Is use of antiretroviral therapy among homosexual men associated with increased risk of transmission of HIV infection?

Methods: A cross sectional study of 420 HIV positive homosexualmen attending a London outpatient clinic. Individual data werecollected from computer assisted self interview, STI screening,and clinical and laboratory databases.

Results: Among all men, sexual behaviour associated with a highrisk of HIV transmission was commonly reported. The most frequentlyreported type of partnership was casual partners only, and 22%reported unprotected anal intercourse with one or more new partnersin the past month. Analysis of crude data showed that men onHAART had fewer sexual partners (median 9 versus 20, p=0.28),less unprotected anal intercourse (for example, 36% versus 27%had insertive unprotected anal intercourse with a new partnerin the past year, p=0.03) and fewer acute sexually transmittedinfections (33% versus 19%, p=0.004 in the past 12 months) thanmen not on HAART. Self assessed health status was similar betweenthe two groups: 72% on HAART and 75% not on HAART rated theirhealth as very or fairly good, (p=0.55). In multivariate analysis,differences in sexual risk behaviour between men on HAART andmen not on HAART were attenuated by adjustment for age, timesince HIV infection. CD4 count and self assessed health status.

Conclusion: HIV positive homosexual men attending a London outpatientclinic commonly reported sexual behaviour with a high risk ofHIV transmission. However, behavioural and clinical risk factorsfor HIV transmission were consistently lower in men on HAARTthan men not on HAART. Although use of HAART by homosexual menwith generally good health is not associated with higher riskbehaviours, effective risk reduction interventions targetingknown HIV positive homosexual men are still urgently needed.