Objective To examine changes in HIV testing and undiagnosed infection among men who have sex with men in Scotland between 2005 and 2008.

Methods Self-completed questionnaires and Orasure oral fluid collection kits were distributed to men visiting the commercial gay scene in Glasgow and Edinburgh.

Results Questionnaires and oral fluid specimens were provided by 1350 men (51.6% response rate) in 2005 and 1277 (59.7% response rate) in 2008. 2572 men were eligible for inclusion in the analyses. Recent HIV testing increased from 33.2% in 2005 to 48.3% in 2008 (p<0.001). HIV prevalence was comparable in 2005 and 2008 (4.4% and 4.6%, respectively). Among HIV-positive men, there was a reduction in undiagnosed infection between 2005 and 2008 from 41.7% to 26.3% (p=0.08). Undiagnosed HIV did not differ between men who were and were not tested in the past year. In 2008, only four (26.7%) HIV-positive men tested in the past 6 months were undiagnosed, compared with 11 (42.3%) HIV-positive men who had not tested (p=0.03).

Conclusion There was a substantial increase in recent HIV testing between 2005 and 2008. Although there was a concurrent (non-significant) reduction in undiagnosed HIV, there was no difference in undiagnosed infection between men who had and had not tested recently. However, lower proportions of undiagnosed infection among the most recent HIV-positive testers suggest frequent testing could play a role in reducing undiagnosed HIV and should remain central to HIV prevention efforts.