What is the morbidity rate for this disease?
What loss of man-hours can be expected because of hepatitis?
b. These concerns will be addressed in the balance of this lesson. Hepatitis is
the most important infection that attacks the liver and has been recognized as a major
health problem since World War II. Hepatitis is a reportable disease in most states, so
a pool of statistics is being gathered. It is estimated that at least ten percent of all
patients suffer some residual hepatic damage for as long as a year after an attack of
viral hepatitis and that at least two percent have hepatic damage persisting even longer.
Denmark had a large epidemic of viral hepatitis in the 1940s and this country has had
an increase in deaths from chronic disease of the liver in the past fifteen years. The
United States has not researched the issue long enough to determine whether or not
cirrhosis or other severe degeneration of the liver occurs many years after the acute
onset of the disease. Viral hepatitis seems to be most prevalent in low-income areas
where there is crowding and limited sanitation. Susceptibility is highest between the
ages of 6 and 25, but there is a trend toward increased incidence in adults, especially in
the older age groups. Pregnant women are highly susceptible during the second and
third trimesters and the mortality rate is extremely high in the last trimester. Hepatitis
follows a seasonal pattern with more cases occurring in the fall and early winter. There
also seems to be a cyclical pattern. Major outbreaks seem to occur about every seven
years; however, the pattern is not the same in all parts of the country.
TYPES OF VIRAL HEPATITIS
Infectious hepatitis is known as type "A". This form has an incubation period of 2
to 7 weeks with the average about 4 weeks. This is the milder form of the disease.
Serum hepatitis is known as type "B". The incubation time is from 1 to 6 months with
the average running about 3 months. This type is more serious, with similar but more
severe symptoms. There is another type that is termed "nonA/nonB". This type is
caused by a virus which is neither A nor B. The incubation period is from 2 weeks to
3 1/2 months and it can resemble either type A or type B in severity.
Section II. TYPE A HEPATITIS
a. Distribution. Hepatitis is about evenly distributed world- wide. It is not
limited to any particular area or country.
b. Frequency. Infectious hepatitis is commonly seen in children and young
adults of the 15 to 29 age group. It also infects persons in the middle age group who
have escaped infection as children.