Seroprevalence of HTLV-I and HTLV-II among Intravenous Drug Users and Persons in Clinics for Sexually Transmitted Diseases

HUMAN T-cell lymphotropic viruses Type I (HTLV-I) and Type II (HTLV-II) are closely related retroviruses. 1 HTLV-I is associated with adult T-cell leukemia and with myelopathy or tropical spastic paraparesis. 2 HTLV-II, first isolated from a patient with a variant of hairy-cell leukemia, has not been consistently associated with any specific disease. Seroreactivity to HTLV has been well documented among intravenous drug users in several major U.S. metropolitan areas. 3 , 4 Reported seroprevalence rates in intravenous drug users have ranged from 2 percent to 49 percent. These rates are difficult to compare, however, because of differences in study design, in sampling schemes, in the . . .