Introduction of routine testing for Hepatitis E Virus (HEV) in the serological investigation of acute hepatitis

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The NVRL has introduced routine testing for Hepatitis E virus (HEV) as part of the panel of tests performed for the serological investigation of acute hepatitis. All serum samples tested for Hepatitis A virus (HAV) IgM will automatically be tested for Hepatitis E virus. In addition, samples yielding positive HEV IgM results will be tested by HEV RNA polymerase chain reaction (PCR).

Rationale for this change in testing policy

Our understanding of the epidemiology of HEV has changed significantly over the past number of years. Once thought to be an infection associated with travel to the developing world, it is now known that non travel-associated HEV cases are common in Europe and likely to be zoonotic in origin. In the UK, HEV is acknowledged as a more common infection than HAV with significant increases in the number of non travel-associated HEV cases being reported in recent years. HEV is not yet a notifiable disease in Ireland: however, so far this year the NVRL has confirmed four cases of autochthonous HEV infection. Previously, testing for Hepatitis E virus was performed by the NVRL only when specifically requested and requests for HEV numbered far less than those for HAV IgM. It is therefore likely that a number of patients presenting with acute hepatitis had HEV infection which was not diagnosed on laboratory investigation.

Clinical Features of Hepatitis E Virus

The incubation period for HEV is 2-8 weeks (average 40 days) and the majority of infections are asymptomatic. In symptomatic cases, the disease is usually mild and self-limiting; however, chronic HEV infection can be seen in immunocompromised individuals, including solid organ transplant recipients, oncology/haematology patients, or those with HIV-infection. Of note, these patients may also be asymptomatic with only mildly deranged liver enzymes. In most cases no treatment for HEV is required as the illness is self-limiting. There is currently no vaccine available for HEV: however, secondary person-to-person transmission is rare with appropriate hygiene precautions.

Further Information

If you would like to discuss this change in policy or require any further information please contact the NVRL 01 7161223