Determination of varicella-zoster virus (VZV) immune status with the VIDAS VZV immunoglobulin G automated immunoassay and the VZVScan latex agglutination assay.

The VIDAS varicella-zoster virus (VZV) immunoglobulin G immunoassay and the VZVScan latex agglutination (LA) test were compared for the detection of VZV antibody in patient sera. Of 625 samples tested, 554 were positive for VZV antibody by one or both methods. Five hundred thirteen (82.1%) samples were positive by both methods, 71 (11.4%) were negative by both methods, and there were 41 (6.6%) discrepant samples. Statistically significant differences in sensitivity and specificity were not found (P = 0.37); however, several observations were made. All 23 VIDAS repeat equivocal samples were LA positive. Fifty-four samples showed prozone effects with the LA assay, all of which resolved as positive.