Diagnostic utility of urethral smears in predicting urethral chlamydia in HIV-infected men

We collected data from 218 HIV-infected men to assess the usefulness of the urethral smear and symptoms in predicting Chlamydia trachomatis infection. Prevalence of urethral chlamydia was 9%. A polymorphonuclear leucocyte (PMNL) count ≥5 was 73% sensitive and 71% specific for C. trachomatis infection. Adjusted odds ratio for risk of chlamydial infection was significant for urethral irritation (7.48; 1.54-36.4), a PMNL count of 20 or more (9.83; 2.52-8.4) and a PMNL count of 5-19 (4.10; 1.34-12.5). We had to perform 50 urethral smears in HIV-positive men without symptoms to treat one case of C. trachomatis at the time of visit. Findings suggest that the presence of symptoms, in particular urethral irritation may be associated with chlamydial urethritis and that the higher the urethral PMNL count, the more likely it is for C. trachomatis to be detected. The findings in this study also lend further support to recent guidelines that urethral microscopy is not useful in asymptomatic men and hence should be abandoned.