c. Mode of Transmission. The most common means of transmission is from a
fecal-oral spread. This happens in a manner similar to that of typhoid fever. Person-to-
person spread is usually limited to close contacts. The virus can also be spread by
contaminated water, food, (especially shellfish), but rarely by the respiratory route.
It may also be contacted through parenteral introduction of virus through blood, blood
products, or equipment. The oral-fecal route transmits the disease easily because virus
is excreted in the feces long before clinical symptoms appear, and it remains for long
periods of time in both those who have the disease and those who are carriers.
Many acute viral infections may mimic the symptoms of infectious hepatitis.
Common examples are infectious mononucleosis, leptospirosis, hepatic amebiasis,
toxic hepatitis, appendicitis, and pneumonia. When the jaundice appears, there is
sometimes a problem making a differential diagnosis since jaundice can have genesis
in other disorders.
SYMPTOMS AND PATHOLOGY
This disease is characterized by random necrosis of liver cells. An inflammatory
mononuclear collects in the liver lobule and sinusoids of involved areas. In most
instances of nonfatal viral hepatitis, regeneration of the liver begins almost with the
onset of the disease. The damaged cells and their contents eventually are removed by
phagocytosis and enzymatic reaction and the liver return to normal. There are several
factors that will influence the course and severity of the disease. The virulence of the
virus is a prime factor. The stronger the virus, the stronger the disease. Prior hepatic
damage is also a factor. If the patient has sustained liver damage before exposure to
the virus, this will make the disease more severe. Some people seem to have natural
barriers or immunity to the virus. Care following the appearance of the symptoms will
also affect the course of the disease. Mostly viral hepatitis is a mild disease and
complete recovery is the rule. During the course of the disease, a tender enlarged liver
is apparent. Other findings can be splenomegaly, posterior cervical adenopathy and
"spider" angiomas. The symptoms of the disease may not be apparent in every case. It
is estimated that for every apparent case of hepatitis, there may be several cases of
asymptomatic or very mild subclinical hepatitis. These cases are not usually detected.
When symptoms do appear, there are usually two states or phases.
a. Preicteric. This stage is usually associated with headache, anorexia, nausea
and vomiting, chills, fever, aches and pains, malaise, and a tender liver. There may
also be fatigue and an upper respiratory flu-like infection. Those patients who smoke
may develop a distaste for tobacco.
b. Icteric. The jaundice appears and lasts for about 2 weeks. The body
temperature often returns to normal but anorexia and nausea remain. There is usually
dark urine and grayish stools. The liver remains tender and perhaps enlarged. The
patient experiences flatulence and may have mild pruritis.