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Objective: This study retrospectively compared false-positive result frequencies of 3 syphilis serology screening tests and assessed whether false positivity was associated with pregnancy and age., Methods: Results for 3 screening tests were retrieved from the laboratory database, including rapid plasma reagin (RPR) assay between October 2016 and September 2019, BioPlex 2200 Syphilis Total immunoassay between May 2020 and January 2022, and Alinity i Syphilis TP assay between February 2022 and April 2023. The false-positive result frequencies were calculated based on testing algorithm criteria., Results: False-positive result frequency for BioPlex was 0.61% (90/14,707), significantly higher than 0.29% (50/17,447) for RPR and 0.38% (55/14,631) for Alinity (both P < .01). Patients with false-positive results were significantly older than patients with nonreactive results for RPR (median age: 36 vs 28, P < .001), but not for BioPlex or Alinity. For all 3 tests, the positive predictive values in pregnant women were lower than those in nonpregnant women or men. However, pregnant women did not exhibit a higher false-positive result frequency., Conclusion: Although false-positive result frequencies were low overall for all 3 syphilis serology tests, there is a significant difference between different tests. Pregnancy was not associated with more false-positive results for all 3 tests., (© The Author(s) 2023. Published by Oxford University Press on behalf of American Society for Clinical Pathology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

There are a variety of nontreponemal test (NTT) and treponemal test (TT) kits for the serologic diagnosis of syphilis. Because of the complexity of the infection (multiple clinical stages) and the different antigens used in these kits, a systematic evaluation of the accuracy of the currently available commercial tests is warranted. Our objective was to evaluate the performance of commercially available tests for the diagnosis of syphilis infection. In this study, we analyzed one NTT (Venereal Disease Research Laboratory [VDRL] test, Wiener Laboratories, Rosario, Argentina) and two TTs (fluorescent treponemal antibody absorption [FTA-ABS] test, Euroimmun, Lübeck, Germany, and syphilis recombinant ELISA v. 4.0 test [ELISA], Wiener Laboratories, Rosario, Argentina) using a panel of 187 samples, including serum samples from 31 individuals with primary syphilis, 77 with secondary syphilis, and 79 with latent syphilis. An additional 192 samples from uninfected individuals and 323 serum samples from individuals with other diseases were included. The sensitivities of the VDRL, ELISA, and FTA-ABS tests were 97.9%, 100%, and 96.3%, respectively. The VDRL and ELISA tests showed a specificity of 100%, and the FTA-ABS test showed a specificity of 99.5%. Accuracy was 98.9% for the VDRL test, 100% for the ELISA, and 97.9% for the FTA-ABS test. For primary, secondary, and latent syphilis, the ELISA achieved a diagnostic performance of 100%, whereas the sensitivity for the VDRL and FTA-ABS tests ranged from 96.8% to 98.7% and 93.7% to 98.7%, respectively. No difference was observed when the tests were used as traditional or reverse algorithms. In general, all three tests are able to discriminate positive and negative samples for syphilis, regardless of the diagnostic algorithm.

Published studies show that >99% of sera reactive in the reverse syphilis testing algorithm (RSTA) screening assay with an index above an assay-specific threshold confirm as reactive, with either a rapid plasma reagin-reactive (RPR R ) or RPR-nonreactive/Treponema pallidum particle agglutination-reactive (TPPA R ) result. However, the relationship between screen indices and confirmatory patterns has not been characterized. We thus assessed confirmatory testing results for 577 sera submitted for RSTA testing and a screen-reactive result in the DiaSorin Liaison assay. The median screen index was significantly higher for RPR R samples than TPPA R samples (55.6 versus 10.4), and the proportion with indices >28.3 (median for all 577 samples) was significantly higher for RPR R versus TPPA R samples (82% versus 26%). However, RPR R titers did not significantly correlate with screen indices (R 2  = 0.02). These findings demonstrate a significant relationship between RSTA screen indices and confirmatory assay results. The clinical utility of this relationship requires further study., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Adenoid hypertrophy (AH) is a common disease in children. We describe two cases of AH in children with syphilis enzyme-linked immunosorbent assay (EIA) for false-positive. To our knowledge, there are few reports of false-positive in syphilis EIA in children with AH. Two cases of AH children with syphilis EIA positive samples were confirmed by TPPA and LIA, both showed negative reaction. Therefore, the occurrence of syphilis EIA positive reactions in such diseases should dramatically arouse the attention of docimasters and doctors so as to avoid misdiagnosis caused by false-positive in children with AH.

