What’s the risk of HIV transmission when viral load is less than 50?

11 July 2011. Related: News.

This is a great question and the answer would be very important. But currently there is worryingly very little evidence to quantify the risk.

A study called PARTNER is looking for sero-different couples (where one partner is HIV-negative and the other is HIV-positive).

Any couples that already sometimes have unprotected sex, can help answer the question within two years. Most of the information reporting low transmission rates when the HIV-positive partner is on treatment come from heterosexual studies. The PARTNER study is also enrolling gay men.

Condoms are still being recommended during the study as this provides they provide the greatest protection.

But the reality for many people is that sometimes they do not use condoms. This study is looking for partners who already are happy having this level or risk.

The study is being run in 14 European countries including the UK.

For information on UK sites see this link to information on the i-Base website, or the PARTNER website.

If you are in the UK can also email Dr Alison Rodger, the lead researcher here.