Comparison of cardiolipin and treponemal tests in the serodiagnosis of yaws.

Results of the Veneral Disease Research Laboratory (VDRL), rapid plasma reagin (RPR), Treponema pallidum haemagglutination (TPHA), T. pallidum immobilisation (TPI), and fluorescent treponemal antibody absorption (FTA-ABS) tests on sera of 661 children from a region where yaws is hypoendemic are compared. For 107 (16.2%) out of 661 sera the FTA-ABS test was the only one showing reactivity; in these instances the test was weakly reactive (intensity of fluorescence scored as +) and the children had no history and no signs or symptoms of treponemal disease. A solitary, weakly reactive FTA-ABS test result seems to have no clinical significance in these cases. The FTA-ABS test can be used as a confirmatory test for yaws instead of the TPI test, if only the results of sera showing an intensity of fluorescence scored as ++ or more are considered to be positive. There appeared to be no significant differences in the results of the VDRL, RPR, and TPHA tests as screening tests for yaws when the TPI or FTA-ABS tests were used as reference tests.     

Comparison of RPR ''teardrop'' card test, VDRL and FTA-ABS tests results on sera from persons with suspected yaws in Columbia.

A small study comparing results of the rapid plasma reagin (RPR) teardrop card test performed in the field, with results of Venereal Disease Research Laboratory (VDRL) and fluorescent treponemal antibody absorption (FTA-ABS) tests performed in the laboratory on venous blood specimens from the same suspected yaws patients was undertaken in Columbia in July 1975. The results suggest that the RPR teardrop card test may be used to screen for infectious, or potentially infectious, yaws patients under field conditions, but that it will not reliably detect patients with VDRL titres of 1:2 or less, or all patients in whom sera are reactive in the FTA-ABS test.     

Comparison of RPR 'teardrop' card test, VDRL and FTA-ABS tests results on sera from persons with suspected yaws in Columbia.

A small study comparing results of the rapid plasma reagin (RPR) teardrop card test performed in the field, with results of Venereal Disease Research Laboratory (VDRL) and fluorescent treponemal antibody absorption (FTA-ABS) tests performed in the laboratory on venous blood specimens from the same suspected yaws patients was undertaken in Columbia in July 1975. The results suggest that the RPR teardrop card test may be used to screen for infectious, or potentially infectious, yaws patients under field conditions, but that it will not reliably detect patients with VDRL titres of 1:2 or less, or all patients in whom sera are reactive in the FTA-ABS test.     

TPHA test. Experience at the Clinic of Dermatology, University of Milan.

The results of serological investigations with the treponemal haemagglutination (TPHA) test are reported in a large number of luetic and non-luetic patients. From these the following conclusions can be drawn: (1) The sensitivity of the TPHA test is decreased if the test is carried out with micromethods; however, in our opinion, the same degree of sensitivity can be obtained either with the macromethod at dilution 1/80-1/60 or with micromethods at 1/20-1/40. (2) The sensitivity of this test is high, being similar to that of the fluorescent treponemal antibody absorption (FTA-ABS) test in primary and secondary syphilis and even higher than that of the FTA-ABS test in treated subjects. (3) The specificity of the reaction is high, as demonstrated by examining sera in patients with a negative history and clinical examination together with negative results to Treponema pallidum immobilisation (TPI) and FTA-ABS tests, and by studying biological false positive sera. (4) For the serological screening, it may be sufficient to perform the TPHA test with the 1/20-1/40 micromethod together with the Venereal Disease Research Laboratory (VDRL) test. In patients with suspected syphilis, it is advisable to perform the TPHA test by the macromethod, in combination with the FTA-ABS test.     

TPHA test. Experience at the Clinic of Dermatology, University of Milan.

The results of serological investigations with the treponemal haemagglutination (TPHA) test are reported in a large number of luetic and non-luetic patients. From these the following conclusions can be drawn: (1) The sensitivity of the TPHA test is decreased if the test is carried out with micromethods; however, in our opinion, the same degree of sensitivity can be obtained either with the macromethod at dilution 1/80-1/60 or with micromethods at 1/20-1/40. (2) The sensitivity of this test is high, being similar to that of the fluorescent treponemal antibody absorption (FTA-ABS) test in primary and secondary syphilis and even higher than that of the FTA-ABS test in treated subjects. (3) The specificity of the reaction is high, as demonstrated by examining sera in patients with a negative history and clinical examination together with negative results to Treponema pallidum immobilisation (TPI) and FTA-ABS tests, and by studying biological false positive sera. (4) For the serological screening, it may be sufficient to perform the TPHA test with the 1/20-1/40 micromethod together with the Venereal Disease Research Laboratory (VDRL) test. In patients with suspected syphilis, it is advisable to perform the TPHA test by the macromethod, in combination with the FTA-ABS test.     

