Detection of antibodies of Treponema pallidumin hospitalized patients

OBJECTIVE To investigate the age distribution of the positive cases screened by syphilis enzyme-linked immunosorbent assay(TP-ELISA),and evaluate Treponema pallidum ELISA and gelatin particle agglutination test(TPPA) in the detection of syphilis.METHODS The preliminary screening of positive cases was conducted with syphilis antibody ELISA for the inpatients.The further confirmation of TPPA method was conducted for the cases whose double-check results remained positive.The ELISA-positive cases were divided into the gray-area group and positive group according to S/CO values,and the two groups were statistically compared with those of TPPA analysis respectively.RESULTS Totally 113 positive cases were found using ELISA method.Among them,93.81% of cases could also be screened with TPPA analysis;the positive rate was 5.00% for the case group of over sixty-year old inpatients which accounted for 46.90% of total positive cases.No statistical difference could be found between ELISA-positive cases and TPPA-positive cases in both gray-area group and positive group according to S/CO values.CONCLUSION False-positive cases exist in the syphilis serology tests,especially among the very old people.When the result of ELISA test is inconsistent with the medical history and clinical manifestation of the patients,re-examination and confirmation by TPPA test should be carried out as soon as possible,meanwhile,regular follow-up is needed.