The occurrence of jaundice in American and British troops and in the natives of Brazil following administration of yellow fever vaccine was a serious problem early in the war. Elimination of the human serum in the preparation of the vaccine prevented such jaundice, which was demonstrated to be of hepatic and not of hemolytic origin. The hepatitis or the syndrome of "homologous serum jaundice" presented as a constant feature the long interval between the injection of a human blood product and the appearance of jaundice. The incubation period is sixty to ninety days. The nature of the icterogenic factor in the human serum has not been determined, although many believe it to be a virus.
Bigger1 has concluded that jaundice in syphilitic patients who receive intravenous arsenicals is due to transmission of a virus from patient to patient and not to the toxic effect of the arsenical on the