Immunoassay for the qualitative determination of IgM antibodies against hepatitis A virus (HAV)
Elecsys® Anti-HAV IgM is an immunoassay for the in vitro qualitative determination of IgM antibodies to HAV in human serum and plasma. The assay is used as an aid to detect an acute or recently acquired HAV infection12.
Hepatitis A is an acute, inflammatory liver disease caused by infection with the hepatitis A virus (HAV). HAV is a non-enveloped RNA virus in the family of picornaviruses. Of the 7 known genotypes, 4 can infect humans. Only one serotype of HAV has been documented1-5.
Hepatitis A occurs sporadically and in epidemics worldwide, with around 1.4 million new HAV infections reported each year3,4. HAV is transmitted fecal-orally either by person-to-person contact or ingestion of contaminated food or water in regions of low hygienic standards. Cooked foods can transmit HAV if the temperature during food preparation is inadequate to inactivate the virus or if food is contaminated through infected food handlers1,4-6.
HAV has only been linked with acute hepatitis, and most patients fully recover within two months after infection. Only 10 – 15 % of people infected will have prolonged or relapsed illness for up to 6 months. Anti-HAV IgM becomes detectable 5 – 10 days before onset of symptoms, peaks during the symptomatic period and becomes undetectable in 75 % of patients 3 – 6 months after infection, although anti-HAV IgM can also be detected in some patients for a longer period of time. Anti-HAV IgM antibodies develop only very rarely after vaccination. Assays to detect anti-HAV IgM antibodies are used in the differential diagnosis of acute hepatitis to determine a hepatitis A infection3,7-11.
With this algorithm, all three possible outcomes can be identified by testing first with the anti-HAV (total) assay followed by the anti-HAV IgM assay if necessary. By contrast, an HAV IgG assay alone cannot identify or exclude acute infection; an HAV IgM test is also required.10,13
With this algorithm, all three possible outcomes can be clearly identified by testing first with the anti-HAV IgM assay followed by the anti-HAV (total) assay if necessary.10,13,14
Hepatitis A infection marker profile after natural infection3,7-10,12
Hepatitis A infection: marker profile after natural infection3,7-10,12
* ALT = alanine aminotransferase
* 95 % confidence interval (2-sided)