# Relative risks of AIDS **URL:** \ **Category:** Factual Questions\ **Created:** [September 4, 2009, 2:29pm UTC](https://boards.straightdope.com/t/relative-risks-of-aids/508860 "2009-09-04T14:29:27Z")\ **Posts on this page:** 16\ **Page:** 2
**Author:** ![Alex\_Dubinsky](https://avatars.discourse-cdn.com/v4/letter/a/dbc845/32.png) [@Alex\_Dubinsky](https://boards.straightdope.com/u/Alex_Dubinsky)\ **Post date:** [September 6, 2009, 3:30pm UTC](https://boards.straightdope.com/t/relative-risks-of-aids/508860/21 "2009-09-06T15:30:56Z")
> [@Tamara+](#): > > 10 out of 10,000 chances of getting infected from penile intercourse? Why would anyone publicize this? Do you know how many people will read that and say hey theres a great chance I won’t get it? And those people reading this will get a glimpse of the truth. But they must now, must they 😛 “why would anyone publicize this” haha ---
**Author:** ![lobotomyboy63](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lobotomyboy63/32/2900_2.png) [@lobotomyboy63](https://boards.straightdope.com/u/lobotomyboy63)\ **Post date:** [September 6, 2009, 4:44pm UTC](https://boards.straightdope.com/t/relative-risks-of-aids/508860/22 "2009-09-06T16:44:57Z")
_AIDS is now a pandemic.[6] In 2007, it was estimated that 33.2 million people lived with the disease worldwide, and that AIDS killed an estimated 2.1 million people, including 330,000 children.[7] Over three-quarters of these deaths occurred in sub-Saharan Africa,[7] retarding economic growth and destroying human capital.[8]_ > **[HIV/AIDS](https://en.wikipedia.org/wiki/AIDS)** > > Infection with HIV (Human Immunodeficiency Virus), a retrovirus, can be managed with treatment but without treatment can lead to a spectrum of conditions including AIDS (Acquired ImmunoDeficiency Syndrome). > Effective treatment for HIV-positive people (people living with HIV) involves a life-long regimen of medicine to suppress the virus, making the viral load undetectable. There is not yet a vaccine nor a cure. An HIV-positive person on treatment can expect to live a normal life, and die... My understanding was that it’s running rampant in Africa and poorer areas like Haiti. Africa’s right at a billion people, so assuming 3/4 of the 33.2 million are in Africa, that’s about 25 million or 2.5%. One in 40, hmm, not a rare thing. My WAG is that they had less education about it and have more unprotected sex than most westerners do. ---
**Author:** ![JillGat](https://avatars.discourse-cdn.com/v4/letter/j/9fc29f/32.png) [@JillGat](https://boards.straightdope.com/u/JillGat)\ **Post date:** [September 7, 2009, 3:40am UTC](https://boards.straightdope.com/t/relative-risks-of-aids/508860/23 "2009-09-07T03:40:37Z")
There’s no way to give a specific, accurate statistic on any of those scenarios, obviously. That being said, a person who was very recently infected with HIV (in the last month or so) is more likely to transmit the virus to you (if you get their blood or semen into your bloodstream somehow) than someone who’s been living with HIV for a year or so. ---
**Author:** ![Noel\_Prosequi](https://avatars.discourse-cdn.com/v4/letter/n/b19c9b/32.png) [@Noel\_Prosequi](https://boards.straightdope.com/u/Noel_Prosequi)\ **Post date:** [September 7, 2009, 4:55am UTC](https://boards.straightdope.com/t/relative-risks-of-aids/508860/24 "2009-09-07T04:55:37Z")
One has to wonder about how they got those statistics. I gather some come from prostitutes who have reasonably reliable work records, but otherwise information about frequency of intercourse and partner numbers is, after the event, almost always going to be a WAG. This is so particularly where the estimates have to be given over a sufficiently long period to contain statistically significant numbers. It seems that HIV is less infectious than was first feared, at least in some populations, but I fear the numbers being munged about must have such wide margins of error as to be seriously unreliable. Statistics with an illusory air of precision are potentially worse than unhelpful. But I am open to having my mind changed. If anyone can show that the methodology is reliable, I am happy humbly to recant my dubiosity. ---
