Hepatitis A
An overview of viral hepatitis, including a table comparing the clinical features of hepatitis A, B, C, D and E, is provided here.
Infection with hepatitis A virus (HAV) causes acute viral hepatitis; it does not progress to chronic hepatitis. Worldwide, most infection results from exposure to contaminated food or water. In high-income countries, most infection is transmitted from person to person, though occasionally community outbreaks (eg associated with a common food source) are reported. Recent outbreaks in Australia have included foodborne (eg from contaminated imported frozen berries) and person-to-person spread (eg between men who have sex with men, people who inject drugs). Notification of hepatitis A infection to public health authorities by the diagnosing clinician is required in all Australian jurisdictions1.
Vaccination or previous exposure to hepatitis A virus provides long-term immunity. Vaccination is recommended for anyone at risk of hepatitis A due to travel, lifestyle or occupation, and for those at greater risk of severe or fulminant hepatitis (eg people with pre-existing chronic liver disease). For further information on immunisation against hepatitis A virus, see the Australian Immunisation Handbook.
The time from exposure to clinical manifestations of hepatitis A infection averages 30 days (range 15 to 50 days). Symptoms are nonspecific and include jaundice, anorexia, nausea, vomiting, abdominal pain and mild fever. Diagnosis is confirmed by identifying HAV immunoglobulin class M (IgM) antibody during acute illness, or detection of HAV RNA in blood or stool using polymerase chain reaction (PCR) testing. Jaundice usually resolves after an average of 6 weeks (range 1 to 10 weeks). Older adults and people with pre-existing chronic liver disease are more likely to develop severe or fulminant hepatitis.
There is no specific treatment for hepatitis A; general supportive care forms the basis of treatment.