MOSQUITO AND AIDS

[sonawanes61]

if a mosquito bites an AIDS patient and again bites some other person then why do other person not get infected by AIDS?

[MrMistery]

i'm guessing they would, if there would be direct blood transfer. Unlike malaria, the AIDS virus does not need a mosquito to reproduce however

[sonawanes61]

i did not understood

[MrMistery]

if a mosquito were to transfer HIV-infected blood from one person to another it would indeed bring about AIDS in the second person. But this is not the way it is normally transmitted. Malaria, for instance, can only be transmitted through a mosquito bite.

[sonawanes61]

thts wht i m asking
why???????

[MichaelXY]

This From CDC

Can I get HIV from mosquitoes?

No. From the start of the HIV epidemic there has been concern about HIV transmission from biting and bloodsucking insects, such as mosquitoes. However, studies conducted by the CDC and elsewhere have shown no evidence of HIV transmission from mosquitoes or any other insects - even in areas where there are many cases of AIDS and large populations of mosquitoes. Lack of such outbreaks, despite intense efforts to detect them, supports the conclusion that HIV is not transmitted by insects.

http://www.cdc.gov/hiv/resources/qa/qa32.htm

This from Wiki on malaria

The parasite's primary (definitive) hosts and transmission vectors are female mosquitoes of the Anopheles genus. Young mosquitoes first ingest the malaria parasite by feeding on an infected human carrier and the infected Anopheles mosquitoes carry Plasmodium sporozoites in their salivary glands. A mosquito becomes infected when it takes a blood meal from an infected human. Once ingested, the parasite gametocytes taken up in the blood will further differentiate into male or female gametes and then fuse in the mosquito gut. This produces an ookinete that penetrates the gut lining and produces an oocyst in the gut wall. When the oocyst ruptures, it releases sporozoites that migrate through the mosquito's body to the salivary glands, where they are then ready to infect a new human host. This type of transmission is occasionally referred to as anterior station transfer.[43] The sporozoites are injected into the skin, alongside saliva, when the mosquito takes a subsequent blood meal.

http://en.wikipedia.org/wiki/Malaria

[MrMistery]

I am apparently wrong. I did say at the beginning that i never heard of such a case. However, i still don't see exactly why.

[Darby]

There are a couple of reasons -

First, HIV is not a very stable virus, and just being in the mosquito's digestive system would disrupt it.

Second, mosquitoes don't transfer blood from one victim to the next. Agents that use mosquitoes have to be able to get out of the mosquito's gut and into its salivary glands - they "spit" an anticoagulant saliva through their mouthparts when they start a bite. That's how malaria and West Nile virus work.

Because of the first problem, it's unlikely that HIV will transfer through any kind of biting insect, even ones with simpler transfer systems.

[MrMistery]

i was thinking of blood being left on the mosquito`s mouth, although that is highly improbable. And since the HIV virus does dye when exposed to air, i can see why it wouldn't occur.
Thanks.

[Darby]

The mosquito is pumping blood into its pharynx - I'm not even sure they have a mouth with a space blood could stay in.

[MrMistery]

the part that it stings you with, I'm not sure what that's called in English - that is what i was referring to when i said mouth

[Darby]

Yeah, the "straw" they use is actually several mouthparts brought together - there isn't really a permanent space in it.