To investigate the detection threshold of Treponema pallidum specific antibody method by chemiluminescent immunoassay (CLIA) in Siemens ADVIA Centaur XP for Syphilis serological test, and compare with the results derived from CMIA, TP-WB and TPPA method. The result can serve as reference for the application of CLIA. In total 30 887 samples screened by Treponema pallidum specific antibody method were collected by Abbott architect i2000 CMIA from July 2018 to July 2019 in Yanda Hospital of Hebei Province. We selected 153 patients with the ratio of sample absorbance to critical value (S/CO) of 1-9 by CMIA screening of Treponema pallidum specific antibody as the research objects. The reverse sequence of syphilis serological detection was adopted, and TP-WB and TPPA were used as the confirmation methods respectively. MedCalc software was used to analyze the results of ROC curve, and the cut-off value was obtained. Chi square test was used to test the difference significance of counting data. The detection results of Treponema pallidum specific antibody in the same batch of serum samples were unequal by different methods. There was no significant difference between CLIA method and TPPA method, but significant difference between CLIA method with TP-WB method and CMIA method was found. TPPA test results and TP-WB test results were taken as gold standards, ROC curve analysis showed that the best diagnostic cutoff value of CLIA method was 4.01 and 16.06, respectively, and the area under the curve was 0.961 and 0.838. The suggested cutoff value of CLIA method is quite different when using different syphilis serological test methods as the gold standard, Therefore, when the S/CO value determined by CLIA is between 1.00 to 16.06, TP-WB method should be recommended as the first choice in laboratory serological test for recheck and confirmation to avoid clinical misdiagnosis.

The analytical performance of the FDA-cleared AIX1000 automated RPR testing platform was evaluated in comparison to manual RPR card testing. Eight hundred thirty-three patient serum samples were analyzed, 87 samples were positive by the AIX1000, 108 were positive by the manual test method; overall agreement between methods was 96.5% (κ = 0.83). Cases were further classified by clinical and laboratory-based confirmation of disease, to which reactivity rates were compared, yielding sensitivities of 96.4% and 100%, and specificities of 99.2% and 96.8% for the automated and manual RPR methods, respectively. The difference in specificity between methods was statistically significant (P < 0.001). Twenty-five of 29 samples with discordant results were reactive by manual testing (titers of 1:1 or 1:2); 21 of 25 patients with negative AIX100 results were identified to have histories of remote, treated syphilis. Overall, the AIX1000 platform demonstrated excellent agreement with the manual RPR method; discrepancies occurred with specimens at the threshold of reactivity., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background The rapid plasma reagin (RPR) assay is commonly used as a surrogate marker of infectious syphilis, but is non-specific, slow to change and variable in its rate of decline post treatment., Methods: Within an urban sexual health service testing predominantly men who have sex with men, a file review of RPR changes was undertaken in all subjects who had a dilution level of ≥1:4, between January 2015 to the end of December 2018., Results: Overall, 248 cases of infectious syphilis were identified in 215 subjects (165 HIV seropositive, 50 HIV seronegative). Among unique-subject cases with follow-up RPR recorded, seroreversion to a non-reactive titre was achieved in only 42.3% (71/168) cases at a median of 235 days (interquartile range: 138-348 days) and was significantly less likely if patients had HIV infection (P = 0.02), late latent syphilis (P = 0.003) or a subsequent syphilis infection (P < 0.0001). Having HIV infection (P = 0.03) or a subsequent episode of syphilis (P = 0.01) were associated with a lower likelihood of documented cure., Conclusions: The slow decay in RPR titres post therapy and the inability of a significant number of subjects to achieve a non-reactive result over time makes RPR a poor test for assessing the adequacy of treatment or in diagnosing re-infection, especially in populations having repeated and frequent risk exposures. As the number of syphilis cases continue to climb, better tests that accurately assess pathogen presence are urgently needed.

Discordant syphilis test results, with a reactive nontreponemal test and nonreactive treponemal test are usually considered biological false-positive test results (BFPs), which can be attributed to other conditions. Syphilis surveillance laws mandate laboratory reporting of reactive syphilis tests, which include many BFPs. We describe the frequency of BFPs, titer distributions, and titer increases from reported test results in Florida and New York City (NYC). Reactive nontreponemal tests for individuals with at least one nonreactive treponemal test and no reactive treponemal test were extracted from sexually transmitted disease (STD) surveillance systems in Florida and NYC from 2013 to 2017. Characteristics of individuals with BFPs were analyzed after selecting the observation with the highest titer from each individual. We next considered all results from individuals to characterize persons who had a 4-fold titer increase between successive nontreponemal tests. Among 526,540 reactive nontreponemal tests, there were 57,580 BFPs (11%) from 39,920 individuals. Over 90% ( n  = 52,330) of BFPs were low titer (≤1:4), but 654 (1%) were high-titer BFPs (≥1:32). Very high-titer (≥1:128) BFPs were more common among individuals over 60 years of age (odds ratio [OR], 2.68; 95% confidence interval [CI], 1.22 to 5.91). A 4-fold increase in titer was observed among 1,863 (14%) individuals with more than one reported BFP. Most BFPs detected by surveillance were low titer, but some were high titer and some had a 4-fold increase in titer. Review of patient histories might identify underlying conditions contributing to these high and rising titers., (Copyright © 2019 American Society for Microbiology.)

