Epidemiology of hepatitis b virus infections among injecting drug users: Seroprevalence, risk factors, and viral interactions

"People had had as little as 1/50th cubic centimetre of serum injected subcutaneously and they had developed jaundice ...Was it not possible that some of these syringes might have a little blood from one man who was in a subclinical state of hepatitis, and if it only took 1/50th c. c. to cause jaundice in some cases, might not that minute amount of blood going into the other man be sufficient to produce his jaundice in anything from ten to fifteen weeks?"-Dr. F. O. MacCallum, in response to an address presented to the Medical Society for the Study of Venereal Diseases, March 1943, on the subject of "jaundice in syphilitics" (1, p. 63).