Simplification of procedures used to test urine samples for Chlamydia trachomatis.

Two methods of simplifying the procedure for examining urine samples for Chlamydia trachomatis were investigated. When 73 urine samples from 56 men with acute non-gonococcal urethritis were examined by direct immunofluorescence (MicroTrak), centrifuging 1 ml volumes of urine at 13,000 rpm for five minutes was at least as efficient for detecting C trachomatis as centrifuging larger volumes at 3000 rpm for 30 minutes. Furthermore, examination of urine produced during a visit to a sexually transmitted disease clinic was at least as efficient as examination of early morning urine for detecting C trachomatis by MicroTrak, or by an enzyme immunoassay (IDEIA). Both modifications have practical advantages and should encourage the use of urine samples for diagnosing chlamydial infections in men.