Epidemiology of infection by serotypes D to K of chlamydia trachomatis.

Non-specific urethritis (NSU) is a sexually transmitted disease; 50% of cases are due to Chlamydia trachomatis, so that this is the commonest sexually transmitted infection in the developed world. Chlamydial infection is now readily diagnosable and the evidence increasingly suggests that it is underdiagnosed. Chlamydial conjunctivitis (in the newborn baby or the adult) in the developed world is a complication of sexually transmitted genital infection by C trachomatis and it indicates a large reservoir of such infections. Because of the association of sexually transmitted diseases, systemic treatment for such chlamydial conjunctivitis should not be given until full genital and serological investigators have been carried out. Chlamydial infection causes serious complications (that were formerly often thought to be gonococcal), such as epididymitis in young men and salpingitis on young women. It may cause local complications in the eye of the newborn baby and even pneumonia in babies and fatal endocarditis in adults. The diagnosis of NSU should lead to the correct treatment of the male patient and of his sexual partners. It is the promiscuous woman, who does not have a regular sexual partner to report back to her that he has NSU, who is at particular risk of undiagnosed chlamydial infection. Routine genital investigations for chlamydia are particularly indicated in her case. Following the parallel of gonorrhoea, it seems that the use of contact tracers may be an effective method for controlling chlamydial infection.