Prevalence and risk determinants of HIV-1 and HIV-2 infections in pregnant women in Bissau

Objectives : To analyse the risk determinants of HIV-1 and HIV-2 infections in pregnant women in Bissau. Methods Pregnant women attending the antenatal clinics of Bissau between January 2002 and June 2006 were consecutively tested unless they opted out. Results Among 23,869 tested women the overall prevalence of HIV-1 was 5.7%, that of HIV-2 was 2.4%, and these included the 0.7% prevalence of HIV-1 and HIV-2 duals. The main factors associated with the risk of HIV-1 infection were older age, occupation and number of sexual partners. Beafada and Mandinga ethnic groups were at greater risk of presenting HIV-1, and Bijago and Papel at lower risk. The factors associated with the risk of HIV-2 were age, literacy and occupation; the Beafada were at greater risk than the other ethnic groups. Conclusions : The prevalence of HIV-2 infection decreased overtime, whereas that of HIV-1 infection remained substantially stable, but was higher than that observed in previous studies. The rapid decline in the rates of HIV-2 infection suggests that many of the factors that allowed its exponential growth in the past have now been partially removed, and that sexual and vertical transmission have not been sufficient to maintain and extend the epidemic.