Extra-ocular chlamydial infection. WHO Working Group.

Chlamydia trachomatis, the causative agent of trachoma, affecting hundreds of millions of people, is now recognized as a major cause of sexually transmitted disease. In many countries chlamydial infection now outstrips gonorrhoea as the major cause of genital tract infection. Chlamydial urethritis and cervicitis are frequently complicated by ascending infection involving the endometrium, the fallopian tubes and epididymis. This often results in serious reproductive sequelae, e.g., infertility in the female and ectopic pregnancy. Extra-genital manifestations of chlamydial infection may occur involving the eyes (follicular conjunctivitis), joints (arthritis), and distal intestinal tract. Infection of the newborn child during birth may result in ocular or lung disease.There is need for further research on chlamydial infection, with the involvement of a number of different fields including medicine, epidemiology, microbiology, immunology, molecular genetics and operational research. The role of chlamydia has also to be defined in a variety of clinical syndromes for the development of improved diagnostic reagents and vaccine and the production of improved control and intervention strategies.