If malaria can be transmitted through a mosquito’s bite, why not HIV?

- asks Injy from New York

A mosquito prepares to feast on a human host. [Credit: Matti Parkkonen]
By | Posted December 17, 2007
Posted in: Ever Wondered?, Health
Tags: , , ,

Slap! Another mosquito! I try to resist the urge to scratch, but it would be easier to refuse a glass of water on a 110-degree day. I scratch, and oh, glorious relief! The feeling is just momentary, though, because here comes that hot sensation, and now my skin is swelling into a hideous red bump. Who knows what disease that thing could be carrying? At least I can be sure it isn’t HIV.

Scientists have pretty much ruled out the possibility that mosquitoes can spread the virus that causes AIDS. No documented case of HIV has ever been linked to the hated bloodsucker. While lack of evidence cannot by itself disprove a hypothesis, the chances of a mosquito transmitting HIV are so slim that the idea has faded out of scientific discussion as researchers face the real challenges of the immense predicament of AIDS.

However, when scientists were first learning about HIV, the insect transmission question was yet another unknown about the new disease. Some experiments and unexplained cases in the 1980s led to finger-pointing at mosquitoes, although scientists already had strong doubts that insects could transmit the disease.

In 1987, the now-defunct U.S. Office of Technology Assessment held a workshop to address concerns about a possible HIV threat from mosquitoes, bedbugs, ticks and cockroaches. Besides room for “a rare and unusual event” of possible insect transmission, the report states that it is almost impossible for the insects to pass along HIV.

The discussion has almost fizzled out, although a few investigations scattered over the years have continued to look for connections between HIV transmission and insects such as bedbugs and flies. In 2006, the United States Army Center for Health Promotion and Preventive Medicine issued a definitive report that outlined why there is no reason to worry about contracting HIV from a mosquito bite.

But why can’t you get HIV from a mosquito when it’s clearly the culprit in malaria, yellow fever and dengue fever? It’s all about the bug. There are two methods by which bloodsucking insects typically transmit disease: the biological method and the mechanical method.

The biological route is how malaria infects more than half a billion people each year. Its disease agent, the Plasmodium parasite, relies on the mosquito as a go-between to settle in human hosts.

Every mosquito bite involves a female mosquito looking for a blood meal to nourish her eggs. She injects saliva to keep the blood from clotting, and an allergic reaction to the saliva makes our skin annoyingly itchy and red after the bite. If the mama mosquito happens to bite a malaria-infected person, she ingests the parasites, which end up invading her cells and replicating. They then migrate to the salivary glands from where they can infect another human host in her next bite.

If the blood that she sucks up contains HIV, though, the virus can’t follow the same path as the malaria parasite. Instead of multiplying and eventually heading for the salivary glands, the viruses get digested, and meet their death in the insect’s gut.

The mechanical method is the other way for bloodsucking insects to pass along disease. Suppose a feeding mosquito is slapped away but is still hungry. Since insects don’t use napkins, blood remains on its mouthparts as it flies over to bite another victim. Theoretically, if Victim 1 had HIV circulating in his bloodstream, some could end up in Victim 2.

However, the probability of the transaction is almost zero. For one thing, the mosquito needs a healthy victim within quick buzzing distance of the HIV-positive one. Even in these conditions, the mosquito’s eating habits and the nature of HIV’s presence in the bloodstream still make it difficult to pick up viruses to transmit.

In a typical meal, a mosquito eats just a thousandth to a hundredth of a milliliter out of the average person’s 5.5 liters of blood. That’s like drinking a two-liter soda bottle of water out of an Olympic-sized pool.

From its tiny snack, the mosquito has hardly a chance of ingesting HIV. While the amount of the virus in blood varies from a few dozen to several hundred thousand viruses per milliliter, usually the levels are low. Blood left on the sloppy mosquito’s mouth is highly unlikely to have any HIV in it. If the mosquito bit someone with 1,000 viruses per milliliter, for example, there would be a 1 in 10 million chance of injecting just one virus body into another victim.

By now, scientists have a clear understanding of the ways HIV is spread, and insects are not one of them. With HIV’s estimated annual cost of around $20 billion and immeasurable effects on its victims, we’re lucky that the pesky mosquito’s bite isn’t another weapon in the disease’s arsenal.

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  1. A most interesting article, but I am still not 100% convinced. Research shows that although it is NOT completely impossible, contracting AIDS from a mosquito or any other bug is extremely unlikely. If there is even a minute chance that this could happen, wouldn’t the risk be multiplied many fold if you were working in a poorly funded AIDS hospital in the Tropics, for example? How about getting a fresh HIV infected mosquito squished in your eye, bypassing the normal transmission process research has focused on? Until I get more conclusive evidence, I will avoid warm tropical vacations and just stick to vacationing in Siberia!

