Screening for sexually transmitted diseases in human immunodeficiency virus-positive patients in Peru reveals an absence of Chlamydia trachomatis and identifies Trichomonas vaginalis in pharyngeal specimens

To determine the prevalence of sexually transmitted diseases (STDs), we screened 107 human immunodeficiency virus-positive patients in Peru, where the virus is predominantly sexually transmitted. Patients had multiple risk factors for STDs, and 38% of women and 50% of men had at least 1 STD (gonorrhea, trichomoniasis, herpes simplex, anogenital watts, or syphilis seropositivity). No chlamydial infection was detected, even though infection rates in the general population are 5%-12%. Patients receiving trimethoprim-sulfamethoxazole (TMP-SMZ) for prophylaxis or treatment of respiratory infections were least likely to have cervicitis and/or urethritis (odds ratio, 0.37; 95% confidence interval, 0.15-0.89). Although not optimal treatment, administration of TMP-SMZ is effective against chlamydial infection. We speculate that the use of concomitant medications, such as TMP-SMZ, may be inadvertently preventing chlamydial infection in this population. Another finding was the presence of Trichomonas vaginalis in pharyngeal specimens of 3 men with histories of orogenital activity. This has not been previously reported and requires further study.