**Author:** ![JillGat](https://avatars.discourse-cdn.com/v4/letter/j/9fc29f/32.png) [@JillGat](https://boards.straightdope.com/u/JillGat)\ **Post date:** [September 9, 2009, 3:15am UTC](https://boards.straightdope.com/t/relative-risks-of-aids/508860/25 "2009-09-09T03:15:05Z")
This isn’t a roll of the dice, people. There are too many contributing factors to assign a % risk to getting HIV that fits every person’s scenario. I’ll tell you what, though; it’s not 100%, but you can cut down your risks a huge amount by doing the following: Only have unprotected sex with people who you know for a fact have recently tested HIV negative (yeah, yeah, window period, but still much, much better than not knowing their status at all). Don’t have sex with anonymous partners and try not to have sex with people who you think might have multiple or anonymous partners. If your partner is already HIV positive, use condoms and avoid any practices that are likely to make condoms break or to cause your blood or semen to mingle. If you or your partner tests positive for syphilis, don’t have sex until about a month after the infected person has been treated for syphilis and tested negative for HIV (syphilis in the picture can make HIV easier to get and the two diseases sometimes travel together). See? I didn’t even mention monogamy, condoms-every-time or abstinence. Those work too, but not everybody can do those things. Quit your rolling dice and magical thinking. ---
**Author:** ![panache45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/panache45/32/64_2.png) [@panache45](https://boards.straightdope.com/u/panache45)\ **Post date:** [September 9, 2009, 4:08am UTC](https://boards.straightdope.com/t/relative-risks-of-aids/508860/26 "2009-09-09T04:08:11Z")
> [@lobotomyboy63](#): > > _AIDS is now a pandemic.[6] In 2007, it was estimated that 33.2 million people lived with the disease worldwide, and that AIDS killed an estimated 2.1 million people, including 330,000 children.[7] Over three-quarters of these deaths occurred in sub-Saharan Africa,[7] retarding economic growth and destroying human capital.[8]_ > > [HIV/AIDS - Wikipedia](http://en.wikipedia.org/wiki/AIDS) > > My understanding was that it’s running rampant in Africa and poorer areas like Haiti. Africa’s right at a billion people, so assuming 3/4 of the 33.2 million are in Africa, that’s about 25 million or 2.5%. One in 40, hmm, not a rare thing. My WAG is that they had less education about it and have more unprotected sex than most westerners do. And the Pope didn’t help the situation, telling them to stop using condoms. ---
**Author:** ![AboutAsWeirdAsYouCanGet](https://avatars.discourse-cdn.com/v4/letter/a/22d042/32.png) [@AboutAsWeirdAsYouCanGet](https://boards.straightdope.com/u/AboutAsWeirdAsYouCanGet)\ **Post date:** [September 9, 2009, 4:23am UTC](https://boards.straightdope.com/t/relative-risks-of-aids/508860/27 "2009-09-09T04:23:49Z")
> [@](#): > > My WAG is that they had less education about it and have more unprotected sex than most westerners do. Ummmmm…I thought the AIDS epidemic in Africa was due to poor medical clinic conditions. Like medical supplies were so expensive that the docs reused them, and thus one infected person caused a HELL of a lot of problems. Saying that it was due to unprotected sex, almost sounds like you’re reinforcing the old stereotype that black men are very sexually promesticus. ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [September 9, 2009, 5:58am UTC](https://boards.straightdope.com/t/relative-risks-of-aids/508860/28 "2009-09-09T05:58:14Z")
Well, this points up the difference between ‘possible’ and ‘likely’ quite effectively. For example, it’s _possible_ to get HIV through kissing, assuming there is some way for blood to transfer during the kiss. It is not, however, altogether _likely_ for that to occur. Ditto handshakes, under the same circumstances. The fact remains that AIDS has been around since _at least_ 1959 and it has been in America since _at least_ 1981. ([This retrospective says it was out of Africa by 1971.](http://www.retrovirology.com/content/3/1/72)) We had no very clear idea about what caused it until 1983-1984. If it was as virulent as early reports imagined, it would have tore through the world like a wildfire through dry grass. ---