    Patrick, December 18, 2007 at 8:01 am
  2. I’ve never understood why AIDS victims/patients aren’t quarantined from the rest of the population as was the custom in other infectuous diseases in the past. Had that been done in the very beginning there would not be an epidemic now that is out of control. Is this our way of controlling the population density on this planet by allowing sexually transmitted diseases as this and others to perpetuate for fear of offending sub-populations. It makes more sense to isolate and treat the infection and prevent the spreading than allow it to propagate unchecked because it’s a “social disease”. What is the wisdom (?) behind current treatment plans? I realize it’s too late to do that now, but why wasn’t it done back when it was first isolated by doctors and scientists in the early 1980s? Enkighten me.

    Robert, December 31, 2007 at 9:44 am
  3. What a well written article! But I do agree with Patrick. I’m not 100% convinced. I did first log on here so I could read about it for some extra credit in my science class, but I ended up learning up some very neat facts! Thanks for posting. :)

    Sarah, April 23, 2008 at 4:53 pm
  4. I agree with most of your comments. Scientists claim there have not been any reported incidents but..how many people truly go and get tested after being bitten by a mosquito for it to even be reported in the first place. They then argue that if it(transmission by mosquitoes) was the case then there would be a higher infection rate found in children..Again how many physicians even suggest HIV testing for children? Its a test that usually isnt even run unless the doc thinks the patient is /was at some risk..And finally, countries with high rates of malaria i.e Africa, tropical regions, etc also have higher rates of infection among all age groups..coincidence? you be the judge.

    Christopher, June 11, 2008 at 6:34 pm
  5. but if u had sex with a mosquito that had HIV, would you get it then?

    nmiosdhfkj, July 3, 2008 at 5:35 pm
  6. Interesting article, beautiful word play Nathalie, but im not convinced at all.
    In the first case, she said that the HIV would get digested after the HIV infected blood was sucked by the mosquito, and the virus would supposedly die. But i would like to remind Ms. Peretsman, the author, that viruses are disputably non-living organisms, ie they could not posssibly be killed if they were never alive.
    Same goes for the second case, if the blood containing HIV stays on the mosquitoes mouth, the virus becomes dormant, not dead. Thus no matter how long it would take for the mosquitoes appettite to return, the HIV possessing blood that remained on the suckers would, all things remaining equal, reach the next meal.
    Viruses do not die in the atmosphere, they merely go to sleep.

    Jason Muhande, July 12, 2008 at 11:13 pm
  7. I feel the need to post as Mr. Muhande and others seem to be rather confused. Perhaps the author should not have chosen to say the virus “meet[s its] death,” but rather that it becomes inactivated, destroyed, or uninfectious, once it reaches the mosquito’s gut. However, a virus like HIV, which is extremely fragile, does indeed “die,” or become inactivated/uninfectious rapidly upon exposure to the atmosphere. HIV does not “go to sleep” or become “dormant” in the atmosphere.
    Those interested in viruses that go to “sleep” in a molecular manner of speaking, might like to familiarize themselves with the concept of viral latency – of which HIV does take part, but only in certain cells of the body, and not on mosquito mouthparts!

    Katie, November 8, 2008 at 10:26 pm
  8. i accept.but can you tell me which enzyme digest hiv,tell me the mechanism ,how the hiv gets destroyed.

    prathiba, December 3, 2008 at 6:37 am
  9. im on this site because im worried. went to the park today with my kids and saw a person whom well known has hiv. there was a mosquito that bit this person and then bit my 3 month old baby immediately after. it happened so fast i couldnt do anything about it. what now?

    WORRIED, April 15, 2009 at 10:36 pm
  10. Today I killed a mosquito biting my hand. Then I got some blood on my hand from the mosquito. If the blood came from a HIV infected person the mosquito had been biting recently, couldn’t I then get the virus via the “opening” in my hand created by the mosquito? Or would the virus be deactivated/”dead” inside the mosquito? And how long can the virus “survive” inside the mosquito? Seconds, minutes, or hours?

    Lars Ivar, May 23, 2009 at 5:01 am
  11. Robert, your posting is the MOST unethical, inhumane thing that I have heard in a long time.

    Paul, July 18, 2009 at 3:46 pm
  12. Prop 64 tried your horrible idea. It failed thank God.

    http://lyndonlarouchewatch.org/aids.htm

    Why don’t we quaranteen stupid people, racists, those who think healthcare for all is “too expensive”, and my personal favorite those who go straight to cutting education to balance budgets. Is the goal to have sick, and stupid Americans? We have that now, look in the mirror!

    A word on our “financial crisis”. Instead of coddling the “job creators” tie their tax rate to the unemployment rate. Low unemployment would get them low taxes. High unemployment would be grounds for clawing back the money they would sit on by raising their taxes to an insufferable level.

