Comparison of measles antihemolysin test, enzyme-linked immunosorbent assay, and hemagglutination inhibition test with neutralization test for determination of immune status.

Sera were collected from 238 high-school students in Prince Edward Island for the determination of immune status before an anticipated measles outbreak. In addition, history of vaccination status and measles infection was obtained. In the subsequent outbreak, 28 students did contract measles. Specificity for hemagglutination inhibition (HI), antihemolysin (AH), and enzyme-linked immunosorbent assay (ELISA) was 100%, compared with the neutralization test. Corresponding sensitivity values for the tests were 66.0% (HI), 99.5% (AH), and 99.0% (ELISA). Predictive values for susceptibility were 26.9% (HI), 77.8% (AH), 75.7% (ELISA), 80% (neutralization), and 41.4% as determined by history of infection or vaccination. The predictive value for immunity as determined by history of previous infection or vaccination was 91.8%, compared with 100% for the four serological tests. No false-positive results were seen with any of these tests. Compared with the neutralization test, the HI test had 69 false-negative results, the AH had 1, and the ELISA test had 2. The AH and ELISA tests provided sensitive and specific alternatives to the commonly used HI test for immune status determination.