Background: Dual human immunodeficiency virus (HIV)/syphilis rapid, point-of-care testing may enhance syphilis screening among high-risk populations, increase case finding, reduce time to treatment, and prevent complications. We assessed the laboratory-based performance of a rapid dual HIV/syphilis test using serum collected from patients enrolled in the Zimbabwe Sexually Transmitted Infections (STI) Etiology study., Methods: Blood specimens were collected from patients presenting with STI syndromes in 6, predominantly urban STI clinics in different regions of Zimbabwe. All specimens were tested at a central research laboratory using the Standard Diagnostics Bioline HIV/Syphilis Duo test. The treponemal syphilis component of the dual rapid test was compared with the Treponema pallidum hemagglutination assay (TPHA) as a gold standard comparator, both alone or in combination with a nontreponemal test, the rapid plasma reagin test. The HIV component of the dual test was compared with a combination of HIV rapid tests conducted at the research laboratory following the Zimbabwe national HIV testing algorithm., Results: Of 600 men and women enrolled in the study, 436 consented to serological syphilis and HIV testing and had specimens successfully tested by all assays. The treponemal component of the dual test had a sensitivity of 66.2% (95% confidence interval [CI], 55.2%-77.2%) and a specificity of 96.4% (95% CI, 94.5%-98.3%) when compared with TPHA; the sensitivity increased to 91.7% (95% CI, 82.6%-99.9%) when both TPHA and rapid plasma reagin were positive. The HIV component of the dual test had a sensitivity of 99.4% (95% CI, 98.4%-99.9%) and a specificity of 100% (95% CI, 99.9%-100%) when compared with the HIV testing algorithm., Conclusions: Laboratory performance of the SD Bioline HIV/Syphilis Duo test was high for the HIV component of the test. Sensitivity of the treponemal component was lower than reported from most laboratory-based evaluations in the literature. However, sensitivity of the test increased substantially among patients more likely to have active syphilis for which results of both standard treponemal and nontreponemal tests were positive.

Syphilis rates in much of the world are now at their highest levels in almost three decades, and new approaches to controlling syphilis, including diagnostic tests with shorter window periods, are urgently needed. We compared the sensitivity of syphilis serological testing using the rapid plasma reagin (RPR) test with that of the combination of serological testing and an experimental 23S rRNA Treponema pallidum real-time transcription-mediated amplification (TMA) assay performed on rectal and pharyngeal mucosal swabs. T. pallidum PCR assays for the tpp47 gene were performed on all TMA-positive specimens, as well as specimens from 20 randomly selected TMA-negative men. A total of 545 men who have sex with men (MSM) who were seen in a sexually transmitted disease clinic provided 506 pharyngeal specimens and 410 rectal specimens with valid TMA results. Twenty-two men (4%) were diagnosed with syphilis on the basis of positive RPR test results and clinical diagnoses, including 3 men with primary infections, 8 with secondary syphilis, 9 with early latent syphilis, 1 with late latent syphilis, and 1 with an unstaged infection. Two additional men were diagnosed based on positive rectal mucosal TMA assay results alone, and both also tested positive by PCR assay. At least 1 specimen was TMA positive for 12 of 24 men with syphilis (sensitivity, 50% [95% confidence interval [CI], 29 to 71%]). RPR testing and clinical diagnosis were 92% sensitive (95% CI, 73 to 99%) in identifying infected men. Combining mucosal TMA testing and serological testing may increase the sensitivity of syphilis screening in high-risk populations., (Copyright © 2019 American Society for Microbiology.)

The screening for syphilis during pregnancy is important to prevent intrauterine transmission and complications. Prozone phenomenon may cause a false negative result in non-treponemal syphilis tests, which complicates an accurate diagnosis. In this case report a newborn syphilis case was presented to emphasize the importance of reverse algorithm in diagnosis and the prozone phenomenon which can cause problems in rapid plasma reagin (RPR) test. The 2920 g infant patient was born from a 24-year-old mother with no known diseases, at the 35th week of gestation by cesarean section due to premature rupture of membranes. The initial physical examination of the newborn revealed erythema and exfoliation of the bilateral hands and feet. Laboratory results revealed CRP: 90 mg/L, WBC: 19.2 x 103/µl, hemoglobin: 9.5 g/dl, platelet count: 214 x 103/µl, HIV-Ag/Ab: non-reactive, anti-Toxoplasma gondii IgM and IgG: negative, anti-cytomegalovirus IgM: negative, anti-cytomegalovirus IgG: positive (128.7 AU/ml), anti-Rubella IgM: negative, anti-Rubella IgG: positive (26 IU/ml), anti-Treponema pallidum (anti-T.pallidum) antibody [IgM and IgG by the chemiluminescence microparticle enzyme immunoassay (Architect Syphilis TP; Abbott Japan Co, Japan)]: positive (Signal Cut Off value (S/CO): 28.35), and RPR (Omega Diagnostics, UK): negative. All of the above ELISA tests were performed by using Architect (Abbott Diagnostics, Wiesbaden, Germany) kits. When the RPR test was repeated with serial dilutions of the serum in order to detect prozone phenomenon, positive reaction was detected starting from 1:2 and ending at 1:64 dilution. It was determined that the mother was not tested for syphilis during her pregnancy. When both the mother and the father were tested for syphilis, the mother's anti-T.pallidum total antibody test result was reactive (S/CO: 30.52) and the RPR was positive at 1:32 dilution, while the father's anti-T.pallidum total antibody test result was reactive (S/CO: 16.05) and the RPR was negative. A four-fold difference between the maternal and infant RPR dilutions is required by the guidelines for a laboratory diagnosis of congenital syphilis. Although this criterion was not met in the newborn, the case was accepted as congenital syphilis due to clinical findings. Congenital syphilis must be considered in the differential diagnosis in the presence of skin manifestations at the birth and early neonatal period. Accurate and early diagnosis of the disease is important to start appropriate treatment and prevent complications. As described in the presented case, the use of reverse syphilis test algorithm will enable to reach the correct diagnosis of the infection. If the result of the treponemal test is positive and the RPR test is negative, prozone phenomenon should be considered and the RPR test should be repeated with serial serum dilutions.

