Infection: Hepatitis E virus (HEV) infection
Brief description:
- Virus that causes an acute hepatitis that self resolves
- Majority of infections are asymptomatic.
- Previously thought to only be acquired overseas, however 8-10% of NZ blood donors have serological evidence of infection.
- Can cause chronic infection in people with significant immunosuppression (e.g. liver transplantation)
Did you know?
- Hepatitis E is transmitted by the faecal-oral route.
- Genotypes 1 and 2 cause infection in humans only and are endemic in Asia and Africa
- Genotypes 3 and 4 are zoonotic and are present in Europe, USA and Asia. Infection is usually transmitted by consumption of undercooked meat such as pork. 90% of NZ pigs show serological evidence of infection.
Who should I test?
Testing generally reserved for patients with acute hepatitis (ALT > 500) with history of travel to endemic regions or with no alternative diagnosis.
- Mimics to consider in patients with hepatitis: hepatitis A, B and C, HIV, syphilis
- In an outbreak setting a lower threshold for testing is usually warranted
Test of choice:
Request Hep E serology
Hepatitis E virus serology – IgM and IgG
- Anti-HEV IgM is usually detectable 2-3 weeks after exposure and is usually negative after 3-6 months. Therefore detection is consistent with acute infection.
- Anti-HEV IgG is detectable early in the illness and is long lasting. Detection is usually consistent with prior infection if the IgM is negative.
Tests to avoid/specialist tests:
- Used to diagnose chronic HEV infection in immunosuppressed patients