The causes and effects of hepatitis A
Wednesday, May 31, 2006
Wellness Wisdom By
Dr. Ghulam Dostzada
Hepatitis A is caused by infection with HAV. The incubation period of HAV is 15 to 50 days, with a mean of approximately 30 days. In infected poeple, HAV replicates in the liver, is excreted in the bile, and is shed in the stool.
Peak infectivity occurs during the two weeks before onset of jaundice or elevation of serum liver enzymes, when the concentration of virus in stool is highest. The concentration of virus in stool declines after jaundice appears. Children may excrete virus for longer periods than do adults. Viremia occurs soon after infection and persists though the period of serum liver enzymes.
The clinical course of hepatitis A typically begins with an abrupt onset of fever, malaise, anorexia, nausea and vomiting, abdominal pain, and dark urine. Children aged less than six years of age are often asymptomatic; however, symptomatic illness with jaundice occurs over 70 percent of older children and adults. Although most people recover within two months, each year approximately 100 people die of severe hepatitis in the United States. This rate is highest among people older than 49.
Transmission is most common in close physical contact, other transmission methods are, blood exposure such as injection drug use, although screening of blood products for hepatitis A has essentially eliminated the already extremely low risk associated with blood transmission.
