Hepatitis E

Hepatitis E virus (HEV) infection affects millions of people globally. It is most prevalent in Africa and Asia, and is increasing in parts of Europe but declining in the US.

Transmission is through the faecal-oral route in the developing world and through locally acquired zoonotic infection in the developed world.

Approximately 95% of patients with acute HEV infection have asymptomatic infection. If symptoms do occur, they are non-specific and may include fatigue, anorexia, and nausea; if the patient develops jaundice, they may also present with pruritus.

Diagnosis is made by detection of anti-HEV immunoglobulin M (anti-HEV IgM) and confirmed with HEV RNA testing in serum or stool. Note that HEV RNA may be the only positive test in immunosuppressed patients.

Acute HEV infection is self-limiting in the vast majority of patients. Pregnant women and patients with underlying chronic liver disease are at particular risk for acute liver failure. Immunosuppressed patients may fail to clear the infection and are at risk for progressing to chronic hepatitis.

Treatment for acute HEV infection is supportive in the majority of cases. Severe infection may require treatment with antiviral therapy to prevent progression to acute liver failure. Treatment options for chronic HEV infection include reduction of immunosuppression if appropriate to do so, ribavirin, and peginterferon alfa.

Hepatitis E is an infection of the liver caused by the hepatitis E virus (HEV).[1]World Health Organization. Waterbone outbreaks of hepatitis E: recognition, investigation and control: technical report. Jul 2014 [internet publication]. https://www.who.int/publications/i/item/9789241507608 ​ HEV infection, although the most common cause of acute viral hepatitis globally, results in asymptomatic infection in the majority (possibly over 95%) of affected people.[2]European Association for the Study of the Liver. EASL clinical practice guidelines on hepatitis E virus infection. J Hepatol. 2018 Jun;68(6):1256-71. https://www.journal-of-hepatology.eu/article/S0168-8278(18)30155-7/fulltext http://www.ncbi.nlm.nih.gov/pubmed/29609832?tool=bestpractice.com [3]Lhomme S, Marion O, Abravanel F, et al. Clinical manifestations, pathogenesis and treatment of hepatitis E virus infections. J Clin Med. 2020 Jan 24;9(2):331. https://www.mdpi.com/2077-0383/9/2/331 http://www.ncbi.nlm.nih.gov/pubmed/31991629?tool=bestpractice.com ​​​​ If symptomatic infection does occur, it usually causes an acute self-limiting illness that is typically indistinguishable from other forms of acute viral hepatitis. However, rarely, acute liver failure can occur (pregnant women are particularly at risk). Chronic HEV infection (which has been defined as a persistence of HEV replication for 3 or more months) is almost exclusively limited to immunosuppressed patients.[2]European Association for the Study of the Liver. EASL clinical practice guidelines on hepatitis E virus infection. J Hepatol. 2018 Jun;68(6):1256-71. https://www.journal-of-hepatology.eu/article/S0168-8278(18)30155-7/fulltext http://www.ncbi.nlm.nih.gov/pubmed/29609832?tool=bestpractice.com [4]Kamar N, Selves J, Mansuy JM, et al. Hepatitis E virus and chronic hepatitis in organ-transplant recipients. N Engl J Med. 2008 Feb 21;358(8):811-7. https://www.nejm.org/doi/full/10.1056/NEJMoa0706992 http://www.ncbi.nlm.nih.gov/pubmed/18287603?tool=bestpractice.com [5]Marion O, Abravanel F, Lhomme S, et al. Hepatitis E in transplantation. Curr Infect Dis Rep. 2016 Mar;18(3):8. http://www.ncbi.nlm.nih.gov/pubmed/26838163?tool=bestpractice.com ​​​​

HEV is an RNA virus that has historically been transmitted primarily via the faecal-oral route.[1]World Health Organization. Waterbone outbreaks of hepatitis E: recognition, investigation and control: technical report. Jul 2014 [internet publication]. https://www.who.int/publications/i/item/9789241507608 ​ The improvement in living conditions in many parts of the world and migration patterns have changed the main route of transmission from faecal-oral to zoonotic in these areas, leading to food-borne cases of infection.​

This topic covers HEV in adults.