightdope.com/t/mosquito-bite-aids/512223/6 "2009-10-01T13:01:42Z")
> [@RealityChuck](#): > > But note the words “Among other reasons.” > > Mosquitos inject an anticoagulant when biting you; that’s why their bites itch. When feeding, the blood goes into their mouth, not the gland secretes the anticoagulant. So there’s no direct connection between the injection and the feeding. > > Mosquito-borne diseases like malaria or yellow fever travel through the mosquito’s digestive system and into their salivary glands (and if they could have evolved to be injected from the mouth, they would have); AIDS has not developed this ability. That does not refute the third hypothetical transmission mechanism: > [@](#): > > The third theoretical mechanism also involves a mosquito that is interrupted while feeding on an HIV carrier and resumes the partial blood meal on a different individual. In this scenario, however, the AIDS-free host squashes the mosquito as it attempts to feed and smears HIV contaminated blood into the wound. In theory, any of the mosquito-borne viruses could be transmitted in this manner providing the host circulated sufficient virus particles to initiate re-infection by contamination. ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [October 1, 2009, 1:29pm UTC](https://boards.straightdope.com/t/mosquito-bite-aids/512223/7 "2009-10-01T13:29:36Z")
> [@Bricker](#): > > Now, one in ten million is pretty good odds. > > On the other hand, winning the Powerball lottery is something like 1 in 73 million, and there are people who have won the Powerball lottery. Consider also the remote chance that a mosquito which has recently fed on an AIDS carrier will bite _you_. I suspect the statistical probability of that occurring are comfortably higher than 1 in 10 million, so you’d end up with an overall probability of contracting AIDS via mosquito transmission of… well, a number that you’d write in scientific notation. That’s not even considering the less-than-1/1 statistical likelihood that the mosquito draws enough blood from the AIDS carrier to infect at all, which would be dependent on how long it remains attached and how much viral material is circulating in the carrier’s bloodstream. Close enough to impossible that you can reasonably call it impossible, in other words. ---
**Author:** ![Bricker](https://avatars.discourse-cdn.com/v4/letter/b/977dab/32.png) [@Bricker](https://boards.straightdope.com/u/Bricker)\ **Post date:** [October 1, 2009, 2:37pm UTC](https://boards.straightdope.com/t/mosquito-bite-aids/512223/8 "2009-10-01T14:37:50Z")
> [@Really\_Not\_All\_That\_Bright](#): > > Consider also the remote chance that a mosquito which has recently fed on an AIDS carrier will bite _you_. Surely that’s something we can quantify further, though? I mean, the odds of getting struck by lightning are vanishingly small. But why do we advise people not to take shelter under a tree during a thunderstorm? Isn’t it because next to a tall object during a thunderstorm, the odds of being struck by lightning are much higher? So I know that standing outside a cabin halfway between Nome and Juneau, the odds of getting bitten by a mosquito that has just bitten an HIV-positive person is scientific notation territory. But can we say the same thing about standing in the middle of an AIDS hospice picnic? > [@](#): > > That’s not even considering the less-than-1/1 statistical likelihood that the mosquito draws enough blood from the AIDS carrier to infect at all, which would be dependent on how long it remains attached and how much viral material is circulating in the carrier’s bloodstream. > > Close enough to impossible that you can reasonably call it impossible, in other words. Sure. The author does point out how, with HIV, it’s often the case that the bloodstream has comparatively little viral material. But “effectively impossible” means something different than “actually impossible.” Choosing to avoid attending that picnic because of the chance of getting infected by mosquito bite would be ridiculous, because the risk-benefit analysis comes down overwhelmingly on the side of no infection. I’m totally with that. So when someone says, “Close enough to impossible that you can reasonably call it impossible, in other words,” I think they’ve done a fair job of communicating the truth. Paradoxically, however, if someone were to describe the same event simply as “Impossible,” then I would not. ---
**Author:** ![pan1](https://avatars.discourse-cdn.com/v4/letter/p/e495f1/32.png) [@pan1](https://boards.straightdope.com/u/pan1)\ **Post date:** [October 1, 2009, 2:50pm UTC](https://boards.straightdope.com/t/mosquito-bite-aids/512223/9 "2009-10-01T14:50:42Z")
There are no documented cases of HIV transmitted via insect bite. For a disease thats been heavily investigated for almost 30 years, that says something. ---
