Q and A

Question

Can I have sex with someone who is positive and not catch HIV?

16 January 2018. Related: All topics, HIV transmission.

Answer

Answer: Simon Collins

Yes, there are lots of ways to make sure HIV is not transmitted during sex.

  1. One of the easiest and most effective ways is just for the HIV positive partner to be on treatment. An undetectable viral load makes HIV untransmittable. (See: The evidence for U=U).
  2. Another relatively recent option is for the negative partner to use PrEP. This is an oral drug that when taken as prescribed is highly effective. (See: UK guide to PrEP).
  3. You can use condoms which are an effective barrier against HIV (and other STIs). Condoms need to be used carefully, preferably with plenty of lube. (See: How to use a condom (male and female).

HIV is a much less infectious virus than many other sexually transmitted infections (STI’s).

Even without a condom, the risk from a single exposure is less than, for example, 1 in 300. The actual risk becoming infected varies depending on many factors. These include the type of exposure, whether the other person is HIV positive, how high or low their viral load is, the duration and roughness of the sex etc.

If the partner is HIV positive, then viral load is the most important factor. The PARTNER study reported zero HIV transmissions after 900 couples had sex more than 58,000 times WITHOUT condoms. In this study undetectable viral load was defined as being less than 200 copies/mL.
https://i-base.info/qa-on-the-partner-study

Risk factors for penetrative sex without a condom with someone who has a very high viral load could be as high as 1 in 10 (10% risk). But the risk is effectively zero with someone who is taking treatment and who has an undetectable viral load.

This question was updated in January 2018 and November 2016 from an original answer posted in June 2007. i-Base no longer answers individual questions about HIV transmission and risk. (See: Question 1 at this link).

209 comments

  1. Azjz •

    Iam aziz khan 35 years old male

    Is hiv possible from a infectd lady from just only one meeting or once sex with her

    Waiting for ur kindly replay

  2. Simon Collins •

    Hi Peter – please see questions 1 and 5 at this link:
    http://i-base.info/qa/what-are-the-most-asked-questions

  3. peter •

    hello,i have been dating a girl since April and having sex with her almost daily.I did the test twice in differences of one month and it was negative,she tested once and she was positive.Is this possible that she has and i don’t have???

  4. Simon Collins •

    Hi Kings – please see questions 1 at this link:
    http://i-base.info/qa/what-are-the-most-asked-questions

  5. kings •

    I have been feeling all the symptoms of a HIV positive person. Like fatigue, diarrhea,flu,soar throat,low temp,headache, am scared and is it possible to feel all this things and still have a HIV free life. I have not done the test. But I did it early feb this year. And it say HIV negative. But now we where are in oct. and am feeling all the symptoms. #crying. #amScared

  6. Simon Collins •

    Hi Vinod, please see Question 1 at this link:
    http://i-base.info/qa/what-are-the-most-asked-questions

  7. Vinod •

    I had paid for sex with a woman and I was drunked during sex. I don’t no weather she has HIV after having sex I noticed that there was no condom. i am fearing about this situation.

  8. Simon Collins •

    Hi Java, HIV is very difficult to catch from one exposure – the risk might be 1 in 500 chance for example – so there are 499 in 500 chances that HIV is not transmission. If the person is on treatment – and most people are – then the risk is close to zero.

  9. Java •

    Hi i slept with a girl who is HIV positive 2days ago but sex was not rough is anything i can do to prevent before it
    replicate?

  10. Simon Collins •

    Hi Issac, as you can see from this original answer and the many comments afterwards, your situation is common. HIV is difficult to catch and you have just been very lucky. How is your partner coping as your support will be very important. For your own health, it is good to start using condoms now, but after your wife is on treatment the risk to you becomes so low that you can stop using condoms if you want to. See the APRTNER study results for info in this.
    http://i-base.info/qa-on-the-partner-study/
    Info about testing and transmission is linked to this answer:
    http://i-base.info/qa/11844