Evaluation of the role of the Treponema pallidum immobilisation test in Britain.

After specimens of sera from 100000 patients had been screened by a reagin and Treponema pallidum haemagglutination assay (TPHA) 2.7% required further examination. The fluorescent treponemal antibody-absorption (FTA-ABS) test confirmed either a negative or positive TPHA result in 95% of the samples, so that no further investigations were required. This accounted for 99% of the specimens submitted to the laboratory. Repeat tests on a further sample resolved many of the remaining discrepancies. Only 0.05% of patients, in whom repeat tests confirmed a positive TPHA but a negative FTA-ABS result, benefited from a TPI test.     

Serological tests for syphilis in Saudi Arabia.

A total of 6684 sera were initially screened for syphilis by the Venereal Disease Research Laboratory (VDRL) test and the Treponema pallidum haemagglutination assay (TPHA). Reactive sera from either or both these tests were tested for confirmation by the fluorescent treponemal antibody-absorbed (FTA-ABS) test. VDRL biological false positive reactors were detected in 0.5% of the total sera examined, with 0.4% and 0.8%, respectively, obtained in pregnant women and blood donors. Eight sera (0.1%) were found to be positive in the TPHA test alone. An overall positivity of 2.7% for syphilis was detected, with a 0.85% positivity in antenatal patients. Infection with T pallidum seemed to be more common in men than in women (1.6:1) and predominated in the age group 20-39 years. Serological testing of sera from 26 mother and infant pairs allowed one case of congenital syphilis to be detected by FTA-ABS (IgM) and identified VDRL biological false positivity in seven infants.     

Syphilis in pregnant women in Mozambique.

To establish the prevalence of syphilis in pregnant women in Mozambique and evaluate present diagnostic methods, 1468 pregnant women in eight of the country's 10 provinces were examined using the Venereal Disease Research Laboratory (VDRL) test. Positive serum samples were also analysed using the Treponema pallidum haemagglutination (TPHA) assay and one group was also analysed using the fluorescent treponemal antibody absorbed (FTA-ABS) test. The prevalence of VDRL seroreactivity was found to be between 4.5% and 14.6%, whereas the prevalence of treponemal disease as verified by TPHA or FTA-ABS tests was between 1.6% and 9.8%. It is concluded that syphilis is relatively common among pregnant women in Mozambique. The predictive value of a positive VDRL test, when adequately performed, was     

Specificity of the FTA-ABS and TPHA tests during pregnancy.

In order to determine whether pregnancy influences the specificity of the fluorescent treponemal antibody absorption (FTA-ABS) and Treponema palidum haemagglutination assay (TPHA) tests, these tests, together with the quantitative fluorescent treponemal antibody (FTA) and Venereal Disease Research Laboratory (VDRL) tests, were carried out simultaneously on 2000 pregnant women who attended for compulsory prenatal screening. In only one patient (0.05% of the total investigated) was a positive result to the TPHA test obtained, the specificity of which it was impossibile to confirm. The FTA-ABS test gave a weakly reactive result of the borderline type but this was found to be non-specific in only four (0.2%) patients. The results of our investigations showed that the specificity of the FTA-ABS and the TPHA tests performed on pregnant women did not differ from the specificity of these tests when carried out on other population groups.     

Specificity of the FTA-ABS and TPHA tests during pregnancy.

In order to determine whether pregnancy influences the specificity of the fluorescent treponemal antibody absorption (FTA-ABS) and Treponema palidum haemagglutination assay (TPHA) tests, these tests, together with the quantitative fluorescent treponemal antibody (FTA) and Venereal Disease Research Laboratory (VDRL) tests, were carried out simultaneously on 2000 pregnant women who attended for compulsory prenatal screening. In only one patient (0.05% of the total investigated) was a positive result to the TPHA test obtained, the specificity of which it was impossibile to confirm. The FTA-ABS test gave a weakly reactive result of the borderline type but this was found to be non-specific in only four (0.2%) patients. The results of our investigations showed that the specificity of the FTA-ABS and the TPHA tests performed on pregnant women did not differ from the specificity of these tests when carried out on other population groups.     

Enzyme linked immunosorbent assays with Treponema pallidum or axial filament of T phagedenis biotype Reiter as antigen: evaluation as screening tests for syphilis.

