Hepatitis E is an inflammatory liver disease caused by infection with the hepatitis E virus (or HEV). Although the majority of infections do not lead to serious disease the WHO estimates that there are over 3 million people affected per year by symptomatic hepatitis E and about 44’000 deaths, principally in East and South Asia. In Europe, HEV infection tends to be much less severe or asymptomatic.
In Europe, almost all cases are caused through the consumption of undercooked pork or wild boar meat, including salami-type products. A ten-fold increase of HEV cases was observed in EU/EAA countries between 2005 and 2015 and some countries have reported an unusual increase between 2023 and 2024, yet the disease is still not well known to the general public.
Expert Interview
Emma Cunningham
Senior Clinical Scientist, Infection Sciences – Virology
What is hepatitis E?
Hepatitis E virus is a non-enveloped virus with an RNA genome. Infection with hepatitis E virus can range from asymptomatic infection to fulminant hepatitis, particularly in people who are immunocompromised or who have other underlying conditions.
What are the different genotypes of hepatitis E, where can they be found and how are they transmitted?
Hepatitis E virus genotypes 1 and 2 cause endemic disease in the developing world where it is transmitted by the faecal-oral route via contaminated water or food. In the developed world, genotype 3 (and more rarely 4) circulate in animals and can be transmitted to humans via the consumption of raw or undercooked meat, particularly pork and game. Genotypes 5 to 8 are found in animals and there has only been one documented case of human infection with one of these genotypes.
Who should be tested for hepatitis E?
A test for hepatitis E should be carried out in any individual who has symptoms of hepatitis and has negative test results for hepatitis A, hepatitis B, hepatitis C, other viruses which can cause hepatitis and other non-viral causes of hepatitis have been excluded. It is important to test immunocompromised patients who are at risk of chronic infection with genotype 3.
How is hepatitis E diagnosed?
Hepatitis E is diagnosed either by detecting the immune response of the body to the virus using serological methods to detect antibodies or by detecting the viral RNA in blood by molecular techniques.
What are some of the measures that could be taken to prevent hepatitis E?
Genotypes 1 and 2 can be prevented by improving sanitation and the availability of clean drinking water. Travellers to endemic countries should only drink bottled or boiled water to reduce their risk of hepatitis E. In developed countries, infection with genotypes 3 and 4 can be prevented by avoiding raw or undercooked meat.
How can you treat hepatitis E? Is there any vaccine available?
Most people infected with hepatitis E virus recover without treatment, but infections can be serious in pregnant women, people with chronic liver disease, or immunosuppressed individuals (for example transplant recipients); hospital admission may be required in severe cases and should be considered for pregnant women. There is no specific antiviral therapy for hepatitis E infection although antiviral drugs may be given in immunocompromised patients with chronic hepatitis E infection. There is a hepatitis E vaccine which is licenced for use in China and Pakistan only. However, it was used as an outbreak response in South Sudan in 2022.