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Preventing an HIV infection

Visit us (http://www.khanacademy.org/science/healthcare-and-medicine) for health and medicine content or (http://www.khanacademy.org/test-prep/mcat) for MCAT related content. These videos do not provide medical advice and are for informational purposes only. The videos are not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of a qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read or seen in any Khan Academy video. Created by Vishal Punwani.

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Video transcript

- So let's talk about the ways to minimize your risk of getting an HIV infection. And, you know, probably the best way to do this is to identify the high risk situations and talk about steps we can take to protect ourselves from infection in these high risk situations. And actually before I get into that let me just say that there's no vaccine for HIV. So it really comes down to just kind of modifying certain behaviors to reduce our risk of becoming infected. So we can start with the most risky sort of situation. Which is sexual activity right? So sexual intercourse. So vaginal sex. Between a man and a woman. Or anal sex between either man and woman or man and man. Or oral sex between mouth and either penis, vagina or anus. So if either sexual partner is infected then all of these activities pose a risk right? Of transmission of HIV from the infected to the uninfected partner. So strategies to reduce or prevent HIV transmission in these scenarios. Well, you could totally avoid all of these activities right? Abstinence from sex. But whether or not that's something you're willing to do is really up to you but abstinence is really the only way you can be sure that you won't get an infection. So, and actually let's make a nice little list up here. So, ways to reduce or prevent HIV infection. So, abstinence. But other options to reduce the risk of transmission are things like using condoms. In any of these sexual acts right? Vaginal, anal, or oral sex. And also things like having less risky sex. Because you know it turns out that anal sex for a variety of reasons that we've touched on before is by far the highest risk sexual activity for transmission of HIV between either partner. So, being extra careful in making sure that condoms are used in situations like this in particular is extra important in reducing the risk of HIV transmission. And oral sex is actually the less likely form of sex to facilitate HIV transmission. But again in all three of these activities barrier contraception like condoms can significantly reduce the risk of HIV transmission. Provided that they're properly used right? And that's because they are literally a physical barrier right? Like bullet proof glass. That is really effective at preventing any virus from getting across the condom. >From one partner to the other. And I guess another strategy in this sort of sexual domain is to reduce the number of sexual partners that you have. And this is for two reasons. So, one is that the more sexual partners that you have the higher the likelihood is right? I mean, even if it's still a small likelihood. There's still a higher risk that one of your sexual partners has been exposed to HIV. Remember often there's no outward symptoms of an HIV infection. So, limiting your number of partners or just having one uninfected partner that you're in a monogamous relationship with that'll reduce your risk of becoming infected. And the other reason why limiting your number of sexual partners is a good idea in this sense is because well, the fewer the number of sexual partners, the less likely you are to be exposed to any other STI. Any non-HIV sexually transmitted infection. You know, things like chlamydia, gonorrhea, syphilis, herpes. And this is important because a lot of STIs manifest as sores or otherwise sort of broken skin in the genital area. And as we know, broken skin and you know maybe blood in that genital area it makes it a lot easier for HIV to cross from one person to another right? Through that broken skin. So I guess we can add that to our list right? Avoid STIs and treating them if we do have them. And actually I touched on this a bit earlier but let's officially put it on our list, getting ourselves tested. So we know our HIV status right? Positive or negative. And knowing our partner's status as well. Whether they're positive or negative. Now, we can sort of leave this sexual domain there. And we have move on to other ways to prevent HIV transmission. So, we know that sharing needles in IV drug use, intravenous drug use like say sharing heroin injection needles, that activity in particular poses a really high risk of transmitting HIV from one user to the next. Because I mean if you think about it, the person's blood right, one person's blood is going directly from the tip of the used needle straight into the next person's bloodstream right? And then that tip right, that bit of blood, might have some HIV in it. So I think the best way to prevent HIV transmission here is to just absolutely refrain from using IV drugs right? Don't inject drugs. But if you do, then you should only use sterile equipment. Like brand new needles, i.e. you literally opened the packaging yourself. And then don't ever share your equipment with anyone else. That'll cut down on your risk of becoming HIV infected through IV drug use. Okay so those are two of our higher risk activity groups right? Sexual activities and drug use. But now we're gonna change gears a little bit here. So the other higher risk ways to transmit HIV actually have to do with pregnancy and breastfeeding. Because during pregnancy and labor and then the subsequent breastfeeding there's a chance right, and sometimes actually quite a significant chance for an HIV infected mom to pass the HIV on to her little baby. So ways to prevent or at least drastically reduce the risk of transmission of HIV in these scenarios is to take antiretroviral drugs or ARVs. And ARVs work by reducing the amount of virus right, the viral load, in your body. Both in your blood and in your secretion. So things like your breastmilk or your genital or your sexual fluids. So simply by taking your ARVs properly you end up with a way lower risk of passing on any HIV to your kiddos right? And you know this method of preventing transmission this'll be effective in every situation we've talked about so far right? So, any sexual activities, any IV drug use, just lowering the amount of HIV in your body using ARVs, that will directly reduce the risk of transmission to another person. So the last thing I'll say is that there's medications called pre-exposure prophylaxis or PREP, and post exposure prophylaxis or PEP. And these medications can reduce your risk of becoming HIV infected before or after any high-risk situations. So, let's just expand on that a little bit. So, pre-exposure prophylaxis, that's a set of medications that are given to people who have a higher than average risk of contracting HIV. So, for example, you know, HIV-negative people who are in relationships with HIV-positive people. So, in addition to condom usage, these medications aren't really supposed to be used on their own, so in addition to condom usage, the person can get pre-exposure prophylaxis drugs. Which are basically just ARV's that have a good chance of stopping any HIV that gets inside the HIV-negative person's body from actually succeeding in causing an infection in the uninfected person. And post exposure prophylaxis, again are ARV's, that are to be given pretty quickly after an HIV-negative person has just been exposed to HIV. So maybe it's a healthcare worker who was accidentally exposed to HIV through say a needle stick injury. Or maybe someone has had unprotected sex with an HIV-positive person. So these two type of drugs are just ARVs that have a good chance of stopping any HIV that gets inside an uninfected person's body from causing an infection. And these PEPs work best if they're given within an hour of exposure, but they'll still work up to three days after an exposure.