Chlamydia trachomatis infection and non-gonococcal urethritis in homosexual and heterosexual men in Edinburgh.

In 1998, when ligase chain reaction testing for chlamydial infection was introduced in our clinic in Edinburgh, routine clinic protocol included the testing of all heterosexual, but not homosexual, men for urethral chlamydial infection. We audited all new homosexual and bisexual male attendees with a diagnosis of chlamydial infection or non-gonococcal urethritis (NGU) in 1999, together with heterosexual men with the same diagnoses attending in alternate months of the same year. Urethral Chlamydia trachomatis infection was detected in 14.6% (350/2402) of heterosexual men and 2.4% (11/465) of homosexual men tested. Fifty percent of chlamydial infections were asymptomatic. In this population 44% (84/190) of NGU in heterosexual men is attributable to C. trachomatis as opposed to only 10% (6/59) of that in homosexual men. These rates of chlamydial infection differ from previous reports in Scotland and recent studies from the USA. Our clinic protocol has been revised to include routine testing for chlamydial infection in all men.