Microbiology: An Evaluation of Two Hemagglutination Tests as Alternatives to F TA-ABS in Otologic Syphilis

Abstract

The microhemagglutination Treponema pallidum test (MHA-TP, Ames Co, El-kart, Ind) and hemagglutination test for syphilis (HATTS, Difco Lab, Detroit, Mich) were evaluated as alternative procedures to the fluorescent treponemal antibody absorption (FTA-ABS) test for screening an older population with suspected otologic syphilis. Both hemagglutination tests are performed in microtiter plates; MHA-TP uses four hours for reaction of serum with Treponema pallidum (TP)-coated sheep erythrocytes, while HATTS takes only one hour using TP-sensitized turkey erythrocytes. Of 267 patients tested using MHA-TP and FTA-ABS, there were 78 presumptively positive for syphilis and 189 presumptively negative. The sensitivity and specificity were93.6%(73/78)and99%(187/189), respectively, for MHA-TP and 100% (78/78) and97.4% (184/189), respectively, for FTA-ABS. Of 103 patients tested with HATTS and FTA-ABS, 13 were positive and 90 were negative. The sensitivities of both HATTS and FT A-ABS were 100% (13/13); the specificities were 97.8% (88/90) and 93.3% (84/90), respectively. These results suggest that either MHA-TP or HATTS can be used to screen for otologic syphilis.