Inflammation of the liver caused by the hepa titis A virus
(HAV). HAV is usually transmitted from person to person by food or drink that has
been contaminated with the stool of a person with hepatitis A. This type of transmission
is called "fecal-oral." The virus is more easily spread in areas where there are
poor sanitary conditions or where good personal hygiene is not observed. In 2003
there were hepatitis A outbreaks in the US associated with eating raw or lightly
cooked green onions (scallions). Casual contact, as in a school, office, or another
work setting, does not spread the virus.
Hepatitis A can be transmitted by men (both adolescents and adults) who have
sex with men. Hepatitis A outbreaks among men who have sex with men have been frequently
reported. The virus can also be transmitted by illegal-drug users.
Hepatitis A develops within 2 months of exposure to the virus. The average incubation
period for the virus is 28 days (range: 15-50 days) until symptoms appear. Hepatitis
A can range greatly in severity. Some persons with hepatitis A virus infection have
no signs or symptoms of the disease. Older persons are more likely to have symptoms
than children. In its most dire form, the disease can lead to liver failure and
death. This is relatively rare.
The symptoms and signs tend to appear abruptly and may include fatigue, loss
of appetite, nausea, diarrhea, abdominal pain, fever, and jaundice (yellowing of
the skin and eyes) and dark urine. Symptoms usually last less than 2 months. A few
persons are ill for as long as 6 months. Recovery is usually complete.
The diagnosis of hepatitis A is confirmed by a blood test (IgM anti-HAV). When
immediate protection against hepatitis A infection is needed, immunoglobulin (gamma
globulin) is used. Immunoglobulin is effective only if given within two weeks of
exposure, and protection only lasts for two to four months. Immunoglobulin can be
used to protect household contacts of someone with acute viral hepatitis, and by
travelers who must depart for regions with poor sanitation and high hepatitis A
rates before vaccines can take effect. Travelers can receive immunoglobulin and
hepatitis A vaccine simultaneously.
Hepatitis A vaccine is used before exposure to hepatitis A virus for persons
who are more likely to get the infection or are more likely to get seriously ill
if they do get hepatitis A. The Ceneters for Disease Control & Prevention (CDC)recommend
the hepatitis A vaccine for persons traveling to or working in countries that have
high or intermediate rates of hepatitis A; children in areas where the rates of
hepatitis A were or are at least twice the national average during the baseline
period of 1987-1997; men who have sex with men; injecting and non-injecting illegal-drug
users; persons who work with hepatitis A virus-infected primates or with hepatitis
A virus in a research laboratory setting; people with chronic liver disease; and
persons who have clotting-factor disorders such as hemophilia and who are administered
clotting-factor concentrates such as Factor VIII and Factor IX.
Also called infectious hepatitis, epidemic jaundice. See also hepatitis A immunization.
Common Misspellings: hepititis a, hepatitus a, hepetitis a, hapatitis a
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