Background:  Sexually transmitted diseases (STD) increase HIV transmission. In gay men, rectal and urethral infections with chlamydia and gonorrhea may play an especially important role in HIV transmission. Prompt treatment of these STD in persons with recently acquired HIV infection may limit further transmission of both STD and HIV. chlamydia, gonorrhea, and HIV testing are routinely offered to gay men seeking services at the San Francisco Department of Public Health municipal STD Clinic. We hypothesized that the prevalence of chlamydia and gonorrhea would be higher among men with a newly identified HIV infection than those with negative HIV test results, and that it would be frequent enough to warrant presumptive same-day chlamydia and gonorrhea co-treatment for persons with positive rapid HIV test results.

Methods:  The STD Clinic data were analyzed from January 2004 until June 2006. Visits from self-identified gay or bisexual men, who had had an HIV antibody test and at least 1 rectal, pharyngeal, or urethral/urine test for chlamydia or gonorrhea that day were included in the analysis. Prevalence of infection with chlamydia or gonorrhea at any anatomic site was compared for men with positive and negative HIV test results, and χ² tests were performed to determine differences in proportions.

Results:  Inclusion criteria were met by 5029 visits. Men testing HIV⁺ were 2.6 times more likely to be infected with chlamydia (22.7% or 50 of 220 vs 8.9% or 426 of 4809; p <0.0001) and 2.2 times more likely to be infected with gonorrhea (27.3% or 60 of 220 vs 12.3% or 592 of 4809; p <0.0001) compared to HIV^– men. Of HIV⁺ men, 40.9% (90 of 220) and of HIV^– men, 18.8% (906 of 4809) were infected with either chlamydia or gonorrhea (p <0.0001).

Conclusions:   The high prevalence of chlamydia and gonorrhea, regardless of HIV status, highlights the importance of screening for both infections at all exposed anatomic sites. Furthermore, the substantial prevalence of chlamydia and gonorrhea among newly identified HIV⁺ gay men at our STD clinic is similar to prevalence estimates of chlamydia in gonorrhea-infected patients, where presumptive treatment is recommended. Rapid HIV testing is becoming widely available at STD clinics in the United States. Presumptive same-day chlamydia and gonorrhea treatment among gay men with newly identified HIV infection should be studied to limit the further transmission of both STD and HIV.