TY - JOUR

T1 - Risk of HIV transmission through condomless sex in serodifferent gay couples with the HIV-positive partner taking suppressive antiretroviral therapy (PARTNER)

T2 - final results of a multicentre, prospective, observational study

AU - Rodger, Alison J

AU - Cambiano, Valentina

AU - Bruun, Tina

AU - Vernazza, Pietro

AU - Collins, Simon

AU - Degen, Olaf

AU - Corbelli, Giulio Maria

AU - Estrada, Vicente

AU - Geretti, Anna Maria

AU - Beloukas, Apostolos

AU - Raben, Dorthe

AU - Coll, Pep

AU - Antinori, Andrea

AU - Nwokolo, Nneka

AU - Rieger, Armin

AU - Prins, Jan M

AU - Blaxhult, Anders

AU - Weber, Rainer

AU - Van Eeden, Arne

AU - Brockmeyer, Norbert H

AU - Clarke, Amanda

AU - Del Romero Guerrero, Jorge

AU - Raffi, Francois

AU - Bogner, Johannes R

AU - Wandeler, Gilles

AU - Gerstoft, Jan

AU - Gutiérrez, Felix

AU - Brinkman, Kees

AU - Kitchen, Maria

AU - Ostergaard, Lars

AU - Leon, Agathe

AU - Ristola, Matti

AU - Jessen, Heiko

AU - Stellbrink, Hans-Jürgen

AU - Phillips, Andrew N

AU - Lundgren, Jens

AU - PARTNER Study Group

N1 - Copyright © 2019 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 license. Published by Elsevier Ltd.. All rights reserved.

PY - 2019/6/15

Y1 - 2019/6/15

N2 - BACKGROUND: The level of evidence for HIV transmission risk through condomless sex in serodifferent gay couples with the HIV-positive partner taking virally suppressive antiretroviral therapy (ART) is limited compared with the evidence available for transmission risk in heterosexual couples. The aim of the second phase of the PARTNER study (PARTNER2) was to provide precise estimates of transmission risk in gay serodifferent partnerships.METHODS: The PARTNER study was a prospective observational study done at 75 sites in 14 European countries. The first phase of the study (PARTNER1; Sept 15, 2010, to May 31, 2014) recruited and followed up both heterosexual and gay serodifferent couples (HIV-positive partner taking suppressive ART) who reported condomless sex, whereas the PARTNER2 extension (to April 30, 2018) recruited and followed up gay couples only. At study visits, data collection included sexual behaviour questionnaires, HIV testing (HIV-negative partner), and HIV-1 viral load testing (HIV-positive partner). If a seroconversion occurred in the HIV-negative partner, anonymised phylogenetic analysis was done to compare HIV-1 pol and env sequences in both partners to identify linked transmissions. Couple-years of follow-up were eligible for inclusion if condomless sex was reported, use of pre-exposure prophylaxis or post-exposure prophylaxis was not reported by the HIV-negative partner, and the HIV-positive partner was virally suppressed (plasma HIV-1 RNA <200 copies per mL) at the most recent visit (within the past year). Incidence rate of HIV transmission was calculated as the number of phylogenetically linked HIV infections that occurred during eligible couple-years of follow-up divided by eligible couple-years of follow-up. Two-sided 95% CIs for the incidence rate of transmission were calculated using exact Poisson methods.FINDINGS: Between Sept 15, 2010, and July 31, 2017, 972 gay couples were enrolled, of which 782 provided 1593 eligible couple-years of follow-up with a median follow-up of 2·0 years (IQR 1·1-3·5). At baseline, median age for HIV-positive partners was 40 years (IQR 33-46) and couples reported condomless sex for a median of 1·0 years (IQR 0·4-2·9). During eligible couple-years of follow-up, couples reported condomless anal sex a total of 76 088 times. 288 (37%) of 777 HIV-negative men reported condomless sex with other partners. 15 new HIV infections occurred during eligible couple-years of follow-up, but none were phylogenetically linked within-couple transmissions, resulting in an HIV transmission rate of zero (upper 95% CI 0·23 per 100 couple-years of follow-up).INTERPRETATION: Our results provide a similar level of evidence on viral suppression and HIV transmission risk for gay men to that previously generated for heterosexual couples and suggest that the risk of HIV transmission in gay couples through condomless sex when HIV viral load is suppressed is effectively zero. Our findings support the message of the U=U (undetectable equals untransmittable) campaign, and the benefits of early testing and treatment for HIV.FUNDING: National Institute for Health Research.

