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Hepatitis E
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Hepatitis E virus (HEV), the major etiologic agent of
enterically transmitted non-A, non-B hepatitis worldwide, is a spherical,
non-enveloped, single stranded RNA virus that is approximately 32 to 34 nm
in diameter.
Based on similar physicochemical and biologic
properties, HEV has been provisionally classified in the Caliciviridae
family; however, the organization of the HEV genome is substantially
different from that of other caliciviruses and HEV may eventually be
classified in a separate family.
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Incubation period: |
Average 40 days
Range 15-60 days |
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Case-fatality rate: |
Overall, 1%-3%
Pregnant women, 15%-25% |
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Illness severity |
Increased with age |
- HEV is transmitted primarily by the fecal-oral
route and fecally contaminated drinking water is the most commonly
documented vehicle of transmission.
- Hepatitis E is most commonly recognized to
occur in large outbreaks, HEV infection accounts for >50% of acute
sporadic hepatitis in both children and adults in some high endemic
areas.
- Risk factors for infection among persons with
sporadic cases of hepatitis E have not been defined. Unlike hepatitis A
virus, which is also transmitted by the fecal-oral route,
person-to-person transmission of HEV appears to be uncommon.
- Nosocomial transmission, presumably by
person-to-person contact, has been reported to occur.
- Outbreaks of hepatitis E have occurred over a
wide geographic area, primarily in developing countries with inadequate
environmental sanitation.
- The reservoir of HEV in these areas is
unknown.
- The occurrence of sporadic HEV infections in
humans may maintain transmission during inter-epidemic periods, but a
nonhuman reservoir for HEV is also possible.
- Prevention of hepatitis E relies primarily on
the provision of clean water supplies
- No products are available to prevent hepatitis E
- IG prepared from plasma collected in
non-HEV-endemic areas is not effective in preventing clinical disease
during hepatitis E outbreaks and the efficacy of IG prepared from plasma
collected in HEV-endemic areas is unclear
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