Importance of the cutoff ratio for detecting antibodies against hepatitis A virus in oral fluids by enzyme immunoassay.

Multiple studies have examined the use of oral fluids in modified serum-based assays aiming to replace serum in antibody detection for hepatitis A. However, the reliable detection of HAV immunity in oral fluid requires an extremely sensitive assay; most immunoassays designed for serum antibody determination lack sufficient sensitivity for this purpose. Consequently, an "in-house" competitive enzyme immunoassay (EIA) designed specifically for use with oral samples collected using a ChemBio(®) device was developed to detect total anti-HAV antibodies (IgG and IgM).