Abstract
Objective. To identify biological and behavioral factors that predict HIV infection and determine the proportion of HIV infection that were attributable to different exposures among female Commercial Sex Workers (CSWs) of varying ethnic background.Method. A nested case-control study was conducted among 114 (53 cases and 61 controls) female CSWs in Georgetown, Guyana. A subset of data, devoid of personal identifiers, was extracted from a cross-sectional survey which collected baseline data for the evaluation of an intervention in this population. Association between exposure variables and the outcome were tested using multiple logistic regression analysis, controlling for age group and place of work. Predictors of HIV infection were identified using stepwise forward logistic regression analysis. Separate sub-group analyses were conducted to identify risk factors for HIV infection in the different ethnic groups. Adjusted odds ratios and 95% confidence intervals were calculated.Results. CSWs of African/mixed descent were four times more likely to be HIV infected compared to those of Indian descent (Adj. OR = 4.14; 95% CI: 1.45--11.85). HIV risk was higher among CSWs with ≤3 children (Adj. OR = 3.76; 95% CI: 1.34--10.55); ≥5 clients per night (Adj. OR = 3.49; 95% CI: 1.34--9.12); current syphilis (Adj. OR = 6.96; 95% CI: 2.6--18.63); and a history of syphilis (Adj. OR = 3.97; 95% CI: 1.56--10.14). No significant interaction was found between current syphilis and past syphilis. Independent predictors of HIV infection were African/Mixed ethnicity (Adj. OR = 6.05; 95% CI: 1.49--24.58); current syphilis (Adj. OR = 8.80; 95% CI: 2.39--32.49) and PID (Adj. OR = 3.15; 95% CI: 1.04--9.57). Number of clients per night (≥5); age at first sex (≤16 years); and syphilis (current and past) were associated with HIV infection among CSWs of African/Mixed descent. For those of Indian ethnicity current syphilis and crack-cocaine use were associated with HIV infection.Conclusion. In this study, ethnicity emerged as an independent predictor of HIV infection among female CSWs with those of African/mixed descent having a higher risk of infection. STDs also seem to be playing a major role in HIV spread in this population.