Comparison of serodiagnosis of group B coxsackievirus infections by an immunoglobulin M capture enzyme immunoassay versus microneutralization.

A solid-phase enzyme immunoassay (EIA) with the capture antibody principle was developed and evaluated for detection of immunoglobulin M (IgM) specific for group B coxsackieviruses (CBV) in human serum. Of 19 patients who were culture positive for CBV type 4 infections, the EIA for CBV type 4 IgM was more sensitive (84%; 16/19 positive) than a standard microneutralization test (16%; 3/19 positive) and a microneutralization assay on the IgM fractions obtained by sucrose density gradient fractionation of human serum (68%; 13/19 positive). The attempt to produce a serotype-specific EIA was not successful, as IgM antibodies were detected to heterotypic CBV. The pooled CBV types 2 to 5 IgM EIA demonstrated an overall sensitivity of 88% (21/24 positive) in comparison to virus isolation for CBV types 4 and 5. The EIA was specific for IgM to CBV, with the exception of some cross-reactions with hepatitis A IgM-positive sera (15%; 3/20). In comparison to the microneutralization test, the EIA for pooled CBV IgM was more rapid, less cumbersome, and more sensitive. Commercially available reagents used in this study enable the CBV IgM EIA to be developed in diagnostic virology laboratories.