Hepatitis A virus causes acute hepatitis A, the symptoms of which are similar to those caused by Hepatitis B virus (HBV) infection.
The incubation period of HAV is 15–45 days, with an average of 4 weeks. It is relatively short compared to long incubation period of HBV infection. Fatigue, nausea, vomiting, fever, hepatomegaly, jaundice, anorexia, and rash are the most common signs and symptoms of the disease. The condition is also associated with passing of dark-colored urine, pale feces, and elevated serum transaminase levels. Hepatitis A virus infec-tion is usually a self-limiting mild disease and in most cases resolves spontaneously in 2–4 weeks. Hepatitis A virus infec-tion confers lifelong immunity to HAV.
Chronic hepatitis or chronic carrier state does not occur with HAV infection. Hepatitis A virus also never causes hepatocellular carcinoma. Acute hepatitis A is relatively more serious and has high mortality in adults than in children. The exact cause for this is unknown. Acute liver failure and cholestatic hepatitis are some of the rare complications. The mortality caused by HAV is very low, approximately 0.01%.