Section 1. GENERAL
Hepatitis is an inflammation of the liver. It can be caused by infectious agents
that include certain viruses, bacteria, or other infectants. Hepatitis can also be caused
by toxic agents to include poisons such as carbon tetrachloride and other industrial
solvents, minerals (such as phosphorus), anesthetics, antibiotics, and certain drugs.
Excessive indulgence in alcohol can also be toxic.
In 1964, Blumberg was searching for a type of genetically controlled serum
antigen. He was searching because those persons who have had many transfusions
can develop antibodies against these antigens. During his search, he combined the
serum of a person suffering with hemophilia, who had received many transfusions, with
the serum of an Australian aborigine. Material from the Australian's serum was
precipitated. This material he labeled "Australian antigen." In a few years, the
presence in the serum of this antigen was demonstrated to be frequently associated
with a long incubation hepatitis. The antigen was then labeled "hepatitis-associated
antigen" (HAA). This antigen in a person's serum is also associated with the ability of
the person's blood to transmit hepatitis. For this reason, blood banks quickly set up
facilities to screen all donors for the presence of this antigen in their blood. About 30
percent of the donors who are capable of transmitting hepatitis can be identified by this
testing. With technical refinements in testing methods, there may be a more complete
identification of infection donors. By demonstrating the existence of HAA, we have
gained a greater understanding of the varieties of hepatitis. HAA appears to be mostly
associated with the long incubation or serum hepatitis. Some cases of sporadic
hepatitis and infectious hepatitis have HAA in their serum. This has shown that the
agent for serum hepatitis can be transmitted by other than the parenteral route. It is
probably spread by the fecal-oral route. The HAA has been seen in the feces and urine
of some hepatitis patients. Presently viral hepatitis is separated into short incubation or
infectious hepatitis and long incubation or serum hepatitis varieties.
a. There are three major points about hepatitis that most concern us from a
military point of view.
How easily can hepatitis be transmitted from one person to another?