Objectives: Undiagnosed infection presents a potential risk for the onward transmission of HIV and denies men early interventions for their health. Little is known about the differences between men who are, and are not, aware of their HIV status in the UK.
Methods: Cross-sectional surveys of men in commercial gay venues in London, Brighton, Manchester, Glasgow, and Edinburgh (2003-2005). Anonymous, self-completion questionnaires, and oral fluid samples (tested for HIV antibodies) were obtained from 3672 men (61% response rate).
Results: Of 3501 men with a confirmed positive or negative oral fluid result, 318 were HIV positive (9.1%). Of these, 131 (41.2%) were undiagnosed; 81.1% of men with undiagnosed HIV had previously tested (92.2% tested negative; the remainder did not know the result); 62.3% still thought that they were negative. Undiagnosed and diagnosed men reported greater sexual risk and sexually transmitted infections than HIV-negative men. Compared with HIV-negative men, the adjusted odds ratio of unprotected anal intercourse with two or more partners was higher among undiagnosed men (odds ratio 2.21, 95% confidence interval 1.17-4.20), but highest among diagnosed men (odds ratio 6.80, 95% confidence interval 4.39-10.52).
Conclusion: A high proportion of the HIV-positive men were undiagnosed and not receiving benefits of clinical care, but sexual risk and sexually transmitted infections were highest among men who were aware of their HIV-positive status. Clinics should proactively offer testing to reduce undiagnosed HIV, target repeat testing at high-risk men who have previously tested negative, and initiate evidence-based behavioural interventions to reduce sexual risk among men living with diagnosed HIV as well as those testing negative.