Editor,—Genital infection with Chlamydia trachomatis is highly prevalent and recognised as a major threat to public health.

There is now a wealth of evidence to demonstrate the superiority of DNA amplification techniques over antigen detection and culture.¹ Only one large study has directly compared ligase chain reaction (LCR) with enzyme immunoassay (EIA) on identical clinical material² and no studies have analysed the health economic impact of LCR in a genitourinary medicine (GUM) clinic population.

We studied the diagnostic effectiveness and cost of LCR compared with EIA.

All GUM attendees undergoing sexual health screening were offered the opportunity to participate. Men presenting with dysuria or urethral discharge were defined as symptomatic. Swabs were collected in …