1. Chiron Corporation, Emeryville, CA 94608.
2. Centers for Disease Control, 1600 Clifton Road NE, Atlanta, GA 30333.
3. Department of Transfusion Medicine Clinical Center, National Institutes of Health, Bethesda, MD 20205.
4. Department of Medicine, University of Southern California, Liver Unit, Rancho Los Amigos Medical Center, Downev, CA 90242.
5. Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD 20205.
6. National Institute of Health, 10-35, 2-Chome, Kamiosaki, Shinagawa-Ku, Tokyo 141, Japan.
7. Gastrointestinal Unit, Massachusetts General Hospital, Boston, MA 02114.
8. Laboratory of Epidemiology, New York Blood Center New York 10021.
9. Community Blood Center of Greater Kansas City, Kansas City, MO 64111.
10. Divisione di Gastroenterologia, Ospedale Maggiore di S. Giovanni Battista, Molinette, Torino, Italy.
11. Instituto di Medicina Interna, Clinica Medica 3, Universita di Milano, Via Pace, 9, 20122, Milan, Italy.