HTLV-II SEROPREVALENCE IN PYGMIES ACROSS AFRICA SINCE 1970

HTLV-II-specific antibodies, with patterns similar to those in the Ame ricas, were present in sera collected about 1970 from Bambuti pygmies in Zaire (14/102; 14%) and from pygmies in Cameroon (5/214; 2.3%), and were more prevalent than HTLV-I. In the Central African Republic, 504 pygmies were HTLV negative. After finding of 4 HTLV-II seropositives among 12 Bambuti pygmies sampled in 1991, this establishes that HTLV-I I or a related retrovirus is present as an ancient endemic in some, bu t not all, insulated groups of African pygmies, similar to the HTLV-II distribution in Amerindian populations. The endemic among the oldest inhabitants of central Africa, and the occasional and scattered occurr ence of apparent HTLV-II among predominant HTLV-I in other Africans, f it well with an ancient African virus and not with importation from th e New World. Theories on the origin and evolution of the primate T-lym photropic viruses (PTLVs) should take into account the longstanding pr esence of HTLV-II-type viruses in both the Old and New World. Present serology suggests identity of the African viruses with HTLV-II, but th eir assignment to a new HTLV type is open should genetic analysis show strong divergence from American HTLV-II. Clinical expression, if any, remains to be studied.