**Author:** ![Nicolas\_Bourbaki](https://avatars.discourse-cdn.com/v4/letter/n/ecc23a/32.png) [@Nicolas\_Bourbaki](https://boards.straightdope.com/u/Nicolas_Bourbaki)\ **Post date:** [September 9, 2009, 9:25pm UTC](https://boards.straightdope.com/t/relative-risks-of-aids/508860/29 "2009-09-09T21:25:36Z")
> [@Nametag](#): > > That’s incorrect. Heroin and other abused IV drugs are injected by first drawing in blood, allowing it to mix with the drug in the syringe, and then injecting the mixture into the vein. Some users will then draw blood back into the syringe and push it out again, to “rinse it out.” I don’t know nada about smack, and it’s been a long time since I saw _Trainspotting_, so mea culpa. But seriously, [what’s the motivation behind it](http://i530.photobucket.com/albums/dd345/mordant_carnival/why_would_you_do_that.jpg), and not just, yaknow, skip that step if you’re doing something as retarded as sharing needles? ---
**Author:** ![lobotomyboy63](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lobotomyboy63/32/2900_2.png) [@lobotomyboy63](https://boards.straightdope.com/u/lobotomyboy63)\ **Post date:** [September 9, 2009, 9:59pm UTC](https://boards.straightdope.com/t/relative-risks-of-aids/508860/30 "2009-09-09T21:59:32Z")
> [@AboutAsWeirdAsYouCanGet](#): > > Saying that it was due to unprotected sex, almost sounds like you’re reinforcing the old stereotype that black men are very sexually promesticus. I don’t think so. I can’t speak to what African cultures deem promiscuous and what they don’t, for one thing. And unprotected sex could result from condoms not being available or affordable in parts of Africa. Some may practice withdrawal or the rhythm method to avoid pregnancy but not realize that it doesn’t prevent transmission of STDs. If communication/education isn’t good, they may not have even realized the disease was out there and spreading, like we didn’t here in the US back in the early 1980s. ---
**Author:** ![The\_Great\_Philosopher](https://avatars.discourse-cdn.com/v4/letter/t/3ec8ea/32.png) [@The\_Great\_Philosopher](https://boards.straightdope.com/u/The_Great_Philosopher)\ **Post date:** [September 9, 2009, 10:29pm UTC](https://boards.straightdope.com/t/relative-risks-of-aids/508860/31 "2009-09-09T22:29:46Z")
> [@Kimmy\_Gibbler](#): > > Per [_Wikipedia:The Free Encyclopedia_, “AIDS”](http://en.wikipedia.org/wiki/AIDS) > _ **Estimated per act risk for acquisition of HIV by exposure route** _ > > **Exposure Route — Estimated infections per 10,000 exposures to an infected source** > Blood Transfusion — 9,000 > Childbirth — 2,500 > Needle-sharing injection drug use — 67 > Percutaneous needle stick — 30 > Receptive anal intercourse\* — 50 > Insertive anal intercourse\* — 6.5 > Receptive penile-vaginal intercourse\* — 10 > Insertive penile-vaginal intercourse\* — 5 > Receptive oral intercourse\*§ — 1 > Insertive oral intercourse\*§ — 0.5 > > - assuming no condom use > § source refers to oral intercourse performed on a man Is it really all that low? Even if you get HIV+ blood transfused into your blood, 10% of the time you won’t get HIV - how is that possible? You could get stuck with an HIV+ needle 10,000 times and only catch HIV on 30 occasions? The figures for sexual intercourse surprise me as well, even though I knew transmission rates were lower than we tend to realize. ---
**Author:** ![susan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/susan/32/17537_2.png) [@susan](https://boards.straightdope.com/u/susan)\ **Post date:** [September 10, 2009, 12:02am UTC](https://boards.straightdope.com/t/relative-risks-of-aids/508860/32 "2009-09-10T00:02:43Z")
Note that with adequate precautions such as are available in the US, the rate of mother-to-child transmission can be knocked down to almost nothing. ---
