HIV incidence appears constant in men who have sex with men despite widespread use of effective antiretroviral therapy

To estimate the trend in HIV incidence between 1995 and 2001 in men who have sex with men (MSM) attending sexually transmitted infection (STI) clinics in the UK. The Serological Testing Algorithm for Recent HIV Seroconversion (STARHS) was applied to serum specimens from MSM attending 15 STI clinics collaborating in an HIV unlinked anonymous prevalence serosurvey. STARHS was performed on anti-HIV-1 positive specimens and HIV incidence rates determined. Specimens from MSM with previously diagnosed HIV or an AIDS defining condition were excluded. National data on uptake of antiretroviral therapy (ART), AIDS mortality and diagnoses of gonorrhoea in MSM were used to aid interpretation of the HIV incidence findings. Of 43,100 specimens collected from MSM 3565 were anti-HIV-1 positive. Of these, 1645 were eligible and available for STARHS testing, of which 317 were deemed to come from recently acquired infections. The overall estimated annual incidence ranged from 1.5% (1999) to 3.3% (1996). In 2001 it was 2.45%, with a 3.1% incidence in London and 1.0% elsewhere. No significant trends in HIV incidence were found. Despite the widespread use of ART there was no significant decline in HIV incidence. Individuals whose HIV infection has been diagnosed should be less infectious. However, over 20% of infections in MSM remain undiagnosed, many with acute STI, and this pool of unmanaged HIV infection may be an important driver of the ongoing epidemic. Initiatives to diagnose and treat a greater proportion of HIV infections may be the key to reducing HIV incidence in MSM.