Background: Screening tests for human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV) and syphilis infections performed in at-risk population show a higher number of positive tests compared to those carried out in the general population. 'Test & Counselling' Ambulatory of Infectious Disease Clinic (T&C-IDC) and Sexually Transmitted Diseases Ambulatory of Dermatology Unit (STDs-DU) of Modena began collaboration in 2010 and adopted a common diagnostic serological profile since 2013., Objectives: The main objective was to analyse the number of screening tests performed in the T&C-IDC and STDs-DU, comparing the results obtained after the adoption of the shared protocol with the previous period. The secondary aim was to evaluate the linkage to care of newly diagnosed patients., Methods: Consecutive patients referred to the T&C-IDC and STDs-DU from January 2010 to December 2016, with at least one performed screening test for HIV, HBV, HCV and syphilis were enrolled. Referral of patients with a new infection was obtained by capture-recapture methods in hospital databases., Results: During the 7-year observation, we collected 13 117 admittances for 9154 patients. A significant increase in the number of screening tests (P < 0.001) and ratio between tests and admissions (P = 0.002) was observed. A total of 644 (7.0%) people with at least one infection were diagnosed. Among these, the most common was syphilis (41.9%), followed by HBV (25.7%), HCV (21.4%) and HIV (10.9%). Syphilis occurred predominantly in Italians (72.5%) and males (75.7%), as like as HCV, while foreign-born (85.5%) mainly harboured HBV infection. HIV diagnosis was detected more frequently among males (67.1%) with a similar proportion between Italians and foreign-born. Five hundred and forty-three out of 644 (84.3%) patients were linked to care., Conclusion: The collaboration between T&C-IDC and STDs-DU has proven to work well increasing the diagnosis over the time and obtaining good results in linkage to care., (© 2018 European Academy of Dermatology and Venereology.)

Background: In this study, we evaluate the performance of the Syphilis Health Check (SHC) in clinical and laboratory settings using fingerstick whole blood and serum., Methods: Fingerstick whole blood and serum specimens from adult patients (n = 562) without prior syphilis history presenting at 2 county health department STD clinics in North Carolina were tested. Fingerstick specimens were tested with the SHC in clinic, and serum specimens were tested at the North Carolina State Laboratory of Public Health with: (1) qualitative rapid plasma reagin, (2) treponemal EIA, and (3) SHC. Sensitivity and specificity were calculated with 95% confidence intervals., Results: The fingerstick whole blood had a sensitivity of 100% (7 of 7) and specificity of 95.7% (531 of 555), compared with consensus reference testing (CRT) (rapid plasma reagin and EIA reactive), but a sensitivity of 50% (8 of 16), and specificity of 95.9% (523 of 546), when compared with the treponemal EIA. Both laboratory-based SHC on serum and whole-blood SHC performed similarly, compared with CRT, and the treponemal EIA alone. Twenty-four specimens SHC reactive on whole blood were nonreactive by CRT. In 8 of these 24 cases, STD clinic staff reported difficulty reading the test line for the SHC. Of the fingerstick whole-blood SHC reactive specimens, only 14 of 31 were also serum SHC reactive., Conclusions: The SHC on whole blood appears to be sensitive at detecting patients likely to have syphilis and could be an option for testing among high-risk populations. However, given challenges in interpreting SHC test results, adequate training of persons performing testing and ongoing quality assurance measures are key.

Background: Treponemal immunoassays are increasingly used for syphilis screening with the reverse sequence algorithm. There are few data describing performance of treponemal immunoassays compared to traditional treponemal tests in patients with and without syphilis., Methods: We calculated sensitivity and specificity of 7 treponemal assays: (1) ADVIA Centaur (chemiluminescence immunoassay [CIA]); (2) Bioplex 2200 (microbead immunoassay); (3) fluorescent treponemal antibody absorption test (FTA-ABS); (4) INNO-LIA (line immunoassay); (5) LIAISON CIA; (6) Treponema pallidum particle agglutination assay (TPPA); and (7) Trep-Sure (enzyme immunoassay [EIA]), using a reference standard combining clinical diagnosis and serology results. Sera were collected between May 2012-January 2013. Cases were characterized as: (1) current clinical diagnosis of syphilis: primary, secondary, early latent, late latent; (2) prior treated syphilis only; (3) no evidence of current syphilis, no prior history of syphilis, and at least 4 of 7 treponemal tests negative., Results: Among 959 participants, 262 had current syphilis, 294 had prior syphilis, and 403 did not have syphilis. FTA-ABS was less sensitive for primary syphilis (78.2%) than the immunoassays or TPPA (94.5%-96.4%) (all P ≤ .01). All immunoassays were 100% sensitive for secondary syphilis, 95.2%-100% sensitive for early latent disease, and 86.8%-98.5% sensitive in late latent disease. TPPA had 100% specificity., Conclusions: Treponemal immunoassays demonstrated excellent sensitivity for secondary, early latent, and seropositive primary syphilis. Sensitivity of FTA-ABS in primary syphilis was poor. Given its high specificity and superior sensitivity, TPPA is preferred to adjudicate discordant results with the reverse sequence algorithm over the FTA-ABS., (Published by Oxford University Press for the Infectious Diseases Society of America 2018.)

