Decline in sexually transmitted disease prevalence in female Bolivian sex workers

Objective: To implement an HIV prevention intervention among female commercial sex workers (CSW), and to monitor key outcomes using routinely collected clinical and laboratory data. Design: Cross-sectional and longitudinal analysis of data from an open-enrollment cohort. Setting: One public sexually transmitted disease (STD) clinic and about 25 brothels in La Paz, Bolivia. Participants: A total of 508 female CSW who work at brothels and attend a public STD clinic. Intervention: Improved STD clinical care, supported by periodic laboratory testing, and behavioral interventions performed by a local non-governmental organization. Main outcome measures: Prevalence of gonorrhea, syphilis (reactive plasma reagin titer ≥ 1 : 16), genital ulcer disease, chlamydial infection, and trichomoniasis; self-reported condom use in the previous month; and HIV seroprevalence. Results: From 1992 through 1995, prevalence of gonorrhea among CSW declined from 25.8 to 9.9% (P < 0.001), syphilis from 14.9 to 8.7% (P = 0.02), and genital ulcer disease from 5.7 to 1.3% (P = 0.006); trends in prevalence of chlamydial infection and trichomoniasis were not significant. Self-reported condom use during vaginal sex in the past month increased from 36.3 to 72.5% (P < 0.001). In a multivariate analysis, condom use was inversely associated with gonorrhea [odds ratio (OR), 0.63; 95% confidence interval (CI), 0.41–0.97], syphilis (OR, 0.39; 95% CI, 0.23–0.64), and trichomoniasis (OR, 0.44; 95% CI, 0.32–0.71). In 1995, HIV seroprevalence among CSW was 0.1%. Conclusion: Effective prevention interventions for female CSW can be implemented through public services and non-governmental organizations while HIV rates are still low, and key outcomes can be monitored using data obtained from periodic screening examinations.