Introduction
Hepatits E is an inflammation of the liver caused by the hepatitis E virus (HEV). Hepatitis E is clinically similar to Hepatitis A. Many cases are asymptomatic.
There are an estimated 20 million cases of HEV each year, although only about 3 million of these are thought to be symptomatic. HEV is estimated to cause about 44 000 deaths each year.
Infection is usually self-limiting and lasts between 2-6 weeks before being cleared. Very rarely acute liver failure can develop – which can be fatal. Pregnancy – particularly in the third trimester – is associated with much higher mortality – up to 25%.
It is transmitted via the faecal-oral route – most commonly in contaminated water. HEV is found worldwide but is most common in East and South Asia.
A vaccine against hepatitis E exists in China but has not been licensed elsewhere – as of June 2022.
Aetiology
- Waterborne similar to hep A (shellfish and water melons!). 30% of dogs, rodents and pigs carry the virus – usually without causing any disease
- Common in regions with poor sanitation. In these areas – contamination of water sources may occur and can infect hundreds or thousands of individuals at once.
- In other regions – occasional cases can occur when cases are caught from animals
- There are 4 genotypes – types 1 and 2 are typically waterborne and types 3 and 4 typically circulate in animal populations
Presentation
Very similar to that of any other acute hepatitis:
- Many patients are asymptomatic. They may never know they have had the disease
- Very rarely it can be life-threatening
- May be a prodromal phase
- Jaundice, malaise, abdominal pain, nausea & fever – usually lasting around 2 weeks
- Incubation period is 2-10 weeks (Average of 5-6 weeks)
- Symptoms and cases are generally much more mild in children
Other Factors:
- Generally does not cause chronic disease – but is is possible – usually only seen in iummunocompromised patients
- 25% mortality in pregnancy. Often baby will also die. This does not happen with hep A.
- During an acute infection, IgM antibodies (anti-HEV) are present.
- There is no active or passive immunity to hepatitis E
Diagnosis
- HEV IgM antibodies can be detected in serum
- HEV PCR can also be performed
- Usually testing is only performed once hepatitis A has been excluded
Management
- There is no specific management
- Disease is usually self-limiting
- Immunosupressed patients with chronic hepatitis E may benefit from Ribavarin (an antiviral). Interferon may also be used.
Prevention
Prevention efforts focus around improving sanitation in areas that are high-risk or have an history of outbreaks.
References
- Murtagh’s General Practice. 6th Ed. (2015) John Murtagh, Jill Rosenblatt
- Oxford Handbook of General Practice. 3rd Ed. (2010) Simon, C., Everitt, H., van Drop, F.
- Beers, MH., Porter RS., Jones, TV., Kaplan JL., Berkwits, M. The Merck Manual of Diagnosis and Therapy
- Hepatitis E – WHO
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