Prospective study of HIV infection among parenteral drug abusers.

Male heterosexual i.v. drug abusers in methadone maintenance treatment were surveyed for HIV disease and followed prospectively in Richmond, Virginia. Five of 50 (10%) had both positive ELISA and Western Blot antibodies initially, although none had other clinical manifestations. Forty-two (84%) were restudied 1 year later. None had developed clinical manifestations of HIV disease, or seroconverted from negative to positive. Thirty-nine Control i.v. drug abusers seeking methadone or inpatient detoxification showed a similar low seropositivity rate (3%), indicating that Richmond had low endemicity for HIV during the year. An unexpected finding in the followup of the 5 with initial seropositivity was that only 1 retained both ELISA and Western Blot positivity. The difference in serological reaction was unexplained.