A reappraisal of chlamydial and nonchlamydial acute non-gonococcal urethritis.

A cohort of 112 men presenting with acute non-gonococcal urethritis (NGU) was investigated for the presence of Chlamydia trachomatis. Men with 3 or more episodes of NGU in the preceding 12 months, or who had received treatment for NGU in the preceding 3 months were excluded. C. trachomatis was sought by examination of urethral smears by direct immunofluorescence, and by examination of the centrifuged deposit from a first pass urine (FPU) sample by direct immunofluorescence, IDEIA, and the polymerase chain reaction. Urethral samples from 48 men were positive for CT, and the FPU samples from an additional 7 men were positive by at least 2 assays. With such intensive investigation it is likely that those men identified as chlamydia-negative were genuinely free from the infection. The clinical history and response to treatment of those men who were chlamydia-positive were compared with those of the chlamydia-negative men. They differed in that a larger proportion of the chlamydia-positive men reported having had intercourse with more than one partner in the previous 3 months, and having had fewer previous episodes of NGU. Moreover, in contrast to some previous studies, after one week of treatment with doxycycline, a larger proportion (65%) of the chlamydia-negative men than the chlamydia-positive men (40%) was cured, although the difference was not sustained following later treatment.