AB - BACKGROUND: The level of evidence for HIV transmission risk through condomless sex in serodifferent gay couples with the HIV-positive partner taking virally suppressive antiretroviral therapy (ART) is limited compared with the evidence available for transmission risk in heterosexual couples. The aim of the second phase of the PARTNER study (PARTNER2) was to provide precise estimates of transmission risk in gay serodifferent partnerships.METHODS: The PARTNER study was a prospective observational study done at 75 sites in 14 European countries. The first phase of the study (PARTNER1; Sept 15, 2010, to May 31, 2014) recruited and followed up both heterosexual and gay serodifferent couples (HIV-positive partner taking suppressive ART) who reported condomless sex, whereas the PARTNER2 extension (to April 30, 2018) recruited and followed up gay couples only. At study visits, data collection included sexual behaviour questionnaires, HIV testing (HIV-negative partner), and HIV-1 viral load testing (HIV-positive partner). If a seroconversion occurred in the HIV-negative partner, anonymised phylogenetic analysis was done to compare HIV-1 pol and env sequences in both partners to identify linked transmissions. Couple-years of follow-up were eligible for inclusion if condomless sex was reported, use of pre-exposure prophylaxis or post-exposure prophylaxis was not reported by the HIV-negative partner, and the HIV-positive partner was virally suppressed (plasma HIV-1 RNA <200 copies per mL) at the most recent visit (within the past year). Incidence rate of HIV transmission was calculated as the number of phylogenetically linked HIV infections that occurred during eligible couple-years of follow-up divided by eligible couple-years of follow-up. Two-sided 95% CIs for the incidence rate of transmission were calculated using exact Poisson methods.FINDINGS: Between Sept 15, 2010, and July 31, 2017, 972 gay couples were enrolled, of which 782 provided 1593 eligible couple-years of follow-up with a median follow-up of 2·0 years (IQR 1·1-3·5). At baseline, median age for HIV-positive partners was 40 years (IQR 33-46) and couples reported condomless sex for a median of 1·0 years (IQR 0·4-2·9). During eligible couple-years of follow-up, couples reported condomless anal sex a total of 76 088 times. 288 (37%) of 777 HIV-negative men reported condomless sex with other partners. 15 new HIV infections occurred during eligible couple-years of follow-up, but none were phylogenetically linked within-couple transmissions, resulting in an HIV transmission rate of zero (upper 95% CI 0·23 per 100 couple-years of follow-up).INTERPRETATION: Our results provide a similar level of evidence on viral suppression and HIV transmission risk for gay men to that previously generated for heterosexual couples and suggest that the risk of HIV transmission in gay couples through condomless sex when HIV viral load is suppressed is effectively zero. Our findings support the message of the U=U (undetectable equals untransmittable) campaign, and the benefits of early testing and treatment for HIV.FUNDING: National Institute for Health Research.

KW - Adult

KW - Anti-HIV Agents/therapeutic use

KW - Antiretroviral Therapy, Highly Active

KW - Condoms

KW - HIV Seropositivity/transmission

KW - Homosexuality, Male

KW - Humans

KW - Male

KW - Middle Aged

KW - Prospective Studies

KW - Sexual Partners

KW - Unsafe Sex

KW - Viral Load

U2 - 10.1016/S0140-6736(19)30418-0

DO - 10.1016/S0140-6736(19)30418-0

M3 - Journal article

C2 - 31056293

VL - 393

SP - 2428

EP - 2438

JO - The Lancet Oncology

JF - The Lancet Oncology

SN - 1470-2045

IS - 10189

ER -