Retroviral epidemics in Guinea-Bissau: HIV-1, HIV-2, and HTLV

Studies of HIV in Guinea-Bissau began in 1987 estimating an HIV-2 prevalence of 9% in adults above 14 years in urban Bissau. No HIV-1 infection was found at that time. The first case of HIV-1 infection was identified in 1989, when one case of dual infection of HIV-1+HIV-2 was detected. Over the last 20 years the two viruses have shown a different pattern of spread in the country; the prevalence of HIV-2 seems to be stabilising or decreasing, while HIV-1 prevalence has been increasing gradually [208]. In contrast to neighbouring countries, Senegal and GuineaConakry, with a low HIV-1 prevalence (<1 and 1.5%, respectively), Guinea-Bissau has a prevalence comparable to the levels of the most affected countries in the sub-region (Côte d‘Ivoire, Nigeria and Mali) with an HIV-1 prevalence higher than 4%. Results