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_ RCGP Learning
Hepatitis E: a global, underdiagnosed viral infection
by _ RCGP Learning - Monday, 4 September 2023, 1:22 PM
Anyone in the world

Written by Dr Dirk Pilat

The Hepatitis E virus (HEV) is the most common cause for acute viral hepatitis worldwide, a fact that is not widely known in the United Kingdom. It is a small RNA virus that has various genotypes, though the most important are HEV 1&2 – the most common types in low-income countries – and HEV 3, which occurs in Europe, the Americas and Australia.

HEV is responsible for about 20 million infections worldwide each year, of which 3 million will be symptomatic and 56,000 lethal. In the United Kingdom, the UK Health Security Agency (UKHSA) follows up confirmed Hepatitis E infections to investigate non-travel related cases of HEV in England and Wales while Public Health Scotland (PHS) monitors HEV infections within their territory.

HEV 1&2 are obligate human pathogens and usually transmitted faecal – orally by contaminated drinking water, while HEV 3 is usually transmitted via inadequately cooked pork, molluscs, or seafood. 90% of pigs in the UK have antibodies to HEV, and around 20% have been known to have an active infection at the time of slaughter. Within Europe the prevalence varies, though there are geographic hotspots with human seroprevalence of >50%. In 2019, UKHSA reported 1202 confirmed HEV infections, PHS reported 158 (>100 cases more than Hepatis A) though due to its often asymptomatic nature, it is reported to be significantly underdiagnosed.

The presentation of acute HEV infections depends on the location of the patient and the genome responsible: In resource poor countries it usually affects young people 15-35 years of age who experience  an acute, self-limiting hepatitis due to HEV1 (Asia) or 2 (Central America). Preterm women are particularly affected, with papers quoting mortality rates of up to 25% and preterm deliveries in 66%. 


This transmission electron micrograph depicts numerous, spheroid-shaped, hepatitis-E viruses (HEV).

This transmission electron micrograph depicts numerous, spheroid-shaped, hepatitis-E viruses (HEV), also known as Orthohepevirus A. Image used with permission from Centers for Disease Control and Prevention (CDC).









In the western world, infections are usually due to HEV3, with only about 5% developing a picture of an acute viral hepatitis. Older men are more affected, and pre-existing liver disease, diabetes or increased alcohol consumption are known risk factors. Incubation period is between 2-8 weeks; malaise, fever, body aches, nausea, and vomiting are characteristic symptoms during the one-week prodromal phase, which is followed by classic icteric symptoms lasting about one week. A small subsection of patients has suffered from HEV-associated neurological injury, such as Guillan-Barré syndrome, neuralgic amyotrophy or encephalitis. A recent review paper by Webb and Dalton suggests testing for Hepatitis E when:

• ALT > 300 IU/L
• Clinical suspicion of drug induced liver injury
• Decompensated chronic liver disease (regardless of LFT results)
• Guillain–Barré syndrome (regardless of LFT results)
• Neuralgic amyotrophy (regardless of LFT results)
• Patients with unexplained acute neurology and a raised ALT 

As most people don’t require treatment, the UKHSA suggests:

During the first 2 weeks of hepatitis E illness:

  • avoid preparing food for others
  • limit contact with others if possible, especially pregnant women, or people with chronic liver disease
Close contacts should:

  • wash hands thoroughly with soap and warm water and then dry properly after contact with an infected person
  • wash hands after going to the toilet, before preparing, serving and eating food

Immunosuppressed patients such as transplant recipients, HIV-positive patients or people receiving chemotherapy for haematological malignancies can develop chronic HEV infections and might get treated with ribavirin.

Pregnant women should contact their obstetric team for advice.

As there is currently no licensed vaccine for Hepatitis E in the United Kingdom, prevention is key. UKHSA suggests:

  • cooking meat and meat products thoroughly
  • avoid eating raw or undercooked meat and shellfish
  • washing hands thoroughly before preparing, serving and eating food.

When travelling to countries with poor sanitation:

  • boil all drinking water, including water for brushing teeth
  • avoid eating raw or undercooked meat and shellfish.

In primary care, a good travel history can be key to diagnose a patient with an unexplained rise in liver function tests and prodromal symptoms.


References:

Aslan, TA; Balaban, HY (2020). Hepatitis E virus: Epidemiology, diagnosis, clinical manifestations, and treatment. World Journal of Gastroenterology. October 7; 26(37): 5543-5560

Horvatits, T; Schulze zur Wisch, J et al. (2019). The clinical perspective on Hepatitis E. Viruses 11, 617

Public Health Scotland: Ten-year gastrointestinal and zoonoses data tables (2023). https://publichealthscotland.scot/publications/ten-year-gastrointestinal-and-zoonoses-data-tables/ten-year-gastrointestinal-and-zoonoses-data-tables-march-2023/ (Accessed 15.08.2023)

UKHSA: Hepatitis E: symptoms, transmission, treatment and prevention (2020). https://www.gov.uk/government/publications/hepatitis-e-symptoms-transmission-prevention-treatment/hepatitis-e-symptoms-transmission-treatment-and-prevention (Accessed 15.08.2023)

Webb, GW; Dalton, HR (2019). Hepatitis E: an underestimated emerging threat. Therapeutic Advances in Infectious Disease Vol. 6: 1–18


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[ Modified: Monday, 4 September 2023, 5:26 PM ]