Question

Chances of infecting partner if I have an undetectable viral load?

5 February 2018. Related: All topics, CD4 and viral load, HIV transmission, Sero different couples.

I have been positive for three years now and started treatment two months ago. If my viral load is undetectable can I still infect someone? Are the chances of infecting my partner still the same if we had unprotected sex?

Answer

Answer: Simon Collins

Thank you for your questions.

In 2018, the answer to your question is a clear “no”.

Having an undetectable viral load makes HIV untransmittable. The evidence for this is at this link:
https://i-base.info/htb/32308

This was already believed by some experts in 2008 (when this question was first answered). The statement on behalf of the Swiss Federal Commission for HIV and AIDS authored by four of Switzerland’s foremost HIV experts said that an HIV infected person on ART with an undetectable viral load cannot transmit HIV through sexual contact. This information was published in the Bulletin of Swiss medicine in January 2008 was largely based on data from heterosexual sex.

See this factsheet on the Swiss Statement.

Note: This answer was updated in February 2018 from a question first posted online in February 2008.

45 comments

Simon Collins • 13 October 2016

Hi Henry – yes – the main goal of treatment is to get viral load to undetectable. This easy guide has lots of related info about starting treatment:
http://i-base.info/guides/starting
Henry • 13 October 2016

Hi
I just found out that am hiv+ if I start treatment can the viral load be reduced?
Simon Collins • 11 October 2016

Hi Precious, it is safe for you to conceive naturally. Treatment dramatically reduces ay risk to your boyfriend to close to zero. Many countries now routinely recommended this as the best way for to have a baby. This link has more information.
http://i-base.info/guides/pregnancy/what-to-do-when-one-partner-is-hiv-positive-and-the-other-is-hiv-negative
precious • 11 October 2016

hi
I am HIV positive,been on treatment for a year now.my CD4 count is 1300 and viral load is 0.66,my boyfriend has been talking about how much he wants a kid…wht is the possibility of him getting infected?
Simon Collins • 23 July 2016

Hi Lamont. It would be better to wait until you have been undetectable for a couple of months before you decide whether or not to stop using condoms. This is because viral load in semen (cum) take a little longer to become undetectable. After this, then the PARTNER study reported that no transmissions occurred after about 900 couples had sex 58,000 time without condoms. See:
http://i-base.info/qa-on-the-partner-study
lamont • 23 July 2016

Hi me and my girlfriend wanna know can we have unprotected sex. I went to the Dr this week and he told me I’m undetectable an I have to know can me an my girlfriend have unprotected sex since I’m undetectable now.
Robin Jakob • 18 April 2016

Thank you for the feedback!
namungoma • 18 April 2016

Wonderful answers. I’m now relaxed because I know the facts, thank you team.
Robin Jakob • 28 January 2015

Hi,

It is great that you are thinking about getting pregnant. Many couples like yours, with one positive and one negative partner, safely conceive. This is now usually done like your doctor described. Because your viral load is so low the risk of transmission to your partner is extremely low.

You can find more information here:
http://i-base.info/guides/pregnancy
felicity • 28 January 2015

Hi I am HIV positive. My husband is negative. Last week I went to my doctor for a CD4 count check up it’s 758. My viral load is 20. My doctor told me that since we want to have kids we can try without protection during my ovulation period. He told me there are no chances for him to be infected. I just want to be sure how true is that?