Objectives: In South Korea, automated T. pallidum Latex Agglutination (TPLA) based on turbidoimmunoassays and immunochromatographic assay (ICA) are widely used for syphilis diagnosis. However, there is sparse data on the validation of these assays in the reverse-sequence algorithm setting., Methods: We assessed 551 specimens submitted for syphilis testing. We compared varying reverse-sequence algorithms using combinations of the Cobas Syphilis EIA (Roche Diagnostics, Mannheim, Germany), Mediace TPLA (Sekisui Medical Co., Tokyo, Japan), TPPA (Fujirebio Inc., Tokyo, Japan), and SD Bioline ICA (Standard Diagnostic, Yongin, Korea). We also evaluated modified algorithms incorporating a cut off of high specificity for EIA and TPLA using receiver operating characteristic curves., Results: The agreement was almost perfect between EIA and TPLA (Kappa, 0.953) and strong between TPPA and ICA (Kappa, 0.887). Among TPPA positive and ICA negative specimens, 67% of the specimens were from individuals with syphilis histories. Compared to EIA/RPR/TPPA, the agreement with EIA/RPR/ICA, TPLA/RPR/TPPA and TPLA/RPR/ICA were almost perfect (Kappa, 0.930, 0.995 and 0.914, respectively). When a cut off of 95% specificity was applied, the number of TPPA tests could be reduced by 44% and 40% in EIA and TPLA, respectively., Conclusions: TPLA showed almost perfect agreement with EIA and that it could be used in the site of EIA in a reverse sequence algorithm. ICA showed a lower detection rate than TPPA as a 2nd treponemal test and should be used with caution. With cut offs of higher specificity, more efficient reverse-sequence algorithms can be made possible., (Copyright © 2018 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.)

The use of technology for preparing components for immunofluorescence reaction (RIF) in a number of clinical diagnostic laboratories (CDL) in accordance with the recommendations of the Guidelines introduced by order of the RF Ministry of Health No 87 dated March 26, 2001 does not guarantee the required standardization of RIF preparation and conduct conditions. The latter is achieved by using the appropriate industrial production reagent kits in the СDL practice., Competing Interests: The authors declare no conflict of interest.

Background: Syphilis is a cause of morbidity and mortality and is of particular concern in pregnancy in low-income countries because of the risks associated with maternal-fetal transmission. Ugandan national guidelines recommend a nontreponemal rapid plasma reagin (RPR) followed by treponemal testing for diagnosis of syphilis. The RPR test confirms a reactive specific treponemal test, or confirms serological "cure" with a 4-fold dilutional decrease; RPR is beset with technical and biological limitations, making accurate diagnosis and appropriate treatment problematic. The aim of this analysis was to compare performance of RPR testing in different laboratories., Methods: Stored, freeze-thawed sera from 215 participants were additionally tested for RPR and dilutional titer in 2 different reference laboratories. Discrepant results were tested at a third reference laboratory which served as a tie-breaker. Equivalence in RPR titer was defined as within 2-fold or less. All patients with reactive rapid tests were treated as per Ugandan National Guidelines., Results: Of 215 sera, 97 (45.1%) were RPR reactive in clinic laboratory A, 81 (37.7%) and 65 (30.2%) were RPR reactive in laboratories B and C, respectively. All reported positive in laboratory C were positive in laboratory B. Discrepant results were tested in laboratory D. χ Test was highly significant (P = <0.001) for difference between each dyad of laboratories (A and B, A and C, and B and C) RPR results. There were significant differences between RPR titers by paired t test and Wilcox rank test (P = <0.001); with up to a 3-fold difference between laboratories. Two one-sided test approach demonstrated nonequivalence. Agreement between laboratories B-D, and C-D: 48 (98.0%) of 49 and 34 (69.4%) of 49, respectively (P = <0.001). Laboratories B and D showed no significant difference and had equivalent RPR titers. Laboratories C and D had different titers (P = <0.001) and were not equivalent., Conclusions: We found significant interlaboratory discrepant RPR results. A 3-fold difference in results is likely to be clinically significant and could result in undertreatment or overtreatment. These data demonstrate a key limitation of the RPR test and underline the urgent need for a more reproducible quantitative test than the current RPR for diagnosing and determining cure of syphilis.

