Adaptation of a commercially available indirect fluorescent antibody slide test for measuring measles-specific immunoglobulins

A commercially available indirect fluorescent antibody (IFA) test was evaluated for the determination of measles-specific immunoglobulins G and M (MIgG, MIgM). The IFA test detected fourfold rises of MIgG in 34 of 35 (97%) cases of measles confirmed by complement fixation or hemagglutination inhibition. In determining immune status, MIgG-IFA correlated with hemagglutination inhibition in 22 of 23 (96%) cases. The IFA test detected MIgM in only 11 of 34 acute-phase sera collected within 5 days of the reported onset of rash and in the convalescent specimens of another 13 of the 35 specimens. The IFA test is an effective method for the conventional diagnosis of measles and for determining immune status. This IFA test has a limited role as a rapid diagnostic test for measles when used to detect measles-specific MIgM in acute-phase sera obtained from patients with suspected measles.