HEV/Hepatitis E Virus Infection


What is Hepatitis E?

Hepatitis E is a liver disease caused by the Hepatitis E virus (HEV). HEV infection usually results in a self-limited, acute illness. It is widespread in the developing world. Although rare in developed countries, locally acquired HEV infection can result in acute hepatitis with tendency to progress to chronic hepatitis mainly among solid organ transplant recipients.

How common is Hepatitis E in the United States?

Hepatitis E is believed to be uncommon in the United States. However, some studies have found a high prevalence of antibodies to HEV in the general population. When symptomatic hepatitis E does occur, it is usually the result of travel to a developing country where hepatitis E is endemic. Sporadic Hepatitis E cases not associated with travel have been identified in the United States. No clear exposure was identified for these domestically acquired (non-travel related) cases.

What are the signs and symptoms of Hepatitis E?

When they occur, the signs and symptoms of Hepatitis E are similar to those of other types of acute viral hepatitis and can include:

  • Fever
  • Fatigue
  • Loss of appetite
  • Nausea
  • Vomiting
  • Abdominal pain
  • Jaundice
  • Dark urine
  • Clay-colored stool
  • Joint pain

The ratio of symptomatic to asymptomatic infection ranges from 1:2 to 1:13.

How soon after exposure will symptoms appear?

When symptoms occur, they usually develop 15 to 60 days (mean: 40 days) after exposure.

How long does an HEV-infected person remain infectious?

The period of infectiousness has not been clearly determined, but virus excretion in stool has been demonstrated from one week prior to onset up to 30 days after the onset of jaundice. Chronically infected persons shed virus as long as infected.

How serious is Hepatitis E?

Most people with Hepatitis E recover completely. During HEV outbreaks, the overall case-fatality rate is about 1%. However, for pregnant women, Hepatitis E can be a serious illness with mortality reaching 10%–30% in their third trimester of pregnancy. Hepatitis E could also be serious among persons with preexisting chronic liver disease resulting in decompensated liver disease and death. Similarly high mortality occurs solid organ transplant recipients on immunosuppressive therapy.

Can Hepatitis E become chronic?

To date, there is no report of progression of acute hepatitis E to chronic Hepatitis E in developing countries where HEV genotypes 1 and 2 are the predominant causes of illness. However, more and more cases of Hepatitis E with progression to chronic hepatitis and chronic liver disease are being reported among HEV genotype 3 cases acquired in the developed countries. These chronic cases are exclusively among persons who are on immunosuppressive treatment for solid organ transplant.

Diagnosis and Treatment

How is Hepatitis E diagnosed?

Because cases of Hepatitis E are not clinically distinguishable from other types of acute viral hepatitis, diagnosis can be confirmed only by testing for the presence of antibody against HEV or HEV RNA.

No serologic tests to diagnose HEV infection have been approved by FDA for use in the United States. Several tests are available for research purposes and some commercial laboratories use commercially available assays from other countries.

HEV infection should be considered in any person with symptoms of viral hepatitis who has traveled to a hepatitis E endemic region, recently travelled from an endemic area, or from an outbreak afflicted region and who is negative for serologic markers of Hepatitis A, B, C, and other hepatotropic viruses. A detailed history regarding sources of drinking water, uncooked food, and contact with jaundiced persons should be obtained to aid in diagnosis. There are increasing numbers of domestically acquired cases of hepatitis E and diagnosis should be suspected when no etiology can be identified on thorough evaluation.

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