Presence of Human T Lymphotropic Virus Types I and II in Ghana,West Africa

Abstract

Until recently, HTLV-I was considered to be an Old World virus and HTLV-II was thought to be endemic in the Americas. However, the presence of HTLV-II among Pygmies and other populations of Africa has raised doubts as to whether HTLV-II is primarily a New World virus. The large serosurveys conducted in the urban and rural areas of southern Ghana have identified a 1-2% prevalence for HTLV-I/II. To define the HTLV type, we have used a Western blot assay (HTLV-2.3 blot) that allows simultaneous confirmation and differentiation between HTLVs. Samples (n = 139) were chosen on the basis of previous reactivity with either an enzyme immune assay or r21e-spiked WB results. The WB 2.3 analysis of these specimens identified 55 (40%) to be HTLV positive, 70 (50%) to be HTLV indeterminant, and 14 (10%) to be HTLV negative for HTLV. HTLV seroindeterminant patterns ranged from both gag and env (14 were r21⁺, p24⁺, and/or p19⁺ [all were RIPA negative]) to gag only (21 were p24⁺/p19⁺, 16 were p19⁺, and 7 were p24⁺), and env only (8 were r21⁺ and 4 were rgp46⁺) reactivities. Of the 55 HTLV-positive specimens, 41 were typed as HTLV-I, 9 were HTLV-II, and 5 could not be typed (HTLV-I/II). Of the nine HTLV-II-positive specimens, three were from patients with Burkitt's lymphoma and six were from healthy individuals (two pregnant women) with no obvious risk factors for HTLV-II. Interestingly, two of the infected individuals were children under 13 years of age. Although sexual transmission is unlikely, they may have been infected through breast-feeding. Thus, Ghana can be added to the list of African countries, including Zaire, Gabon, Ethiopia, Somalia, Ivory Coast, and Guinea, where HTLV-II has previously been reported.