Viral hepatitis has been recognized as an illness since antiquity. However, it was not until World War II that it was realized that this disease was a commonplace entity. On the basis of epidemiologic data, it was believed that there were two distinct types of viral hepatitis: hepatitis A, or infectious hepatitis, contracted by oral exposure and with a short incubation period (15 to 45 days), and hepatitis B, or serum hepatitis, caused by parenteral exposure and with a long incubation period (50 to 180 days). Recent investigation has shown that (1) other infectious diseases may mimic viral hepatitis (cytomegalovirus, EB virus, toxoplasmosis, infectious mononucleosis), (2) hepatitis A and B may be transmitted by either the oral or the parenteral routes, and (3) there is at least one additional cause of viral hepatitis (hepatitis “C”?), which has an incubation period intermediate to those of hepatitis A and B. The development of immunologic methods for the identification of these diseases during the past decade has permitted these advances.… The following are highlights of recent investigations.
Conrad ME, Knodell RG. Viral Hepatitis—1975. JAMA. 2014;312(6):654. doi:10.1001/jama.2013.279664