**Author:** ![Aji\_de\_Gallina](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aji_de_gallina/32/260_2.png) [@Aji\_de\_Gallina](https://boards.straightdope.com/u/Aji_de_Gallina)\ **Post date:** [September 10, 2009, 4:35am UTC](https://boards.straightdope.com/t/relative-risks-of-aids/508860/33 "2009-09-10T04:35:08Z")
> [@panache45](#): > > And the Pope didn’t help the situation, telling them to stop using condoms. Yeah, lots of Catholics who have extra- or pre- marital sex are thinking “I’ll fuck her but no condom, no , no, no…because THAT would be wrong” ---
**Author:** ![GilaB](https://avatars.discourse-cdn.com/v4/letter/g/8e7dd6/32.png) [@GilaB](https://boards.straightdope.com/u/GilaB)\ **Post date:** [September 10, 2009, 6:20pm UTC](https://boards.straightdope.com/t/relative-risks-of-aids/508860/34 "2009-09-10T18:20:59Z")
> [@panache45](#): > > And the Pope didn’t help the situation, telling them to stop using condoms. > [@Aji\_de\_Gallina](#): > > Yeah, lots of Catholics who have extra- or pre- marital sex are thinking “I’ll fuck her but no condom, no , no, no…because THAT would be wrong” It’s more complicated than that. The Catholic Church provides much of the (limited) medical care in certain areas of Africa, so if the Pope says not to use condoms, the Church-run clinics don’t stock them, or give them out to patients. This means that people in the area (Catholic or not) have much less condom access and are thus significantly less likely to use them. ---
**Author:** ![lazybratsche](https://avatars.discourse-cdn.com/v4/letter/l/ba8739/32.png) [@lazybratsche](https://boards.straightdope.com/u/lazybratsche)\ **Post date:** [September 10, 2009, 7:25pm UTC](https://boards.straightdope.com/t/relative-risks-of-aids/508860/35 "2009-09-10T19:25:22Z")
> [@The\_Great\_Philosopher](#): > > Is it really all that low? Even if you get HIV+ blood transfused into your blood, 10% of the time you won’t get HIV - how is that possible? You could get stuck with an HIV+ needle 10,000 times and only catch HIV on 30 occasions? The figures for sexual intercourse surprise me as well, even though I knew transmission rates were lower than we tend to realize. I don’t know where the numbers come from, but I’d guess there is pretty good data for percutaneous needle sticks. In a hospital setting, accidental needle sticks happen at a non-trivial rate, and in most (if not all cases) are followed up with testing and reporting. That way you can get accurate statistics: hundreds if not thousands of cases of health workers exposed to HIV via needle stick, and x resulting cases of HIV. I’m curious where the rest of the estimates come from. I’ll chase down the sources this afternoon if I have some free time… Still, even if the numbers are pretty ballpark, I have confidence in the ability of epidemiologists to come up with good order-of-magnitude estimates. ETA: [Here’s a CDC source](http://www.cdc.gov/niosh/docs/2000-108/) on accidental needle sticks, showing where one source of numbers is. They specifically mention 21 cases of HIV developing from 6498 exposures, which averages to the figure given on wikipedia. ---
**Author:** ![Nametag](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/nametag/32/406_2.png) [@Nametag](https://boards.straightdope.com/u/Nametag)\ **Post date:** [September 15, 2009, 9:44pm UTC](https://boards.straightdope.com/t/relative-risks-of-aids/508860/36 "2009-09-15T21:44:30Z")
> [@Nicolas\_Bourbaki](#): > > I don’t know nada about smack, and it’s been a long time since I saw _Trainspotting_, so mea culpa. But seriously, [what’s the motivation behind it](http://i530.photobucket.com/albums/dd345/mordant_carnival/why_would_you_do_that.jpg), and not just, yaknow, skip that step if you’re doing something as retarded as sharing needles? It’s to test whether the needle is in the vein; if blood comes back, it’s in. There may be other reasons based on ignorance, culture, or personal preference. [Previous page](https://boards.straightdope.com/t/relative-risks-of-aids/508860.md?page=1)