Q and A


Why did my partner test positive when I tested negative?

My partner and I have been together for six years. He tested positive three years ago.

Automatically assuming I would be infected already we continued to have unsafe sex. I never went for a test until three years later in 2012.

He was beginning his treatment and wanted me to do the same, but when I went to my local clinic I tested HIV negative.

Can I trust these results or should I worry about testing HIV positive in near future? I’m so confused!


It is very common for someone to still be negative even if they have not been using condoms with someone who is HIV positive. HIV is quite a difficult virus to catch, so your negative result is also related to good luck.

As your partner has just started treatment, the risk of transmission will already be much lower. Then, once his viral load becomes undetectable the risk is effectively zero..

The PARTNER study showed that treatment dramatically reduces the chance of further sexual transmission.  For example, after 58,000 times that an HIV positive person had sex without a condom with an HIV negative partner, there were ZERO transmissions. This needed viral load to be undetectable on treatment.

This and other studies led to the U=U campaign (undetectable = untransmittable).

This guide to HIV testing and risks of sexual transmission includes more info on transmission risk. Also, the answer to Question 9 on our most asked questions page:
Can we stop using condoms if viral load is undetectable on treatment?

If your partner in not on treatment or if he still has detectable viral load, then using condoms will make sure you stay negative. Another option is to talk to your doctor about PtRP, which is where you can take a pill that will protect you against HIV. The UK guide to PrEP has more info.

Note: This answer was updated in January 2018 and July 2016 from a question first posted online in July 2012.


  1. Lisa Thorley

    Hi Andrew,

    Please see the above post and Q1here:


  2. Andrew

    Hi. My wife and I just came back from the health department. We had a rapid HIV test done. It was the mouth swab one. My result came back positive. But her’s came back negative. After mines came back positive, the official highly recommended I’d do a blood test. I will get back my blood results in 1-2 weeks he says. But why did my rapid test comeback positive and my wife’s negative? This gives me hope that my positive could potentially be a false-positive, but time will determine that. I am truly scared and frightened.

  3. Lisa Thorley

    Hi James,

    If you’re positive, you need to be on meds. This will help you control your HIV. For more info, please see here:


    Being on meds is also very important stopping HIV transmission.

    If you’ve been having sex with your wife without using a condom and since you’ve been positive there is a risk that she too will be positive. Therefore, its very important that she has a test. This is urgent due to her pregnancy.

    This may be a hard thing to do, however if she is positive she will need to be on meds. If she isn’t she risks infecting your baby.

  4. James

    I tested negative back in 2015. However, I tested positive on 18th May, 2017. My partner is pregnant and I have not told her cos of fear of how she might feel. I haven’t started any treatment cos I don’t know what to do. Should I tell my wife?

  5. Lisa Thorley

    Hi Yanda,

    Please see Q’s 1 and 9 here:


  6. yanda

    Hi last week i had sex with an HIV positive person, we were using protection when he penetrated me from behind he took the condom off. But i saw this in a like 5 seconds and pushed hin away. What are the chances of me being infected?

  7. Lisa Thorley

    Hi Maurice,

    Please see Q’s 1, 5 and 8 here:


  8. Maurice

    I after 1 year of unprotected sex, we found out my partner was reactive. I had my 4th gen on the 7th week and 3rd gen on the 3rd month with both negative result. Is it conclusive already or do you have any suggestion regarding any test that can help me free from my worries? Thank you.

  9. Lisa Thorley

    Hi Steve,

    If you’ve had both a negative and positive result, this needs to be confirmed. If it comes back that you are positive, please contact us.