Partner 2 study extended for gay couples
Simon Collins, HIV i-Base
The second phase of the PARTNER Study aims to estimate the risk of HIV transmission in gay sero-discordant couples. 
To enrol, the HIV positive partner needs to be on ART with an undectectable viral load and the couple need to be sexually active and not always using condoms.
A total of 950 gay male (MSM) couples are needed for PARTNER 2 and currently 470 MSM couples are already participating in the first phase of the PARTNER study.
MSM couples already participating in PARTNER 1 will be encouraged to continue follow-up in PARTNER 2 until 2017.
Interim results presented at CROI 2014 reported no linked transmissions after 894 eligible couple-years of follow up and more than 44,500 exposures (half of which involved anal sex without a condom). 
The additional follow-up will provide similar confidence levels for the residual risk of HIV transmission for gay men compared to heterosexual couples.
UK sites for PARTNER 2
- Chelsea and Westminster, London
- Mortimer Market Centre, London
- Royal Free Hospital, London
- St. Thomas’s London
- Western General Hospital, Edinburgh
- Royal Sussex County Hospital, Brighton
- Southmead Hospital, Bristol
New sites are still being sought for this second phase. For further information, please contact the study coordinator Tina Bruun:
- Partners of people on ART: a New Evaluation of the Risks (PARTNER), 2014-2017.
- Rodger A et al. HIV transmission risk through condomless sex if HIV+ partner on suppressive ART: PARTNER Study. 21st CROI, 3-6 March 2014, Boston. Oral late breaker abstract 153LB.