Prevalence and risk factors of cervicovaginal HIV shedding among HIV-1 and HIV-2 infected women in Dakar, Senegal.

OBJECTIVES: To assess the risk determinants and prevalence of cervicovaginal shedding of HIV-1 and HIV-2 among women in Dakar, Senegal.
METHODS: We conducted a cross sectional study of 153 HIV seropositive female sex workers (FSW) and another 142 HIV seropositive women attending an infectious diseases unit, based on an interview, physical examination, and laboratory screening for major sexually transmitted infections (STI). Cervicovaginal lavage fluid was tested for HIV-RNA by means of nested PCR. Links between cervicovaginal shedding of HIV-1 and HIV-2 and sociodemographic, clinical, and laboratory variables were identified by using odd ratios and 95% confidence intervals. Logistic regression analysis was used to identify independent links with HIV shedding.
RESULTS: The detection rate of HIV-RNA in cervicovaginal lavage fluid was low among FSW, with no difference between HIV-1 (7/90: 8%) and HIV-2 (3/48: 6%). The rate was far higher among the other women (41%, 48/117; 33%, 7/21 for HIV-1 and HIV-2, respectively). In multivariate analysis, high plasma viral load (>40 000 copies/ml) (AOR = 2.4 (1.0-5.6) p = 0.04) and basic vaginal pH (AOR = 2.2 (1.3-3.7) p = 0.002) were independently associated with HIV-1 shedding. For HIV-2 a CD4 count < 200 cells x 10(6)/l was the only factor associated with the shedding of HIV-2 (AOR = 9.0 (0.9-93)). The genital shedding rate was higher with HIV-1 than with HIV-2 (OR = 2.1 (0.9-4.8), but this difference disappeared after adjustment for the CD4+ cell count (AOR = 1.2 (0.5-2.9)).
CONCLUSION: Advanced disease stage and immunosuppression are the major risk determinants for shedding of both HIV-1 and HIV-2. Basic vaginal pH is also a risk determinant for HIV-1 shedding.