    Genius if I don’t say so myself

    LaRoushe tried, June 12, 2011 at 2:47 pm
  13. Right on xyz

    I remember that campaign, spread panic not AIDS. His cry- PANIC – Prevent Aids Now Initiative Commitee. http://www.google.com/m/url?ei=kxn1TfifEuGjiAKD79WhAw&q=http://www.democraticunderground.com/discuss/duboard.php?az%3Dview_all%26address%3D389x1740708&ved=0CBYQFjAA&usg=AFQjCNEmcLsD9IjOzKj5Bq2-w4xWdy6fow

    I agree, it’s infected minds that are truly dangerous… They tend to self quaranteen in the GOP

    The tax comment is good but misplaced, and you did not reference Robert. Thanks for posting, there is a certain etiquette.

    Shutup Robert you dummy, June 12, 2011 at 3:01 pm
  14. I became very worried after my cousin, who is HIV positive and I slept on the same bed and under the same mosquito net. I woke up the next morning and saw dozens of mosquitoes with their stomachs filled with blood trapped in the net. They were trapped after passing through a hole in the net.
    What is the possibility for me contracting HIV in that manner? I an really anxious to know at this time.

    Millisa.

    Millisa, July 23, 2011 at 9:06 pm
  15. My cousin is affected by HIV, who came to our home and we(our family) talking with him for about 2.5 hours in evening, having more mosquitoes at that time.We are sitting near and around him.If there is any chances to get affected by HIV. Am really worried about me and my family members.

    Monika, October 30, 2011 at 1:48 am
  16. What if a large no of HIV mosquitoes are taken and then cooked (cooked well). Would eating them as a snack or a tea-dip cookie make me HIV infected? How high temperatures can the HIV virus remain alive at? What if we eat the meat of a goat that was bitten by a HIV mosquito? Or what if a goat bitten by a HIV mosquito licks my hand or face?

    Mosquito Cooker, December 7, 2011 at 8:15 am
  17. Since the probability of a mosquito transmitting the HIV virus is almost zero, we have nothing to fear for now. But let us beware………AIDS IS REAL

    T. Danso (Ghana), August 17, 2012 at 7:52 am
  18. please goverment be seriouse about this (hiv) becouse 2 of my family member are affected now and we are from poor family we did have mouch money for the treatment. We always strougle looking for a food that we will eat

    abdullahi, November 17, 2012 at 9:48 am
  19. I agree with Pratiba. If the so-called “biological process” detroys the HIV through digestion by the activity of enzymes, (in other words, mosquito enzymes “kill” HIV) then, the enzyme can be an HIV/AIDS drug if it’s “injectected” into an HIV-infected human body! I doubt if the mosquito enzyme can be “poisonous” to the HIV patient (remember: a mosquito only injects its saliva when it bites a person in a way to lubricate its “meal” before consuming, and this saliva is not harmful to the feasted victim – worse if it has not mealed blood from a malaria infected person for the past few days).

    So, why don’t Scientists/Doctors/Researchers, whichever name might be, study the chemical composition of this mosquito enzyme from its saliva, and refurmulate it artificially to form an HIV/AIDS drug? Hormones Progesterone and Oestrogen have been artificially formulated to form cotraceptive drugs. If they are taken by women under a prescription, they prevent ovulation to take place in the uterus, because there would be a “faked pregnancy” in the woman’s womb, thus, the ovaries do release any ovum(egg) for as long as the “hormone” is still present in the body. Scientists had discovered that while a woman is pregnant, a certain hormone is produced in her body, and this hormone “signals” the ovaries not to carry out any further ovulation duringl pregnancy. In this way, the artificial hormone (family planing pill or injection) works likewise.

    Back to the AIDS drug, they could initiate this simple experiment in a chemical laboratory, and then inject the “medicine” into an HIV-infected person. If the results are positive, then this simple experiment would now be industrialised into XYZ HIV/AIDS Drug Industries (PTY) LTD! This Factory, I tell you, would generate thousands of billions, if not trillions of dollars! Yes. Because this drug would outphase the prevailing ARVs!

    If this experiment is by no means feasible, then the hypothesis that mosquitoes DO NOT transmit HIV/AIDS from one person to another becomes null and void!

    G. Moyana

    G. Moyana, November 28, 2012 at 4:26 pm
  20. The HIV virus survive only in human being blood but not in a Mosquito body! I think Can Mosquito Can be Also cures to HIV/AIDS because
    What is that secrete killed HIV virus in mosquito
    Beside just digested, if other disease survive in mosquito like malaria transmission why not hiv! Why don’t Malaria don’t get digested
    Too because to me they all viruses!

