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Background: Studies conducted mainly in industrialized countries have shown that the transmission of hepatitis C virus (HCV) is mainly parenteral, and have emphasized the role of nosocomial transmission. In Equatorial Africa, the respective contributions of parenteral and non-parenteral routes of transmission are unknown. The potential role of sexual transmission in this area of high HCV endemicity, where sexually transmitted infections (STI) are frequent, is suggested by the fact that HCV infection is rare in infants and young adolescents, but increases thereafter with age. The present study, conducted in Democratic Republic of Congo, was designed to determine the prevalence of HCV infection and associated sexual risk factors in two female populations with different sexual behaviour.Methods: Cross-sectional studies conducted among commercial sex workers (CSW; n = 1144) and pregnant women (n = 1092) in the late 1980s in Kinshasa showed a high frequency of at-risk sexual behaviour, STI and human immunodeficiency virus (HIV) infection, particularly among CSW. We screened samples collected during these epidemiological studies for antibodies to HCV using a second-generation ELISA with confirmation by a third-generation LIA. We also assessed sociodemographic variables, medical history, STI markers and sexual behaviour, and their potential association with HCV infection.Results: The overall prevalence of anti-HCV was 6.6% (95% CI : 5.2-8.2) among CSW and 4.3% (95% CI : 3.2-5.7) among pregnant women (age-adjusted OR = 1.5, 95% CI : 1.0-2.1, P = 0.05). Multivariate analysis showed that the presence of anti-HCV among CSW was independently associated with a previous history of blood transfusion (P < 0.001), age >30 years (P < 0.001) and the presence of at least one biological marker of STI (P < 0.03). No such links were found among pregnant women (although the history of blood transfusions was not investigated in this group). Anti-HCV was not associated with sociodemographic variables or sexual behaviour in either group, or with individual markers of STI. Despite the high-risk sexual behaviour and the higher prevalence of STI in CSW, the difference in HCV seroprevalence between CSW and pregnant women (6.6% versus 4.3%) was small, particularly when compared with the difference in the seroprevalence of HIV (34.1% versus 2.8%).Conclusion: The role of sexual transmission in the spread of HCV seems to be limited. Parenteral transmission (including blood transfusion and injections), possibly related to the treatment of STI, probably plays a major role. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]