Question
if you have sex with someone who has HIV are you guaranteed to catch HIV?
10 January 2018. Related: All topics, HIV transmission.
Answer
No, the opposite is true, HIV is a difficult virus to catch.
The actual risk in any single situation probably vary from zero (no risk) to to less than 1 in 20,000 (0.05% risk per exposure) to 1 in 10 (10% risk per exposure). This will depend on many things, including: the viral load of the HIV positive partner, the type of sex, whether you use a condom, if there are STIs, genetics etc).
The risk is zero if the positive partner is on treatment (ART) with an undetectable viral load. An undetectable viral load makes HIV untransmittable. (See: The evidence for U=U).
Low risks (1 in 5,000) include oral sex generally (not in early infection), or perhaps the risk of a condom breaking.
High risk – perhaps 1 in 100 to 300 – is estimated from vaginal or anal intercourse without using a condom (not accounting for viral load), or for oral sex with someone who has recently been infected.
Highest risk would involve blood to blood contact with someone who has a high viral load.
Although HIV is not an easy virus to catch – it does only takes one exposure for infection to occur in any risk setting other than zero. There is probably zero risk if the positive partner has undetectable viral load, if the negative partner uses PrEP or when condoms are used properly.
Many HIV positive people have sex with HIV negative people, including in long-term relationships, without the negative person catching HIV.
See also the info and links from this page.
This question was updated in January 2018 from an original answer posted in May 2008. i-Base no longer answers individual questions about HIV transmission and risk. (See: Question 1, 5, 6 and 9 at this link).
Comments to this thread are now closed.
You’re not the first person to find this difficult, many people have gone through exactly the same worries.
But look at Simon’s answer to the question ‘How can I tell my partner I’m positive?’. It’s a good guide about where to start and the ways that you can do it.
You can start by finding out what your partner thinks about HIV generally, and not mention yourself then. You can build on this to work out the best thing to do.
Good luck and best wishes,
I’m postive and I dont know how to spit it out to my boyfriend
I’m really sorry to hear this news. It’s understandable that you are devastated and angry.
It’s good that you’ve done the blood tests and are waiting for the result. Have you asked the doctor if your partner was on HIV treatment (ART)? This is one of the factors that can affect your result. Being undetectable on ART can dramatically reduce the risk of transmission.
But there are many factors that increase or reduce the risk of transmission.
The answer to the question above shows how risk depends on many things.
Can you ask the doctor if they provide support while you wait for the result and confirmation?
My partner of 4 years passed a few weeks ago. His Dr managed to contact me and told me he was diagnosed with HIV 5 years ago. How devasted and angry I am now. I’ve just done the blood test and I’m waiting nervously with uncontrolled tears and hopelessly scared to hear a positive result. How dare he, he did not tell me and he never used a condom, I didn’t have any doubts. How selfish, I can’t wait to find out if I am affected.
It’s quite common for one partner to test positive and the other negative. This can be explained by luck and different other risk factors.
It’s important that your boyfriend is on HIV treatment (ART) because, if this keeps HIV to undetectable levels, it can help protect you from HIV.
Using condoms can reduce this risk completely. You can ask the doctor to confirm your HIV negative result 90 days after the last time you were at risk.
I am really scared. I have been dating my boyfriend for 6 months and he never told me that he is HIV positive. 3 days ago I found his pills at his house when I ask him. He cried and told me that he is HIV positive, my fear is that we have been not using a condom since 4 month ago. When we went to the clinic the results became negative and my boyfriend positive.
We no longer answer questions about testing and transmission. This service is for people who are HIV positive and for questions about treatment.
But the only way to find out if you are HIV positive is to get tested.
Most questions about transmission or testing have been answered here:
http://i-base.info/qa/factsheets/hiv-transmission-and-testing
I would to know that how long does it take to know that you are HIV positive is you sleep with an infected person . How do you know that you are infected without testing
Hi Kelebogile, it is great that you have been so careful and that you are worried about your boyfriend. The risk from this one time is very low. Becaseu you have been on treatment for three years, if your viral load is undetectable, then your boyfirend will definitely be okay. Over the last few years we have learnt that having an undetectable viral load makes it very difficult to transmit HIV.
I’m felling so angry with myself because I just did something bad to someone I really care and love. was just going with the flow but now I think it to late my boyfriend is HIV negative and I’m HIV positive. I’m taking my pills its over 3 year now but today we just lost it we slept without a condom. I don’t know what to do I really need to help him please I love him to much.