IDENTIFICATION AND MOLECULAR CHARACTERIZATION OF HUMAN T LYMPHOTROPICVIRUS TYPE-II INFECTIONS IN INTRAVENOUS DRUG-ABUSERS IN THE FORMER SOUTH VIETNAM

Previous serological studies have demonstrated that some 60% of intrav enous drug abusers (IVDAs) in urban areas of the former South Vietnam are infected with HTLV-II. In the present report we have attempted to characterize the viruses using restriction fragment length polymorphis m (RFLP) and nucleotide sequence analysis of the provirus long termina l repeat (LTR) region, RFLP analysis of nine samples demonstrated that all were infected with the HTLV-IIb subtype. The HTLV-IIa subtype was not detected, Phylogenetic analysis of the nucleotide sequences demon strated that the viruses clustered closely with HTLV-IIb isolates pres ent in IVDAs from the New York City area. The present molecular analys is together with the previously reported absence of HTLV-II infection in North Vietnam supports the view that HTLV-II may have been introduc ed from the United States to this part of Asia by military personnel d uring the Vietnam conflict.