Comparison of two different enzyme immunoassays for detection of immunoglobulin M antibodies against tick-borne encephalitis virus in serum and cerebrospinal fluid.

Two enzyme immunoassays for the detection in immunoglobulin M (IgM) antibodies against tick-borne encephalitis virus were compared, employing a solid phase coated either with antigen or with mu-chain-specific antiserum to human IgM. The latter IgM-capturing assay system proved to be more sensitive, and its superiority was especially prominent when high titers of tick-borne encephalitis virus-specific IgG antibodies in addition to specific IgM antibodies were present in the sample. The application of this test is a valuable extension of the diagnostic tools for the rapid diagnosis of tick-borne encephalitis by IgM detection. Since specific IgG does not interfere, diagnosis can be readily established when patients have already developed high titers of IgG antibodies relatively late after the onset of the disease.