Background: The sexually transmitted infection (STI) syphilis remains a public health problem globally. The serological detection of specific antibodies to Treponema pallidum is particularly important in the diagnosis of syphilis. The purpose of this study was to evaluate the newly developed Elecsys Syphilis assay and compare it with the local market well-established ARCHITECT Syphilis TP assay., Methods: A total of 1,097 clinical serum samples were obtained from routine diagnostic requests. All the serum or plasma samples were tested in parallel by Elecsys Syphilis assay and ARCHITECT Syphilis TP assay. Sensitivity, specificity, and agreement assay were verified. The inconsistent samples confirmed with a recombinant immunoblot assay as gold standard test., Results: The diagnostic performances of the two assays were very similar: both Elecsys Syphilis and ARCHITECT Syphilis TP assay performed with a sensitivity of 100% (95% CI, 85.7 to 100%) and 100% (95% CI, 85.7 to 100%), whereas the specificity was 99.90% (95% CI, 99.5 to 99.90%) and 99.49% (95% CI, 99.0 to 99.6%), respectively. The consistency in positive results between Elecsys and ARCHITECT Syphilis TP assay was 79.3%. The consistency in negative results between Elecsys and ARCHITECT Syphilis TP assay was 99.7%. The overall consistency between Elecsys and ARCHITECT Syphilis TP assay was 99.1%., Conclusions: The Elecsys Syphilis assay can demonstrate excellent diagnostic sensitivity and specificity and correlate well with ARCHITECT Syphilis TP assay. It is a reliable and appropriate assay for routine use in a diagnostic laboratory.,

The usefulness of an automated latex turbidimetric rapid plasma reagin (RPR) assay, compared to the conventional manual card test (serial 2-fold dilution method), for the diagnosis of syphilis and evaluation of treatment response remains unknown. We conducted (i) a cross-sectional study and (ii) a prospective cohort study to elucidate the correlation between automated and manual tests and whether a 4-fold decrement is a feasible criterion for successful treatment with the automated test, respectively, in HIV-infected patients, from October 2015 to November 2017. Study i included 518 patients. The results showed strong correlation between the two tests ( r = 0.931; P < 0.001). With a manual test titer of ≥1:8 plus a positive Treponema pallidum particle agglutination (TPPA) test as the reference standard for diagnosis, the optimal cutoff value for the automated test was 6.0 RPR units (area under the curve [AUC], 0.998), with positive predictive value (PPV) of 92.5% and negative predictive value (NPV) of 99.4%. Study ii enrolled 66 men with syphilis. Their RPR values were followed up until after 12 months of treatment. At 12 months, 77.3% and 78.8% of the patients achieved a 4-fold decrement in RPR titer by the automated and manual test, respectively. The optimal decrement rate in RPR titer by the automated test for a 4-fold decrement by manual card test was 76.54% (AUC, 0.96) (PPV, 96.1%; NPV, 80.0%). The automated RPR test is a good alternative to the manual test for the diagnosis of syphilis and evaluation of treatment response and is more rapid and can handle more specimens than the manual test without interpersonal variation in interpretation., (Copyright © 2018 American Society for Microbiology.)

Objective: To synthesize lessons from comparison of results obtained from the immuno-chromatographic SD Bioline testing method and the chemiluminescent micro-particle immunoassay Architect in the diagnosis of syphilis at Livingstone Central hospital laboratory., Results: The specificity and sensitivity of SD Bioline syphilis 3.0 against the chemiluminescent immunoassay using the Architect syphilis Treponema pallidum (TP) was 85.3% and 91.3% respectively with substantial agreement between the two test methods (88%, ĸ  = 0.76; p < 0.0005). We recommend further comprehensive study with a larger sample size and clinical details to ascertain the validity of our findings. We also recommend using a non-treponemal test with the current treponemal tests being used to aid diagnosis.

Background: Health departments prioritize investigations of reported reactive serologic tests based on age, gender, and titer using reactor grids. We wondered how reactor grids are used in different programs, and if administratively closing investigations of low-titer tests could lead to missed primary syphilis cases., Methods: We obtained a convenience sample of reactor grids from 13 health departments. Interviews with staff from several jurisdictions described the role of grids in surveillance and intervention. From 5 jurisdictions, trends in reactive nontreponemal tests and syphilis cases over time (2006-2015) were assessed by gender, age, and titer. In addition, nationally-reported primary syphilis cases (2013-2015) were analyzed to determine what proportion had low titers (≤1:4) that might be administratively closed by grids without further investigation., Results: Grids and follow-up approaches varied widely. Health departments in the study received a total of 48,573 to 496,503 reactive serologies over a 10-year period (3044-57,242 per year). In 2006 to 2015, the number of reactive serologies increased 37% to 169%. Increases were largely driven by tests for men although the ratios of tests per reported case remained stable over time. Almost one quarter of reported primary syphilis had low titers that would be excluded by most grids. The number of potentially missed primary syphilis cases varied by gender and age with 41- to 54-year-old men accounting for most., Conclusions: Reactor grids that close tests with low titers or from older individuals may miss some primary syphilis cases. Automatic, computerized record searches of all reactive serologic tests could help improve prioritization.

