HTLV-I and HIV-I antibody frequency in thalassemics and drug addicts in southeast Sicily.

HTLV-I (Human T-Lymphotropic Virus Type 1) and HIV-1 (Human Immunodeficiency Virus Type 1) antibodies have been investigated in 702 sera samples from: 259 drug addicts nerve screened for HIV-1 (Group I), 43 drug addicts already identified as HIV-1 seropositive (Group II), 222 thalassemics (Group III) and 178 occasional blood donors (Group IV). The sera, collected from June 1984 to April 1989, were screened a first time with immunoenzymatic test and the samples proving positive were then confirmed by Western blot test. The seropositive frequency with Western blot for anti-HTLV I was 2.7% in Group I and 6.9% in Group II. Of the thalassemics, five of whom had been previously identified as seropositive for HIV-1, and of the blood donors, none proved to be seropositive for HTLV-I antibodies. With regard to HIV-1, a positive antibody response to the Western blot was found in 19.9% of the Group I subjects. Contemporaneous presence of HTLV-I and HIV-1 antibodies was found in five subjects.