What should we do about screening for genital chlamydia?

Abstract

Chlamydia trachomatis is the world’s most common bacterial sexually transmitted infection, with an estimated 89 million new cases each year.¹ Genital chlamydia poses a major global public health problem because it is a transmissible cause of severe reproductive morbidity, including pelvic inflammatory disease, impaired fertility and ectopic pregnancy in women.² Chlamydia can be cured with antibiotics and transmission prevented by treating sexual partners, but most infections are asymptomatic so they remain undiagnosed. Early diagnosis is possible, with DNA amplification techniques now providing highly sensitive and specific tests³ that are more acceptable to patients than previous methods because they can be performed on non-invasively collected genital specimens. Probably more than any other single factor, these technological advances in chlamydial diagnosis are driving the current health policy debate about the introduction of national chlamydia screening programmes.^{4, 5} But do we have enough evidence about the effectiveness of screening and about the natural history of chlamydial disease to be sure that proposed screening programmes will be the most effective and cost-effective way of preventing the long term consequences of infection?