Clinical Information

Hepatitis A is caused by infection with the hepatitis A virus. HAV is a 27 nonometer single-stranded, nonenveloped, RNA virus that is classified as a picornavitus. Transmission of heptatitis A is usually via the fecal-oral route and infection occurs mainly due to contaminated food or poor sanitary conditions. Hepatitis A replicates in the liver and the virus is excreted in the bile and shed in the stool. The average incubation period is 30 days with a range of 15 to 40 days. Symptoms last approximately two weeks and include hepatomegaly, jaundice, dark urine, fatigue and gastrointestinal distress such as anorexia, nausea, vomiting, and abdominal pain. At the onset of symptoms resulting from HAV infection, antibody to HAV is detectable. The early antibody response is largely compromised of IgM antibody subclass. Anti-HAV IgM is detectable usually for 3 to 6 months after onset of illness, whereas anti-HAV IgG can persist indefinitely.