Infectious and serum hepatitis remain a significant worldwide health problem. With the increasing use of blood and blood products, the incidence of serum hepatitis has also increased, so much so that the hazard of hepatitis from a single transfusion has been estimated at 0.3% to 4.0%. Although the incidence of infectious hepatitis is not as high here as in endemic areas of Africa and Asia, we are frequently reminded of the pervasive and contagious nature of the disease by institutional epidemics and common source outbreaks as, for example, in mental hospitals and military installations. The yearly reported incidence of hepatitis, which is far short of the true incidence, varies between 25,000 and 100,000 cases in this country. The illness is often protracted and the mortality, even for young healthy people, in 0.1% to 0.3%.
Although there is general agreement resulting from masses of indirect data that both "infectious" and "serum"