HTLV-I and HTLV-II in Africans.

Human T-cell lymphotrophic virus type I (HTLV-I) is the aetiological agent of adult T-cell leukemia (ATL) and tropical spastic paraparesis/HTLV-associated myelopathy (TSP/HAM). It is endemic in Japan, the Caribbean basin and Africa. Unlike HTLV-I, HTLV-II, a closely related retrovirus, has not been formally linked with any disease and its epidemiology has not been established yet. HTLV-II has been observed in a high prevalence among US and European injecting drug users, and among certain Amerindian tribes. A number of studies have pointed out that HTLV-I is widespread in Africa and HTLVII is also present but with a lower prevalence in that continent.' In a previous report,2 we pointed that misdiagnosis of HTLV-II can be frequent using HTLV-I viral lysate screening assays. More recently, Weiss3 noticed this phenomenon testing intravenous drug addicts from New Jersey (USA). In this form, HTLV-II seroprevalence in Africans could be underdiagnosed. An option to avoid false negative results for HTLV-II infection could be to add either an HTLV-II viral lysate or specific recombinant