A reappraisal of the value of the IgM fluorescent treponemal antibody absorption test in the diagnosis of congenital syphilis.

To re-evaluate the usefulness of the IgM fluorescent treponemal antibody absorption test in the diagnosis of congenital syphilis, three groups of infants were investigated. Group 1 infants showed that the test was always negative in normal neonates born to seronegative mothers. From Group 2 infants we determined the standardization of the test using commercially prepared conjugate to allow the maximum exclusion of false positive and negative results. Studies on Group 3 neonates confirmed that the standardized test was extremely successful in determining whether or not an asymptomatic infant was infected with Treponema pallidum. Finally it was shown that the standardization of the test varies with different commercially prepared conjugates. From the investigation it was concluded that the IgM FTA test, if suitably standardized, was a highly successful method for diagnosing congenital syphilis, especially in asymptomatic neonates.