virus infection . Genital ulceration secondary to Epstein

common techniques for detecting chlamydial antigen are direct immunofluorescence (DIF) and enzyme immuno-assay (EIA). Examination of first void urine (FVU) samples using EIA to detect C trachomatis antigen appears to be as sensitive as taking urethral swabs for diagnosis in men.2 We have studied chlamydia prevalence in males attending their general practitioners from whom a mid stream urine sample (MSU) was submitted for routine bacteriology for suspected urinary tract infection. Direct microscopy and culture were first performed. Samples which had more than 5 pus cells per high power field but no bacterial growth were tested for chlamydia antigen in an EIA (Dako) and all repeatedly reactive samples were confirmed by DIF using fluorescein labelled monoclonal antibody (Syva, Microtrak). The DIF was read by two observers. A preparation showing at least two