Addressing unmet needs in the diagnosis of hepatitis E virus (HEV) infection

There are four main genotypes of HEV that can infect humans: Genotypes 1 and 2 are common in developing countries and are transmitted fecal-orally by contaminated water and food. On the other hand, Genotypes 3 and 4 are common in developed countries and can occasionally transmit to humans zoonotically through close contact with infected animals or consumption of contaminated animal products. While most individuals with HEV infection do not exhibit symptoms and typically experience spontaneous viral clearance without treatment, HEV infection can lead to severe hepatitis with liver failure and death in patients with certain risk factors (e.g. underlying chronic liver disease, pregnancy). In immunocompromised individuals, the infection can become chronic, leading to cirrhosis. Both acute and chronic HEV infections can manifest extrahepatically.

As a result of a still-evolving landscape of diagnostic tools, inadequate physician awareness, and incomplete implementation of clinical testing guidelines, the global burden of HEV infection is likely severely underestimate. For similar reasons, individuals presenting with hepatitis may be misdiagnosed.

The European Association for the Study of the Liver (EASL) recommends testing for HEV infection for all individuals with symptoms of acute hepatitis, unexplained flares of chronic liver disease, decompensated chronic liver disease, immunosuppressed patients with abnormal liver enzyme, with certain neurological symptoms, and when drug-induced liver injury (DILI) is suspected. Various methodologies (nucleic acid amplification techniques and/or immunoassays) can be used to diagnose an HEV infection in immunocompetent patients; if only serological testing is used it relies on the combined detection of anti-HEV IgM and rising anti-HEV IgG titers.

Read the White Paper "Diagnosis of Hepatitis E Virus Infection: Current Capabilities and Shortcomings" and view the accompanying infographic ‘Hepatitis E Virus (HEV) Infection’ to learn more about HEV virology and epidemiology, the available approaches for diagnosis of HEV infection, and possible areas for improvement in the diagnosis of HEV infection:

The new Elecsys Anti-HEV IgM and Anti-HEV IgG immunoassays have been designed for the highly sensitive and specific detection of HEV infection, which in immunocompetent patients can be based on serology testing alone when both assays are used in combination.

The Elecsys Anti-HEV IgM assay is intended for the in vitro qualitative detection of IgM antibodies to HEV in human serum and plasma. Qualitative measurement of IgM antibodies to HEV is used as an aid in the diagnosis of acute or recently acquired HEV infection by detecting anti‑HEV IgM antibodies during acute infection, in combination with the detection of rising titers of IgG antibodies to HEV or HEV RNA and in conjunction with other laboratory results and clinical information, as part of the differential diagnosis of acute hepatitis to enable timely initiation of medical interventions.

The Elecsys Anti-HEV IgG assay is intended for the in vitro quantitative determination of IgG antibodies to HEV in human serum and plasma. Quantitative measurement of IgG antibodies to HEV is used as an aid in the diagnosis of acute HEV infection (e.g. by determining rising IgG titers during acute infection, in combination with detection of IgM antibodies to HEV or HEV RNA), as part of the differential diagnosis of acute hepatitis to enable timely initiation of medical interventions; in assessing the immune status to HEV; in estimating the risk of HEV reinfection; or in detecting past HEV infections in seroepidemiological studies.

Both assays are available for use on the cobas® e 411 analyzer, cobas® e 601/602 modules, and cobas® e 402 (cobas® pure system) and cobas® e 801 (cobas® 8000 and cobas® pro systems) analytical units.