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Diseases / Hepatitis E

Hepatitis E

What is it?: 

Hepatitis E virus (HEV) is a leading cause of acute viral hepatitis in developing countries. A global burden of disease study estimated that HEV genotypes 1 and 2 account for approximately 20.1 million HEV infections, 3.4 million symptomatic cases, 70 000 deaths, and 3000 stillbirths annually.

The epidemiology and clinical presentation of HEV infection vary greatly by geographic location, based primarily on differences in circulating HEV genotypes. Hepatitis E occurring sporadically or as disease outbreaks has been identified in at least 63 countries, of which about half have reported large outbreaks. There are also countries with no recorded sporadic disease or outbreak but where serologic evidence of past HEV infection has been reported, suggesting that HEV infection may be endemic.1

Clinical features: 

Clinical features of acute hepatitis E are similar to those of other types of viral hepatitis. Typical signs and symptoms of hepatitis E include:

  • an initial phase of fever, reduced appetite, nausea and vomiting, lasting for a few days;
  • abdominal pain, itching, skin rash, or joint pain;
  • jaundice (yellow discolouration of the skin and sclera of the eyes), with dark urine and pale stools;
  • a slightly enlarged, tender liver (hepatomegaly).

These symptoms are largely indistinguishable from those experienced during any acute phase of hepatic illness and typically last for 1 - 6 weeks.

In rare cases, acute hepatitis E can result in fulminant hepatitis (acute liver failure) and death. Fulminant hepatitis occurs more frequently when hepatitis E occurs during pregnancy. Pregnant women with hepatitis E are at an increased risk of acute liver failure, fetal loss and mortality. Case fatality rates as high as 20 - 25 % have been reported among pregnant women in their third trimester.2

Mode of transmission: 

HEV is transmitted mainly through the faecal-oral route due to faecal contamination of drinking water. Other transmission routes have been identified, which include:

  • foodborne transmission from ingestion of undercooked meat or meat products derived from infected animals (HEV has also been detected in pig livers);
  • transfusion of infected blood products;
  • vertical transmission from a pregnant woman to her foetus.

The infected persons are believed to excrete the virus beginning a few days before to around 3 - 4 weeks after the onset of disease.2

Incubation period: 

The incubation period following exposure to HEV ranges from 2 - 10 weeks, with a mean of 5 - 6 weeks.2

Prevention: 

Adopt Food Safety to prevent foodborne diseases at individual level: 2

  1. Maintain hygienic practices such as hand washing with safe water, particularly before handling food or eating, and after using the toilet or handling vomitus or faecal matter.
  2. Obtain drinking water from the mains and boil it before consumption. Avoid consumption of water and ice of unknown purity.
  3. Purchase fresh food from reliable sources. Do not patronise illegal hawkers.
  4. Clean and wash food thoroughly.
  5. Avoid raw food or undercooked food.
  6. Use separate chopsticks for handling raw food and cooked food when having hotpot.
Managment: 

There is no specific treatment capable of altering the course of acute hepatitis E. Prevention is the most effective approach against the disease. As hepatitis E is usually self-limiting, hospitalisation is generally not required. However, hospitalisation is required for people with fulminant hepatitis and should also be considered for symptomatic pregnant women.2

Reference:

  1. World Health Organization. Weekly epidemiological record. Hepatitis E vaccine: WHO position paper - May 2015. 2015;18(90):185-200.
  2. Centre for Health Protection. Communicable diseases – Hepatitis E. 5 July 2019. [ONLINE] https://www.chp.gov.hk/en/healthtopics/content/24/12257.html Accessed on 29 Mar 2021.

 

MAT-HK-2100420-1.0-04/2021