Hepatitis E Virus (HEV) Infection

Background

• Hepatitis E virus (HEV) is a cause of viral hepatitis worldwide and is endemic in many parts of the developing world, particularly Africa and Asia.
• HEV is transmitted mainly by the fecal-oral route, and outbreaks have been associated with the consumption of raw or undercooked meat of HEV-infected animals.
• Acute infection typically causes self-limiting hepatitis. Symptoms arise about 2-8 weeks after infection, and are similar to other forms of viral hepatitis, including fever, nausea/vomiting, abdominal pain, and anorexia.
• Fulminant hepatitis due to HEV is uncommon, but most often occurs in pregnant women, solid organ transplant recipients, or other immunocompromised patients.
• A progression to chronic infection and cirrhosis is rare but has been reported in immunocompromised patients.
• Mortality ranges from 0% to 20%, with the highest rate in pregnant women.

Evaluation

• Consider the diagnosis of HEV in any patient with abnormal liver function tests, particularly immunocompromised patients or pregnant women with severe hepatitis.
  • Aminotransferase levels peak, usually around 1,000-2,000 units/L, near symptom onset.
  • Bilirubin levels rise later in the course.
• A diagnosis of acute HEV infection can be confirmed by either serology or reverse transcriptase-polymerase chain reaction (RT-PCR).
  • Immunoglobulin M (IgM) and immunoglobulin G (IgG) appear around the time of the start of symptoms.
    • IgM remains detectable for about 3-12 months.
    • IgG remains detectable for years.
  • RT-PCR can be performed on serum or stool, though sensitivity and specificity vary by viral genotype.
    • Viremia is present about 1 week prior to the onset of clinical symptoms, and for a few weeks thereafter.
    • The virus can be detected in a stool for about 2-3 months after an acute infection.

Management

• The treatment is supportive care.
• Ribavirin may be effective but supportive data is limited to case series.
• The reduction of immunosuppression may aid in clearance in organ transplant recipients.