Enzyme linked immunosorbent assays with an ultrasonicate of Treponema pallidum (TP-ELISA) or axial filament of Treponema phagedenis biotype Reiter (AF-ELISA) were developed to detect treponemal antibody. TP-ELISA and AF-ELISA were compared with the T pallidum haemagglutination assay (TPHA), the fluorescent treponemal antibody-absorbed (FTA-ABS) test, and the Venereal Disease Research Laboratory (VDRL) test for sensitivity and specificity of serodiagnosis of syphilis. A total of 1423 serum samples, 253 from patients with various stages of syphilis, 500 from patients attending a sexually transmitted disease (STD) clinic, and 670 from people without syphilis, were investigated. At all stages of syphilis the sensitivity of the TP-ELISA, the AF-ELISA, the TPHA, and the FTA-ABS test did not differ significantly, except that the AF-ELISA was less sensitive than the TPHA (p less than 0.05) for treated syphilis. In primary syphilis, neurosyphilis, and treated syphilis the TP-ELISA and AF-ELISA were significantly more sensitive than the VDRL test (p less than 0.05). The specificity of all tests was comparable (p greater than 0.05). The TP-ELISA and AF-ELISA appear to be good alternatives to the TPHA as screening tests for syphilis. Because of the easy availability of a well defined antigen the AF-ELISA seems to be better suited for large scale testing.     

Treponema pallidum immune adherence test for serodiagnosis of syphilis. 2: Comparison with glass plate, TPHA, and FTA-ABS tests.

Using sera from 340 patients with syphilis the Treponema pallidum immune adherence (TPIA) test was compared with the glass plate, T. pallidum haemagglutination (TPHA), and fluorescent treponemal antibody-absorbed (FTA-ABS) tests. The results of the TPIA test agreed with those of the glass plate, TPHA, and FTA-ABS tests in 65%, 82%, and 73% of cases respectively. In the quantitative TPIA test no significant correlation with the other tests was observed, and it is, therefore, concluded that the TPIA test has highly individual characteristics. From gel filtration the particular feature of the test was its high sensitivity to the IgM antibody. The TPIA test thus appears to be suitable for estimating antibody in the early stages of the disease.     

Screening for treponemal infection by a new enzyme immunoassay.

A new enzyme immunoassay (EIA, Captia Syphilis-G) for detecting IgG antibodies against Treponema pallidum was evaluated as a screening test for syphilis. When serum samples were tested at a dilution of 1 in 20 (EIA20), the overall agreement between the IgG EIA and serological status based on the T pallidum haemagglutination assay (TPHA) and the fluorescent treponemal antibody absorption (FTA-ABS) test was 99.2% (1310/1321). The sensitivity of the EIA20 was 98.4% (60/61) and the specificity 99.3% (1251/1260). Discrimination between patients with and without treponemal infection was good: the mean EIA20 absorbance ratios (patient/mean low titre positive control results) were 0.49 for antibody negative patients, 3.30 for patients with positive Venereal Diseases Research Laboratory (VDRL) test and TPHA results, and 1.77 for patients with negative VDRL but positive TPHA results. The cut off point for excluding treponemal infection was taken as 0.9. Specimens with ratios of more than 0.9 should be confirmed by the FTA-ABS test and evaluated for specific IgM antibodies to treponemes. When serum samples were tested at a 1 in 50 dilution (EIA50) the sensitivity was lower (80.3%) but the specificity was absolute. The reduction in sensitivity correlated with low absorbance ratios in the patients who were VDRL negative and TPHA positive. The screening performance of the IgG EIA20 is thus comparable with that provided by a combination of the VDRL test and TPHA. The potential for automation makes the EIA an attractive alternative, particularly in larger centres. Alternatively, the test can be performed at a 1 in 50 dilution (EIA50), at which level it is ideally suited for confirming the treponemal status of antibodies in serum samples preselected by positive cardiolipin antigen screening test results.     

Treponema pallidum immune adherence test for serodiagnosis of syphilis. 2: Comparison with glass plate, TPHA, and FTA-ABS tests.

Using sera from 340 patients with syphilis the Treponema pallidum immune adherence (TPIA) test was compared with the glass plate, T. pallidum haemagglutination (TPHA), and fluorescent treponemal antibody-absorbed (FTA-ABS) tests. The results of the TPIA test agreed with those of the glass plate, TPHA, and FTA-ABS tests in 65%, 82%, and 73% of cases respectively. In the quantitative TPIA test no significant correlation with the other tests was observed, and it is, therefore, concluded that the TPIA test has highly individual characteristics. From gel filtration the particular feature of the test was its high sensitivity to the IgM antibody. The TPIA test thus appears to be suitable for estimating antibody in the early stages of the disease.     

Recent observations on the serology of syphilis.

