Screening, diagnosis and risks associated with Hepatitis E virus infection

ABSTRACT

Introduction: Hepatitis E virus (HEV) is the main cause of hepatitis worldwide. Our knowledge of this single-strand positive-sense RNA virus, discovered in the 1980s, has improved greatly in recent years.

Areas covered: We review the most recent information on diagnostic tools, including serological and molecular assays, the recommended diagnostic algorithm, and the clinical manifestations of HEV infections.

Expert opinion: The performance of serological and molecular assays has improved greatly in recent years and the availability of a WHO standard has been invaluable for comparing the performance of molecular assays. The more efficient serological and molecular assays have led to a clearer picture of HEV epidemiology. It is now established that HEV is distributed worldwide. The European Association for the Study of the Liver (EASL) now recommends testing for anti-HEV IgM and HEV RNA. Molecular tests indicate that HEV RNA is very common in asymptomatic blood donors. The description of transfusion-transmitted HEV makes having optimal strategies essential for improving blood safety. Like other hepatitis viruses, HEV infection must be suspected whenever a patient presents with clinical or biochemical features of hepatitis. An HEV infection can also have extra-hepatic manifestations, especially neurological and renal disorders.

KEYWORDS:

• Hepatitis E virus
• serological test
• molecular diagnosis
• diagnosis algorithm
• neurological manifestations
• renal manifestations

Article highlights

• As the performance of anti-HEV IgM assays vary, comparative studies using the most recent versions of assays and reference materials must be performed.

• Detection of anti-HEV IgG is useful for epidemiological studies; the analytical sensitivity of anti-HEV IgG assays must be determined using the WHO standard and taken into account for interpreting seroprevalence data.

• How long does immunity against HEV last?

• The performance of assays detecting HEV RNA must be assessed using the WHO reference panel.

• It is essential to detect HEV RNA in the blood and faeces of immunocompromised patients for diagnosis of chronic infections and monitoring therapy.

• Studies on HEV diversity and animal strains that may be transmitted to humans are needed. Molecular tools for detecting all human pathogenic strains must be implemented.

• Studies on HEV antigen in both immunocompetent and immunocompromised patients are needed in order to confirm its diagnostic relevance.

• Neurological manifestations of HEV infections are now well recognized. Patients with unexplained neurological manifestations, even though they have no or minimal changes in liver function, should be tested for HEV.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Revivewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.