In 2006, the US Centers for Disease Control and Prevention recommended expanding HIV testing in healthcare settings1 in order to identify the estimated 25% of HIV-infected persons who are unaware of their status and who may be responsible for up to 50% of HIV transmission.2 These recommendations partly attribute the failure of risk-based testing to issues related to access to care and the inability to target testing if individuals do not admit to potentially stigmatising risk behaviours or are unaware of their risk. However, in this issue of Sexually Transmitted Infections, Brown and colleagues3 (see page 4) present data that suggest that the failure of targeted testing may be partly due to missed opportunities for HIV testing in readily identified high-risk populations.

Studying men who have sex with men (MSM) attending 15 genitourinary medicine (GUM) clinics in the UK between 1999 and 2002, the authors detected anti-HIV antibodies in 737 (6.7%) of 10 935 specimens obtained during visits when blood was obtained for syphilis testing but HIV testing did not occur (fig 1). These results are consistent with other published studies, including an anonymous serosurvey conducted at 28 US sexually transmitted disease (STD) clinics in 1997. In nearly all clinics HIV prevalence was 1.4 to 18 times higher …