Hepatitis A: Epidemiology, Natural History, Unusual Clinical Manifestations, and Prevention

Abstract

Hepatitis A virus (HAV) is a positive-strand RNA virus that is transmitted feco-orally through person-to-person contact. Outbreaks are often linked to poor sanitation, overcrowding, or food and water contamination. Infection is often asymptomatic in children, but adults present with jaundice, abdominal pain, hepatitis, and hyperbilirubinemia. Diagnosis is through detection of immunoglobulin M antibodies against HAV, and treatment is supportive. Vaccination is the mainstay of prevention and should be given before exposure whenever possible.

Keywords: Acute liver failure; Hepatitis A outbreak; Hepatitis A prevention; Hepatitis A vaccine; Hepatitis A virus.

Fig. 1.

Effects of HAV exposure in immunocompetent and immunosuppressed patients. Patients immunized against HAV before exposure can clear the virus via preformed neutralizing antibodies. Nonimmune patients who are immunocompetent typically clear the virus after the infectious hepatitis, whereas immunosuppressed patients may sustain a chronic viremia. In rare cases, both immunocompetent and immunosuppressed hosts may manifest an unusual presentation of HAV, including but not limited to liver failure, relapsing hepatitis, and prolonged cholestasis.