HTLV-2B Strains, Similar to Those Found in Several Amerindian Tribes, Are Endemic in Central African Bakola Pygmies.

International audienceBackground. The presence and origin of endemic foci of human T-lymphotropic virus type 2 (HTLV2) infection in Africa remain a matter of debate. Methods. To better appreciate such determinants, we performed a survey of 1918 inhabitants from Cameroon forest areas, including 1051 Bakola Pygmies and 867 Bantus. Results. The overall HTLV-1/2 seroprevalence was 4% (49 cases of HTLV-1 and 27 cases of HTLV-2 infection). Both infections were mainly restricted to the Bakola Pygmies, with surprisingly no HTLV-2 infections in the Bantu population. Both HTLV-1 and HTLV-2 seroprevalences increased with age. There was evidence of ongoing HTLV-2 transmission in this population. Lymphoid T cell lines producing HTLV-2 were established. HTLV-2 long terminal repeat sequences (672 base pairs) obtained from 7 infected Bakola were highly similar to each other (