Decline in sexually transmitted disease prevalence in female Bolivian sex workers: impact of an HIV prevention project.

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 > or = 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 (Cl), 0.41-0.97], syphilis (OR, 0.39; 95% Cl, 0.23-0.64), and trichomoniasis (OR, 0.44; 95% Cl, 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.