Hep A is an RNA virus that spreads by the fecal-oral route. HAV is more prevalent in low socioeconomic areas with lack of adequate sanitation and poor hygienic practices. International travel is the most common risk factor in USA (and Canada).
HAV infection usually results in an acute, self-limited illness and only rarely leads to fulminant hepatic failure in those with underlying liver disease, especially chronic hepatits C infection.
The manifestations also vary with age: HAV is usually silent or subclinical in children. In contrast, infection in adults can vary in severity from a mild flu-like illness to fulminant hepatitis. The incubation period averages 30 days (range 15 to 49 days). Symptoms include fatigue, malaise, nausea, vomiting, anorexia, fever, and right upper quadrant pain followed by dark urine, light stools, jaundice, and pruritus. Lab investigations show marked elevations of serum aminotransferases (usually >1000 IU/dL), bilirubin, and alkaline phosphatase.
Acute HAV infection is diagnosed by the detection IgM anti-HAV in serum.
The treatment is supportive care.
* image: the most widespread hepatitis A outbreak in USA affected 640 people (killing 4) ,in late 2003, was blamed on tainted green onions at a restaurant.
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