Hepatitis E is caused by an
enterically transmitted RNA virus and causes typical symptoms of viral
hepatitis, including anorexia, malaise, and jaundice. Fulminant
hepatitis and death are rare, except during pregnancy. Diagnosis is by
antibody testing. Treatment is supportive.
There are 4 genotypes of hepatitis E virus (HEV). All can cause acute viral hepatitis.
Genotypes 1 and 2 usually cause waterborne outbreaks that
are linked to fecal contamination of the water supply and fecal-oral
person-to-person transmission. Outbreaks have occurred in China, India,
Mexico, Pakistan, Peru, Russia, and central and northern Africa. These
outbreaks have epidemiologic characteristics similar to hepatitis A virus
epidemics. Sporadic cases also occur. No outbreaks have occurred in the
US or in Western Europe. Most cases in the developed world occur in
travelers returning from a developing country, but sporadic cases not
associated with travel have been reported.
Genotypes 3 and 4 typically cause sporadic cases rather
than outbreaks. Transmission is food-borne and can involve eating
uncooked or undercooked meat; cases have been associated with
consumption of pork, deer, and shellfish.
HEV was not originally thought to cause chronic hepatitis,
cirrhosis, or chronic carrier state; however, reports document chronic
genotype 3 hepatitis E exclusively in immunocompromised patients
(including organ-transplant recipients, patients receiving cancer
chemotherapy, and HIV-infected patients).
Symptoms and Signs
Typical manifestations of viral hepatitis occur: anorexia, malaise, nausea and vomiting, and fever, followed by jaundice.
Hepatitis E may be severe, especially in pregnant women; in them, risk of fulminant hepatitis and death is increased.
Diagnosis
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IgM antibody test (when available)
In the initial diagnosis of acute hepatitis, viral hepatitis should be differentiated from other disorders causing jaundice (see figure Simplified approach to possible acute viral hepatitis ). If acute viral hepatitis is suspected, the following tests are done to screen for hepatitis viruses A, B, and C:
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IgM antibody to hepatitis A virus (IgM anti-HAV)
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Hepatitis B surface antigen (HBsAg)
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IgM antibody to hepatitis B core (IgM anti-HBc)
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Antibody to hepatitis C virus (anti-HCV) and hepatitis C RNA (HCV RNA) PCR
If tests for hepatitis A, B, and C are negative but the patient
has typical manifestations of viral hepatitis and has recently traveled
to an endemic area, IgM antibody to HEV (IgM anti-HEV) should be
measured if the test is available.
Treatment
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Supportive care
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For chronic hepatitis E, possibly ribavirin
No treatments attenuate acute viral hepatitis, including hepatitis E.
Preliminary studies suggest antiviral efficacy for ribavirin in treatment of chronic hepatitis E.
Alcohol should be avoided because it can increase liver damage.
Restrictions on diet or activity, including commonly prescribed bed
rest, have no scientific basis.
For cholestatic hepatitis, cholestyramine 8 g orally once or twice a day can relieve itching.
Viral hepatitis should be reported to the local or state health department.
Prevention
Good personal hygiene and standard universal precautions help
prevent fecal-oral transmission of hepatitis E. Boiling water appears to
reduce risk of infection. Because person-to-person transmission is
rare, isolation of infected patients is not indicated.
A vaccine for hepatitis E is now available in China; it is
not available in the US. The vaccine appears to have about 95% efficacy
in preventing symptomatic infection in males and is safe. Efficacy in
other groups, duration of protection, and efficacy in preventing
asymptomatic infection are unknown.
Key Points
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Transmission of hepatitis E is usually by the fecal-oral route.
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Most patients recover spontaneously, but pregnant women have an increased risk of fulminant hepatitis and death.
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Genotype 3 may cause chronic hepatitis in immunocompromised patients.
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Suspect hepatitis E in travelers to endemic regions; do IgM anti-HEV testing if available.
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Treat patients supportively; consider using ribavirin for chronic hepatitis E.
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A vaccine is available in China.
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