Objectives This study assesses U.S. state laws related to prenatal syphilis screening, including whether these laws align with CDC screening recommendations and include legal penalties for failing to screen. Methods Statutes and regulations regarding syphilis screening during pregnancy and at delivery effective in 2016 were examined for all 50 U.S. states and the District of Columbia (DC). Targeted search terms were used to identify laws in legal research databases. The timing of the screening mandates for each state law was coded for: (1) first visit, (2) third trimester, and (3) delivery. Descriptive statistics were calculated to examine the number of states with each type of requirement and whether requirements adhered to the CDC STD treatment guidelines. Results Only six states (11.8%) do not require prenatal syphilis screening. Of states with screening requirements (n = 45), the majority (84.3%) require testing at first prenatal visit or soon after. 17 states (33.3%) require screening during the third trimester with five requiring screening only if the patient is considered at high risk. 8 (15.7%) states require screening at delivery with five requiring testing only if the woman is at high risk. 14 (27.5%) states include punishments for failing to screen (civil penalties, criminal penalties and license revocation). Conclusions for Practice Most states had prenatal syphilis screening requirements; a minority corresponded to or extended CDC recommendations. States vary in when they require testing, who must be tested, and whether a failure to screen could result in a punishment for the provider.

Background: Two serologic syphilis screening algorithms recommended by the US Centers for Disease Control and Prevention (US CDC) and the European Centre for Disease Prevention and Control (ECDC), respectively, are commonly used for syphilis screening; however, which one is optimal remains to be determined., Methods: We conducted a prospective study of 119891 subjects to analyze the consistency of the US CDC- and ECDC-recommended algorithms. The US CDC-recommended algorithm begins with a treponemal immunoassay, followed by a rapid plasma reagin (RPR) test. RPR-nonreactive samples are confirmed by the Treponema pallidum particle agglutination assay (TPPA). The ECDC-recommended algorithm begins with a treponemal immunoassay, followed by a confirmatory treponemal test. If the confirmatory test is reactive, a quantitative nontreponemal assay is used to assess the disease activity and treatment response. In the present study, a total of 119891 serum samples from a large hospital (sixth largest in China) were included, and each sample was screened with a chemiluminescent immunoassay (CIA). CIA-reactive samples were then simultaneously tested with RPR and TPPA. The consistency of these 2 algorithms was determined by calculating the percentage of agreement and κ coefficient., Results: The overall percentage of agreement and κ value between these 2 algorithms were 99.996% and 0.999, respectively. The positivity rate for syphilis as determined by the US CDC- and ECDC-recommended algorithms was 1.43% and 1.42%, respectively., Conclusions: Our results suggest that the US CDC-recommended algorithm and the ECDC-recommended algorithm have comparable performances for syphilis screening in low-prevalence populations.

There has been a resurgence of syphilis diagnoses in Australia. We investigated whether our Treponema pallidum PCR test provides any additional diagnostic information over syphilis serology (chemiluminescence immunoassay [CMIA], Treponema pallidum particle agglutination [TPPA] assay, and the rapid plasma reagin [RPR] flocculation test). A retrospective audit of all T. pallidum PCR requests that came through our laboratory from January 2010 to June 2017 was conducted; data collected included age, gender, site of swab, and results from T. pallidum PCR, syphilis serology, and herpes simplex virus 1 (HSV-1) and HSV-2 PCRs. A total of 441 T. pallidum PCR tests were performed; on average, 3 T. pallidum PCRs per month were requested in 2011, and this rate increased to 17.2 requests per month in 2017. A total of 323 patients had both T. pallidum PCR and syphilis serology performed, with 67% of swabs taken from the genitals. T. pallidum PCR gave positive results for 61/323 (19%) patients; of these 61 patients, 59 (97%) also had positive syphilis serology results ( T. pallidum PCR sensitivity, 68%; specificity, 99%; positive predictive value, 97%; negative predictive value, 89%). Syphilis serology was positive for 91/323 patients (28%); of these 91 patients, 61 (66%) were also T. pallidum PCR positive (syphilis serology sensitivity, 97%; specificity, 88%; positive predictive value, 60%; negative predictive value, 99%). The Cohen's kappa value was 0.74, indicating substantial agreement between the two tests. Our results show that most patients with positive T. pallidum PCR results also had positive syphilis serology. Therefore, T. pallidum PCR adds little clinical value over serology for the diagnosis of syphilis in certain clinical settings., (Copyright © 2018 American Society for Microbiology.)