    Denzil Mukuma, December 3, 2012 at 8:33 pm
  21. my question is ”do mosquitoes succeed in ingesting white blood cells which are much more bigger than R.B.Cs in size and less numerous?”

    yvan david, December 5, 2012 at 10:10 am
  22. It means , this kind of mechanism in Mosquito has the cure of this deadly disease..Isn’t ? can anybody answer ?

    Manoj, December 22, 2012 at 4:31 am
  23. tell me if the mosquitoes have the ability to kill hiv from thier bodies why can they expirement or analyze it in test

    benjo, February 8, 2013 at 5:36 am
  24. WHY WE CAN DO ALBUMIN AND GLOBULIN IN LFT REST.

    BUNTY, February 9, 2013 at 4:09 pm
  25. WHY WE CAN DO A/G RATIO IN LFT

    BUNTY, February 9, 2013 at 4:09 pm
  26. can we destoy the hiv virus in human body by knowing the process of the digetion of hiv virus in mosquito?

    periyanshulal, February 10, 2013 at 12:29 am
  27. Ican’t agree 100% to the fact that HIV can’t transmit through mosquitobites.

    If the digestive enzyme or the anticoagulant component inside the mosquito’s saliva, why can’t it be developed as a drug of choice to treat HIV.

    Elsa Sebastian, February 14, 2013 at 1:52 am
  28. If the digestive enzyme or the anticoagulant component inside the mosquito’s saliva kills the HIV virus, why can’t it be developed as a drug of choice to treat HIV.

    Elsa Sebastian, February 14, 2013 at 1:57 am
  29. several questions have been asked, what burders me most is, if a mosquito impregnated with blood meals was trying to escape from its host and making an atempt to kill it, one kills it directly on the injury he had earliar sustained, what then is the fate of such an innocent victim?

    gbasylee, February 17, 2013 at 1:02 pm
  30. mind us, this host harbours full grown aids. please i am curious!!!

    gbasylee, February 17, 2013 at 1:05 pm
  31. As the article itself says, you cannot definitively prove that transmission from mosquitos cannot occur due to lack of field cases.

    The real question is, is there a biological or physical basis for the blocking of transmission from mosquitos?

    The answer is, NO THERE ISN’T.

    There have been recent cases in Florida of Denghe fever being transmitted from mosquitos. In fact, if HIV can be transferred via blood, then any medium that carries blood from one human to another can in theory transmit HIV.

    It always amazes me as to the lengths people will go to make definitive claims in the absense of facts. It is like the “consensus” argument, which has no place in science.

    Alessio Ventura, September 18, 2014 at 2:05 pm
  32. Folks, nobody has even performed the most basic of validation tests.

    NO LAB or person has subjected HIV-infected persons to mosquito bites in a controlled setting, and performed the following:

    1) Assembled two groups of men in a controlled setting. One group is known to be HIV infected and one group is known to be HIV-free
    2) Gathered HIV-free mosquitos, verified via blood testing
    3) Released the Non-HIV mosquitos into the ontrolled environment of HIV-infected men
    4) Extracted blood from the mosquitos and determined if HIV is present or not
    5) Released the Non-HIV mosquitos to a non-HIV group of men so that they would bite the men
    6) Extracted blood from the non-HIV mosquitos and men and verified the existence or lack of existence of HIV in the blood

    Repeated the same experiment with a control group of Non-HIV mosquitos and Non-HIV men.

    This test would be repeated 10 times and the results tabulated.

    If in each run of the experiment just one Non-HIV mosquito or one Non-HIV man acquires the HIV virus, then one can conclude with certainty that you can transmit HIV ia a mosquito.

    But guess what, people are too afraid to perform these tests because of the political repercussions of the results. Let’s face it, the current governments are into non-disparagement of certain groups, such as intravenous IV users and homosexual men. Positive conirmation of HIV transmission via mosquitos could cause social unrest and have real implications for office holders. What a shame.

    Alessio Ventura, September 18, 2014 at 3:06 pm
  33. Very interesting comments. I wonder if the author of the article (or any other person with knowledge of this topic) could attempt to answer to the questions posed. I take note that the article was posted 7 years ago, yet we continue to lack answers

    cya, November 5, 2014 at 12:33 am
  34. Am from UK I give thank to a great doctor who help me out of my illness I was very sick I thank god who use this man to help, it started when i travel to Florida for visit there I meet a lady not knowing to me that she HIV positive I really like the lady because she was beautiful I always see her every moment I close my eye I went to tell her how I feel for her but I don’t know if she know that she HIV I went to bed with her I contacted the virus too when I get home for month my doctor come to check on me and he discover that I have HIV he was shock and tell me I was so confused and so surprised to hear that I was taking HIV drug to cure it for good a 2year I decided to look for cure them I meet this post on internet I contacted him for help… well DR.PALIPA proving to be a great man and he heal me.. According to him he said is the power of his

    johnson lilly, December 5, 2014 at 5:43 pm
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