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. John •

    My wife is HIV positive but I am negative, many time I did my test it came out negative. But I am also O+ in blood and she is B+ , and I don’t take any antiriotroviral drugs. What cause this to happened like this.

  2. Simon Collins •

    Hi Mulenga, if your viral load is undetectable on treatment, the risk to your wife is close to zero. You can try for another probably by conceiving naturally. See this article on the PARTNER study.
    http://i-base.info/qa-on-the-partner-study

  3. Mulenga •

    I am HIV positive and on ART while my wife is negative .
    we have one child is there a way of having another child with out putting my wife at risk.

  4. Simon Collins •

    Hi Tyne, please see:
    http://i-base.info/qa/factsheets/hiv-transmission-and-testing

    PEP doens’t work after 6 days but your risk sound low.

  5. Tyne •

    Hi, I was drunk and have unprotected sex with a lady whom am not even know her status twice that night can I be at risk? I have unprotected sex with a person whom I am suspecting to be HIV positive and it’s 6 day now since we had that unprotected sex, can Pep still or possibility of working on me if am positive.

  6. Kelvin •

    I had sex 2times with a lady I used condom on her..but after a month she told me that was going to pharmacy to get some medication…so I asked her if she is sick and she said yes that she’s hiv positive….so now I don’t know if am into trouble now…please is their any risk to it?

  7. Simon Collins •

    Hi Kevin, first you used a condom so you ar enot at risk. Secondly – and this is becoming very important – if someone is on effective treatment, they become dramatically less infectious. This makes it is very difficult to catch HIV even if you don’t use a condom. Read this link to understand this for yourself.
    http://i-base.info/qa-on-the-partner-study

  8. Simon Collins •

    Hi Tando

    please see this FAQ page on risk and testing.
    http://i-base.info/qa/factsheets/hiv-transmission-and-testing

  9. Tando •

    Good day

    Am not sure if a could be infected or not I had two nights with this HIV and we tested I was negative with one line her turn on a test kit it showed two lines C Nd T I there assume she was infected and she new about it but we’ll appart from that a had two night and during sex I would take out my penile when I sperm and sperm on her chest so my worry of the fluids and did not clean myself after tell what are the risks involved

  10. Simon Collins •

    Hi Grant

    Pls see the answers above and these links.

    Answers to questions on testing are already online at the FAQ page.
    http://i-base.info/qa/factsheets/hiv-transmission-and-testing

    or in this guide:
    http://i-base.info/guides/testing