**Author:** ![pan1](https://avatars.discourse-cdn.com/v4/letter/p/e495f1/32.png) [@pan1](https://boards.straightdope.com/u/pan1)\ **Post date:** [October 1, 2009, 2:59pm UTC](https://boards.straightdope.com/t/mosquito-bite-aids/512223/10 "2009-10-01T14:59:50Z")
PS. I wouldn’t call HIV “easy” to get. You actually have to try pretty darned hard. You don’t accidentally have unprotected sex. (Excluding Rape Victims from this statement) There are a number of things that have to go wrong to transmit HIV through a wound. The first of which is the HIV+ person getting a bleeder wound. The second is getting it into your body. Maybe you haven’t noticed but skin is water and air tight - You’d have to have a wound too. And Medical professionals are trained to avoid exchanging fluids with or between patients. Odds are very much against catching HIV without doing something stupid. (It happens to innocent, careful people through circumstances described above, but only rarely) Generally you have to do something foolish. Unprotected sex or sharing needles. And the latter is the most guaranteed method to transmit. The unprotected sex is still dangerous and should be avoided, too. Not Easy to get unless you’re a fool or ignorant. It’s not like an airborne cold or flu where you could just walk down the street too close to where a sick person exhaled. ---
**Author:** ![lazybratsche](https://avatars.discourse-cdn.com/v4/letter/l/ba8739/32.png) [@lazybratsche](https://boards.straightdope.com/u/lazybratsche)\ **Post date:** [October 1, 2009, 3:36pm UTC](https://boards.straightdope.com/t/mosquito-bite-aids/512223/11 "2009-10-01T15:36:09Z")
For that third hypothesis, it still seems extremely far fetched to me. It’s not like a mosquito bite leaves a huge gaping wound. I’ve never seen a mosquito bite that bleeds at all; more remarkable considering all of the anticoagulants that a mosquito uses. How long does the HIV virus even survive in a mosquito’s stomach? The cited article says that blood is entirely digested within a day or two, so that’s an upper bound, but I would guess that the relatively delicate HIV virus would survive far shorter than that. Now with a bit of data, from [this report from the Office of Technology Assessment](http://books.google.com/books?id=WBs9LrRvYowC&dq=hiv+tissue+culture+infectious+units&source=gbs_navlinks_s): Apparently a typical HIV patient has something like 10 tissue culture infectious units per mL of blood, though extreme cases have seen as high as 25,000 units/mL. If a mosquito is fed 10,000 to 100,000 units/mL, certain strains of HIV can survive for a few hours (but other strains don’t survive in any measurable amount). Apparently some tiny fraction of virus can survive for up to 48 hours if the mosquito eats 1 million units/mL. In the real world, I’d interpret that as saying that IF a mosquito bites a person with near record-setting viral load, AND IF you do you best to extract the virus within minutes, AND IF you inject the virus strait into your bloodstream, you’ll still have a tiny chance of being infected. Exposure via accidental needle stick has an infection rate around 0.3%, and for that sort of exposure the virus is only outside a human body for at most a few minutes, and it isn’t exposed to sunlight or digestive enzymes or any other number of things that will kill the HIV virus. The volume of blood transferred by accidental needle stick is also orders of magnitude bigger than what can possibly transferred by mosquito. There’s a lot more in that report, if anyone wants to read up and follow their cites. ---
**Author:** ![Valgard](https://avatars.discourse-cdn.com/v4/letter/v/7feea3/32.png) [@Valgard](https://boards.straightdope.com/u/Valgard)\ **Post date:** [October 1, 2009, 4:25pm UTC](https://boards.straightdope.com/t/mosquito-bite-aids/512223/12 "2009-10-01T16:25:59Z")
To the OP, if you google around looking for information on this you will probably get a lot of links leading back to the Lyndon Larouche folks. They’re a bunch of complete nutjobs who years ago here in California were trying to push the idea that people were catching AIDS from mosquito bites all the time (that’s not all of their insanity, just one thing they were saying). Just an FYI. ---
**Author:** ![Tamerlane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tamerlane/32/7602_2.png) [@Tamerlane](https://boards.straightdope.com/u/Tamerlane)\ **Post date:** [October 1, 2009, 4:49pm UTC](https://boards.straightdope.com/t/mosquito-bite-aids/512223/13 "2009-10-01T16:49:01Z")
> [@Bricker](#): > > So when someone says, “Close enough to impossible that you can reasonably call it impossible, in other words,” I think they’ve done a fair job of communicating the truth. Paradoxically, however, if someone were to describe the same event simply as “Impossible,” then I would not. Ugh. Lawyers. 😛 I say that with all due respect ;). ---
**Author:** ![Miller](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/miller/32/481_2.png) [@Miller](https://boards.straightdope.com/u/Miller)\ **Post date:** [October 1, 2009, 4:55pm UTC](https://boards.straightdope.com/t/mosquito-bite-aids/512223/14 "2009-10-01T16:55:27Z")
> [@Really\_Not\_All\_That\_Bright](#): > > Consider also the remote chance that a mosquito which has recently fed on an AIDS carrier will bite _you_. It’s not just that, though. Because a mosquito that feeds on an AIDS carrier isn’t going to bite anyone else: they’ve just eaten. So, first calculate the odds that the mosquito bites someone with AIDS. _Then_ calculate the odds that they are interrupted before they can finish, and are still hungry. _Then_ calculate the odds that they decide to land on you to finish their meal. If all of those odds line up, _then_ there’s a 1 in 10 million chance of catching the virus. I’m guessing we’re well into scientific notation territory by that point.