Subsaharian Africa is the most important reservoir of HTLV1 virus but its epidemiology is not well-known. The authors have studied from 1987 to 1990 the situation in 6 countries in Central Africa. The already described routes of transmission are present: through blood transfusions (but it's not such a common practice), heterosexual transmission (but it doesn't seem to be as important as in other continents), and mother to child transmission through breast feeding. Nevertheless, environmental factors--which have to investigated--could play a role for transmission, among them one could think to vectors and parasites.