Routine screening of 404 742 sera by the automated micro-haemagglutination assay (AMHA-TP) and the Venereal Disease Research Laboratory (VDRL) test showed that 9848 specimens gave a reactive result to one of the three assays. Reactive results were confirmed by the fluorescent treponemal antibody absorption (FTA-ABS) test. The possibility of false-positive results varied from 0.04-0.38% of all specimens or from 1.7-15.7% of reactive sera. The VDRL test failed to detect reactivity in 56.54% of sera from patients who had previously been infected with Treponema pallidum. The importance of routine testing by the AMHA-TP is illustrated by the detection of four patients with mesaortitis and two with active neurosyphilis among a selected group of 54 patients who had non-reactive results to the VDRL test. Testing of cerebrospinal fluid specimens by the AMHA-TP test produced more specific results than by the other two tests.     

Specificity of the Treponema pallidum haemagglutination test. Analysis of results.

The automated haemagglutination assay using Treponema pallidum antigen (AMHA-TP) and the Venereal Disease Research Laboratory (VDRL) test were used to examine 330 163 sera. Reactive results were checked by the fluorescent treponemal antibody-absorption (FTA-ABS) test. When isolated reactivity or non-reactivity in the AMHA-TP test was investigated an estimated margin of error of 0.7% probably wrongly non-reactive and 0.008% presumably false non-reactive results were found. These figures were confirmed by randomised FTA-ABS tests on 504 sera with repeat AMHA-TP tests. The latter is therefore still the most reliable and practicable method for mass screening for syphilis.     

SLE合并潜伏梅毒1例

患者女,24岁。反复发热、高血压1年余,乏力、浮肿1月。确诊为系统性红斑狼疮(SLE);先后查梅素螺旋体颗粒凝集试验(TPPA)、梅素螺旋体血凝试验(TPHA)以及荧光梅素螺旋体抗体吸收试验(FTA-ABS)均(+),快速血浆反应素环状卡片试验(RPR)1:32。诊断:SLE,潜伏梅毒。经强的松、磷酰胺等治疗后SLE病情显著缓解。先后经苄星青霉素、罗红霉素治疗后,RPR滴度稳步下降。     

Treponemal serology on Bali Island, Indonesia

As part of a multidisciplinary study of the population of Bali, Indonesia, treponemal serology was carried out on 2452 serum samples from subjects of both sexes. Sera reactive to the Treponema pallidum immobilisation test (TPI) were found in 81 (3.3%) subjects with a male prevalence of 4% and a female prevalence of 2%. All the reactive sera were from villagers. Of 1118 students sampled in various towns, none had reactive TPI tests. The prevalence of reactive sera varied greatly from one village to another; up to 50% of the sera examined were reactive. Geographical and socioeconomic analyses of the data show a strict correlation between poor socioeconomic status and high reactivity rates to the TPI test. Fifty-seven per cent of all the reactive sera originated from subjects living in two districts where yaws had recently been reported. Only three of the 1406 subjects, aged 15-29 years, had reactive sera. The reactivity rate steadily increased in the age groups 30-44, 45-59, and 60 years and over. Biological false-positive reactions occurred in 3.8% of the sera tested.     

Treponemal serology on Bali Island, Indonesia.

As part of a multidisciplinary study of the population of Bali, Indonesia, treponemal serology was carried out on 2452 serum samples from subjects of both sexes. Sera reactive to the Treponema pallidum immobilisation test (TPI) were found in 81 (3.3%) subjects with a male prevalence of 4% and a female prevalence of 2%. All the reactive sera were from villagers. Of 1118 students sampled in various towns, none had reactive TPI tests. The prevalence of reactive sera varied greatly from one village to another; up to 50% of the sera examined were reactive. Geographical and socioeconomic analyses of the data show a strict correlation between poor socioeconomic status and high reactivity rates to the TPI test. Fifty-seven per cent of all the reactive sera originated from subjects living in two districts where yaws had recently been reported. Only three of the 1406 subjects, aged 15-29 years, had reactive sera. The reactivity rate steadily increased in the age groups 30-44, 45-59, and 60 years and over. Biological false-positive reactions occurred in 3.8% of the sera tested.     

评价螺旋体乳胶快速反应实验检测梅毒血清的特异性和敏感性

梅毒的诊断依靠临床及实验室检查。目前实验室常规进行快速血浆反应素环状卡片试验(RPR),是一种筛查试验;用死的或活的梅毒螺旋体来检测抗梅毒螺旋体抗体,包括荧光密螺旋体抗体吸收试验(FTA-ABS)和梅毒螺旋体血球凝集试验(TPHA),这两者是确诊试验。除极早期梅毒外,各期梅毒均能得到诊断。心拟脂试验(如RPR)可检测到感染3～5周后的抗体,敏感性高,但缺乏特异性,可导致假阳性结果(如自身免疫性疾病等)。螺旋体试验(FTA-ABS,TPHA)敏感