[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Microbiology](https://durgical.com/en/microbiology/) › [RNA hepatitis viruses](https://durgical.com/en/microbiology/groups/rna-hepatitis-viruses/) › Hepatitis E virus

[Microbiology](https://durgical.com/en/microbiology/) · [RNA hepatitis viruses](https://durgical.com/en/microbiology/groups/rna-hepatitis-viruses/)

# Hepatitis E virus

- Virus
- Non-enveloped (naked)
- Contact
- Exam priority: medium

A virus spread through contaminated water or undercooked meat. It usually clears on its own, but in pregnancy it can cause severe liver failure.

Updated 2026-11-01

Also called: HEV

## Key points

- Non-enveloped hepevirus spread faecal-orally
- High mortality in the third trimester of pregnancy
- Genotype 3 is zoonotic (pigs) and chronic in transplant recipients
- Anti-HEV IgM for acute diagnosis

## At a glance

**Shape**
Icosahedral

**Genome**
Single-stranded, positive-sense RNA

**Envelope**
Non-enveloped (naked)

**Family**
Hepeviridae, genus Paslahepevirus

**Size**
About 27 to 34 nm

## Morphology

- Naked capsid in stool; in blood it circulates wrapped in cell membrane (quasi-enveloped)
- Four main genotypes infect humans

## Transmission

- Faecal-oral, mainly through contaminated drinking water (genotypes 1 and 2)
- Zoonotic: undercooked pork, wild boar or deer meat (genotypes 3 and 4)
- Transfusion and vertical spread, less often

**Reservoir:** Humans (genotypes 1 and 2); Pigs and other mammals (genotypes 3 and 4)

### Isolation precautions

What the care team adds to standard precautions.

**Contact**
Gown and gloves; dedicated equipment. For C. difficile, soap-and-water hand washing.

## Virulence factors

- Immune-mediated liver damage
- In pregnancy, higher risk of acute liver failure through mechanisms still under study
- In immunosuppressed people genotype 3 can persist and cause fibrosis

## Diseases it causes

- Acute hepatitis E; severe in pregnancy and chronic in transplant recipients [Viral hepatitis →](https://durgical.com/en/conditions/viral-hepatitis/)

## Clinical picture

- Self-limited acute hepatitis similar to hepatitis A
- In the second and third trimesters: acute liver failure, fetal loss and maternal death
- Chronic infection in immunosuppressed transplant recipients
- Possible neurological features, such as Guillain–Barré syndrome

## Diagnosis

- Anti-HEV IgM in blood
- RT-PCR on blood or stool, useful in chronic cases or low-endemic areas

## Treatment

Supportive care in the acute form. In chronic infection after transplant, immunosuppression is reduced and ribavirin may be used.

Drug class only; doses and regimens are set by the clinician from the current guideline.

## Prevention

- Safe water and sanitation
- Thorough cooking of pork and game
- A vaccine is approved in a few countries (not available in Colombia)

## Memory aid

E is for "Expecting" and "Eaten": dangerous to pregnant women and hidden in undercooked pork.

## Test yourself

Think of the answer, then tap the question to see it.

## In which patients does hepatitis E carry the highest mortality?

Pregnant women, especially in the third trimester, through acute liver failure.

## Which hepatitis E genotypes are zoonotic?

Genotypes 3 and 4, acquired from undercooked pork or other mammal meat.

## Who can develop chronic hepatitis E?

Immunosuppressed people, above all organ transplant recipients.

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## Related

- [Hepatitis A virus](https://durgical.com/en/microbiology/hepatitis-a-virus/)

## Related conditions

- [Viral hepatitis](https://durgical.com/en/conditions/viral-hepatitis/)

## What the colours mean

**Gram-positive**
Thick peptidoglycan wall: stains purple.

**Gram-negative**
Thin wall with an outer membrane: stains pink.

**Acid-fast**
Lipid-rich wall (mycobacteria): Ziehl–Neelsen stain.

**Contact**
Gown and gloves; dedicated equipment. For C. difficile, soap-and-water hand washing.

**Droplet**
Surgical mask within about a metre; single room.

**Airborne**
N95 respirator and a negative-pressure room.

[← Back to the group: RNA hepatitis viruses](https://durgical.com/en/microbiology/groups/rna-hepatitis-viruses/)

Educational content on microorganisms; not a treatment guide and no substitute for a health professional's advice. No doses are given.

Sources: [Hepatitis E](https://www.who.int/news-room/fact-sheets/detail/hepatitis-e) (World Health Organization (WHO), 2025); [Appendix A: Type and Duration of Precautions Recommended for Selected Infections and Conditions](https://www.cdc.gov/infection-control/hcp/isolation-precautions/appendix-a-type-duration.html) (CDC, 2024).

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Representative model, for educational purposes only.

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