Why would EPA lie in 1989, and today, by claiming Hepatitis A virus cause no infectious disease?
10. Hepatitis A (HAV)--------------------------------------no disease
hepatitis A virus - the virus causing hepatitis A
enterovirus - any of a group of picornaviruses that infect the gastrointestinal tract and can spread to other areas
(especially the nervous system)
Hepatitis A virus (HAV), a major cause of infectious hepatitis in humans, is a positive strand RNA virus belonging to the
hepatovirus group of the picornavirus family. Primary detection of HAV in clinical or biological samples is not routinely
possible at present because wild-type HAV grows very poorly in cell culture. Except for virus preparations that have
been adapted for rapid growth in cell culture, HAV does not produce a detectable cytopathic effect in infected cells.
It is the most common cause of acute viral hepatitis and is particularly common in children and young adults.
Waterborne and food-borne epidemics (Merck)
Hepatitis A is an acute liver disease caused by the hepatitis A virus (HAV), lasting from a few weeks to several months. It
does not lead to chronic infection.
Transmission: Ingestion of fecal matter, even in microscopic amounts, from close person-to-person contact or ingestion
of contaminated food or drinks.
Vaccination: Hepatitis A vaccination is recommended for all children starting at age 1 year, travelers to certain countries,
and others at risk.
Hepatitis A, caused by infection with the hepatitis A virus (HAV), has an incubation period of approximately 28 days
(range: 15–50 days). HAV replicates in the liver and is shed in high concentrations in feces from 2 weeks before to 1
week after the onset of clinical illness. HAV infection produces a self-limited disease that does not result in chronic
infection or chronic liver disease.
However, 10%–15% of patients might experience a relapse of symptoms during the 6 months after acute illness. Acute
liver failure from hepatitis A is rare (overall case-fatality rate: 0.5%). The risk for symptomatic infection is directly related
to age, with >80% of adults having symptoms compatible with acute viral hepatitis and the majority of children having
either asymptomatic or unrecognized infection. Antibody produced in response to HAV infection persists for life and
confers protection against reinfection.
HAV infection is primarily transmitted by the fecal-oral route, by either person-to-person contact or consumption of
contaminated food or water. Although viremia occurs early in infection and can persist for several weeks after onset of
symptoms, bloodborne transmission of HAV is uncommon. HAV occasionally might be detected in saliva in
experimentally infected animals, but transmission by saliva has not been demonstrated.
In the United States, nearly half of all reported hepatitis A cases have no specific risk factor identified. Among adults with
identified risk factors, the majority of cases are among men who have sex with other men, persons who use illegal drugs,
and international travelers.
Because transmission of HAV during sexual activity probably occurs because of fecal-oral contact, measures typically
used to prevent the transmission of other STDs (e.g., use of condoms) do not prevent HAV transmission. In addition,
efforts to promote good personal hygiene have not been successful in interrupting outbreaks of hepatitis A. Vaccination
is the most effective means of preventing HAV transmission among persons at risk for infection. Hepatitis A vaccination
is recommended for all children at age 1 year, for persons who are at increased risk for infection, for persons who are at
increased risk for complications from hepatitis A, and for any person wishing to obtain immunity.