Immunoassay for the qualitative detection of total antibodies against hepatitis A virus (HAV)
Elecsys® Anti-HAV II is an immunoassay for the in vitro qualitative detection of total (IgM and IgG) antibodies to HAV in human serum and plasma. It is used as an aid to detect a past or existing HAV infection or to determine the presence of antibody response to HAV in vaccine recipients.12
Hepatitis A is an acute, inflammatory liver disease caused by infection with HAV. HAV is a non-enveloped RNA virus in the family of Picornaviridae (genus Hepatovirus). Three genotypes and 6 subgenotypes of human HAV have been described based on the variability of the capsid gene. However, only one single serotype of the human HAV has been identified.1-5
Hepatitis A occurs sporadically and in epidemics worldwide, with around 1.5 million new clinically recognized HAV infections.3,4 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 handlers.1,4-6
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. Exposure to HAV creates lifelong immunity against future infection. HAV vaccines are available, which also stimulate active, lifelong immunity with 95 – 100 % efficiency.1-4
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. Anti-HAV IgG, which appears after IgM, begins to rise at or right before the onset of clinical illness, peaks during the convalescent period, and persists to provide lifelong protection against the disease.3,7-11
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 anti-HAV IgG assay alone cannot identify or exclude acute infection; an anti-HAV IgM test is also required.10,14
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.10,14,15
Hepatitis A infection marker profile after natural infection3,7-10,13
References
* 95 % confidence interval (2-sided)
