Non-A, non-B hepatitis among participants in a plasmapheresis stimulation program.

Non-A, non-B hepatitis was transmitted to seven of nine participants in a red blood cell-stimulation program following transfusion of blood from one asymptomatic donor. Five of the seven patients had clinical as well as biochemical evidence of infection, and three of these five were icteric. Incubation periods for the clinical cases ranged from 28 to 50 days, and duration of illness was from two to eight weeks. None of the seven patients showed serologic evidence of acute infection or reinfection with hepatitis A virus, hepatitis B virus, cytomegalovirus, or Epstein-Barr virus. Viremia persisted in the donor for at least 34 days, since non-A, non-B hepatitis was transmitted to program participants during that period.