Diagnosis of infection with human T-lymphotropic virus type II (HTLV-II) in Norwegian HIV-infected individuals.

Sera from 298 HIV-infected individuals from Southern Norway were examined for antibodies against HTLV. 30 sera (10.1%) were HTLV-II positive and 1(0.3%) HTLV-I positive. 25 of the HTLV-II infected subjects were intravenous drug abusers (IVDAs), giving a prevalence of HTLV-II infection of 24.5% in this group. Examination of blood samples by polymerase chain reaction followed by restriction enzyme analysis or sequencing confirmed the serological diagnosis. To evaluate current screening and verification HTLV tests, 44 sera were examined using a gelatin particle agglutination test, 5 different enzyme-linked immunoassays (ELISA) and 4 Western blots (WB). While earlier ELISAs and WBs were inadequate, a recent ELISA and WB including recombinant envelope glycoproteins from both viruses permitted serological diagnosis and distinction between HTLV-I and HTLV-II. Thus, HTLV-II now spreads among IVDAs in a North-European country. Health authorities in other countries should estimate the magnitude of the problem to decide upon measures to avoid transmission through blood transfusion.