HTLV-II and a new endemic area for HTLV-I in Brazil

Abstract

Human T-cell leukemia virus type one (HTLV-I) is associated with adult T-cell leukemia/ lymphoma (ATL) and tropical spastic paraparesis (TSP). HTLV-I is endemic in Southwestern Japan, Central Africa, and the Caribbean basin. Human T-cell leukemia virus type two (HTL V-Il), another virus related to HTLV-I, has been linked to two cases of an atypical variant of hairy cell leukemia4. HTLV-II has been identified in IV drug abusers in the United States7.HTLV-I infection has also been reported in some populations in Brazil1 2 5 .Salvador, the capital of the State of Bahia, is a city of nearly two million inhabitants, and until 1763 was the major site of slave trade in Brasil. Like the Caribbean basin, the population in Bahia is roughly 80% black or racially mixed. We studied the prevalence of HTLV-I and HTLV-II in several groups in Salvador and another inner city in Bahia, Jacobina.During 1990, sera were obtained from the following groups: 1) a random cross section of 129 patients admitted to a hospital which cares for the lower socio-economic classes; 2) 90 patientes with tuberculosis: 3) 88 patients with AIDS; 4) 14 patients with myelopathy; 5) 16 patients with leukemia/lymphoma; 6) 90 blood donors; 7) 90 pregnant women; 8) 103 health care workers and 9) 44 healthy adults from Jacobina, an endemic area for leishmaniasis.Antibodies to HTLV-I/II were detected with a commercially available enzyme immunoassay (EIA) (Coulter Laboratories, Hialeah, FL). EIA This study demonstrated a relatively high prevalence of antibody to HTLV-1 (1.8%) among adults representig the general population in Bahia (Table 1). This rate is higher than that reported in blood donors in the United States (0.025%) 10, and in Britain (0.01 %)9. And, it is similar to antibody rates observed in African population in Gabon (3.9%), Kenya (1.7%), Liberia (1.6%), Nigeria (2.6%), Senegal (1.2%) and Zaire (3.2% )3. This similarity, presumably, reflects the African origin of the population in Bahia.A high prevalence of HTLV-I infection was detected among patient groups, regardless of whether their diseases were HTLV-I related or not. There was a higher prevalence of HTLV-I infection in tuberculosis patients (11%) compared with the healthy population (1.8%), p< 0.001. However, it remains to be determined whether active tuberculosis, through transient immunosupression and/or antigenic T-cell stimulation causes a recrudescense of latent HTLV-I infection previously undetectabel serologically; or whether HTLV-I cause a general or specific defect which favors reactivation of tuberculosis among tuberculous infected persons. Further studies are needed to assess these hypotheses.HTLV-I induced mitogenic stimulation increases the HIV-1 production from the peripheral blood leukocytes in vitro11. The increased serop re valence 141