Hepatitis A

Hepatitis A is an infectious disease that affects the liver, caused by the hepatitis A virus a non enveloped RNA virus that is classified as a picornavirus. HAV is acquired by mouth (through fecal-oral transmission) and replicates in the liver. The hepatitis A virus is usually caught from food or drink that contains the virus, but is sometimes spread by other means, such as swimming in water contaminated by sewage. Peak titers occur during the 2 weeks before onset of illness. Virus excretion begins to decline at the onset of clinical illness, and has decreased significantly by 7–10 days after onset of symptoms. Most infected persons no longer excrete virus in the feces by the third week of illness. Children may excrete virus longer than adults.

Symptoms of hepatitis A begin 3 to 6 weeks after coming into contact with the virus. These consist of nausea (feeling sick), fever and aches and pains. After a few days the whites of eyes and skin may become yellowish (jaundice). The severity and type of symptoms can vary. Young children may not develop jaundice. Most people recover completely but the illness is usually severe enough to keep people ill for about a month. Clinical illness usually does not last longer than 2 months, although 10%–15% of persons have prolonged or relapsing signs and symptoms for up to 6 months. Virus may be excreted during a relapse.

Hepatitis A cannot be distinguished from other types of viral hepatitis on the basis of clinical or epidemiologic features alone. Serologic testing is required to confirm the diagnosis. Virtually all patients with acute hepatitis A have detectable IgM anti-HAV.

There is no specific treatment for hepatitis A virus infection. Treatment and management of HAV infection are supportive.