The use of an immunoenzymatic assay for the estimation of tetanus antitoxin in human sera: a comparison with seroneutralization and indirect haemagglutination.

The ability of an enzyme-linked immunosorbent assay (ELISA) to detect tetanus antitoxin in human sera has been evaluated in comparison with the in vivo seroneutralization test. The results of this study, carried out on 171 serum samples, show that ELISA is a sensitive and specific in vitro test for immunity to tetanus in man; it reveals the minimum protective level of 0.01 IU/ml and is well correlated with seroneutralization. A comparison has also been made with indirect haemagglutination. Differences in specificity in low titered sera, although not statistically significant, have been observed. Reported data suggest that the ELISA may be used for the estimation of tetanus antitoxin in sero-epidemiological surveys and for clinical purposes with reliability equal--and perhaps superior--to that of IHA.