Antiretroviral therapy among HIV-1 infected female sex workers in Benin: a comparative study with patients from the general population

Objective:
The aim of this study conducted in Benin was to compare HIV-1 infected female sex workers (FSW) and patients from the general population (GP) to see whether there was a difference in adherence level, mortality rate and immuno-virologic response to antiretroviral therapy (ART).
Methods:
Fifty-tree FSW and 318 patients from the GP were recruited and followed for at least one year. We compared both cohorts according to poor-adherence (taking <95% of the pills), CD4 count increase, undetectable viral load (VL; ≤50 copies/mL) and crude mortality rate. We constructed a multivariate regression model to assess factors associated with undetectable VL.
Results:
During the first year, the proportion of FSW with poor-adherence was significantly higher than that of the GP patients (19.3% versus 7.5%; p < 0.0001) and median gain in CD4 count among FSW was slightly lower (103/mm3 versus 129/mm3; p = 0.085). In the multivariate model (including CD4 at ART initiation and the sub-cohort i.e. FSW vs GP patients), duration under ART (p = 0.003) as well as CD4 count at enrolment in the study (p < 0.0001) and good-adherence (0.057) were independently associated with undetectable VL. When adherence was withdrawn from this model, there was a borderline significant association between detectable VL and being a FSW (p = 0.074). The crude mortality rate was 1.11 per 100 persons-years among the GP patients and 4.65 per 100 persons-years among FSW.
Conclusion:
Response to ART was lower among FSW compared to GP patients, as a result of poorer adherence. Specific behavioural interventions are needed to improve adherence and response to ART among FSW.