[A study on measles immune status by ELISA].

Both ELISA and HI tests have been used to test 85 paired sera collected shortly before and after a measles epidemic. Results showed that 22 children whose pre-exposure antibody titers were less than 1:2 by HI and less than 1:100 by ELISA contracted measles subsequently and other 2 children, one less than 1:2 by HI and 1:100 by ELISA, one 1:2 by HI and less than 1:100 by ELISA contracted too. 3 of 5 children whose pre-exposure antibody titers ranged from 1:2 to 1:8 by HI and 1:100 to 1:400 by ELISA, contracted the disease and 2 of them developed a subclinical infection. The antibody titers of 56 persons with pre-exposure was 1:16 by HI and greater than or equal to 1:400 by ELISA neither contracted measles nor displayed an antibody enhancement. The comparison between the two tests showed that when the antibody titer of ELISA less than 1:200 was regarded as a negative mark, the sensitivity of this test was 100% and specificity was 95.2%. The ELISA can be used in place of HI test for immune status surveillance against measles.