Background: Repeat syphilis is playing an increasing role in syphilis transmission in several populations. The assessment of repeat syphilis and response to treatment depends on accurately measuring intraindividual changes in non-treponemal tests. For a 0- to 6-month delta rapid plasma reagin (RPR) to be determined by routine individual RPR testing, samples are tested 6 months apart with differences in reagent batches, environmental conditions, and observers all leading to measurement errors. We hypothesized that conducting paired RPR testing (simultaneous testing of acute and convalescent samples) would enable a more accurate determination of delta RPR compared with individual testing., Methods: A total of 120 study participants with a new diagnosis of syphilis were followed up at 0, 3, 6, 9, 12, 18, and 24 months, with RPR testing performed via individual testing at each study visit and at any suspected repeat syphilis. Rapid plasma reagin paired testing was performed on samples from 0 and 6 months and at any suspected repeat syphilis., Results: The quantitative agreement ±1 dilution among paired and individual testing was 97.2%. There was no difference in the proportion with serofast status at 6 months: 21 (19.4%) and 19 (17.6%) according to paired and individual testing, respectively (P = 0.726). There was no statistically significant difference between 0- and 6-month delta RPR as determined by paired and individual testing in predicting seroresponse at 12 months (86.1% and 91.6% agreement with 12-month serofast/nonserofast classification, respectively; P = 0.262)., Conclusions: In our setting, individual testing performed equally well compared with paired testing. Follow-up of syphilis will remain onerous for the patient and the health care provider until new tests that can more accurately assess the response to therapy and repeat syphilis/treatment failure are developed.

Background: Syphilis testing conventionally relies on a combination of non-treponemal and treponemal tests. The primary objective of this study was to describe the positive predictive value (PPV) of a screening algorithm in a combination of a treponemal rapid diagnostic test (RDT) and rapid plasma reagin (RPR) test at Komfo Anokye Teaching Hospital (KATH), Ghana., Materials and Methods: From February 2014 to January 2015, 5 mL of venous blood samples were taken from 16 016 blood donors and tested with a treponemal RDT; 5 mL of venous blood was taken from 526 consenting initial syphilis sero-reactive blood donors. These RDT reactive samples were confirmed with an algorithm, applying the Vitros ® /Abbott-Architect ® algorithm as gold standard., Results: A total of 478 of 526 RDT reactive donors were confirmed positive for syphilis, making a PPV of 90·9%. Of the 172 (32·7%) donors who were also RPR positive, 167 were confirmed, resulting in a PPV of 97·1%. The PPV of the combined RDT and RPR (suspected active syphilis) testing algorithm was highest among donors at an enhanced risk of syphilis, family/replacement donors (99·9%), and among voluntary donors above 25 years (98·6%)., Discussion: Screening of blood donors by combining syphilis RDT and RPR with relatively good PPV may provide a reasonable technology for LMIC that has a limited capacity for testing and can contribute to the improvement of blood safety with a minimal loss of donors., (© 2016 British Blood Transfusion Society.)

Context: -Syphilis serology screening in laboratory practice is evolving. Traditionally, the syphilis screening algorithm begins with a nontreponemal immunoassay, which is manually performed by a laboratory technologist. In contrast, the reverse algorithm begins with a treponemal immunoassay, which can be automated. The Centers for Disease Control and Prevention has recognized both approaches, but little is known about the current state of laboratory practice, which could impact test utilization and interpretation., Objective: -To assess the current state of laboratory practice for syphilis serologic screening., Design: -In August 2015, a voluntary questionnaire was sent to the 2360 laboratories that subscribe to the College of American Pathologists syphilis serology proficiency survey., Results: -Of the laboratories surveyed, 98% (2316 of 2360) returned the questionnaire, and about 83% (1911 of 2316) responded to at least some questions. Twenty-eight percent (378 of 1364) reported revision of their syphilis screening algorithm within the past 2 years, and 9% (170 of 1905) of laboratories anticipated changing their screening algorithm in the coming year. Sixty-three percent (1205 of 1911) reported using the traditional algorithm, 16% (304 of 1911) reported using the reverse algorithm, and 2.5% (47 of 1911) reported using both algorithms, whereas 9% (169 of 1911) reported not performing a reflex confirmation test. Of those performing the reverse algorithm, 74% (282 of 380) implemented a new testing platform when introducing the new algorithm., Conclusion: -The majority of laboratories still perform the traditional algorithm, but a significant minority have implemented the reverse-screening algorithm. Although the nontreponemal immunologic response typically wanes after cure and becomes undetectable, treponemal immunoassays typically remain positive for life, and it is important for laboratorians and clinicians to consider these assay differences when implementing, using, and interpreting serologic syphilis screening algorithms.

Background: The reverse sequence algorithm is often used for prenatal syphilis screening by high-volume laboratories, beginning with a treponemal test such as the chemiluminescence immunoassay (CIA), followed by testing of CIA-positive (CIA(+)) specimens with the rapid plasma reagin test (RPR). The clinical significance of discordant serology (CIA(+)/RPR(-)) for maternal and neonatal outcomes is unknown., Methods: From August 2007 to August 2010, all pregnant women at Kaiser Permanente Northern California with discordant treponemal serology underwent reflexive testing with Treponema pallidum particle agglutination assay (TP-PA) and were categorized as "TP-PA confirmed" (CIA(+)/RPR(-)/TP-PA(+)) or "isolated CIA positive" (CIA(+)/RPR(-)/TP-PA(-)). Demographic variables and clinical data were abstracted from the medical record and compared by TP-PA status., Results: Of 194 pregnant women, 156 (80%) were CIA(+)/RPR(-)/TP-PA(-) and 38 (20%) were CIA(+)/RPR(-)/TP-PA(+). Among the 77 (49%) CIA(+)/RPR(-)/TP-PA(-) women who were retested, 53% became CIA(-). CIA(+)/RPR(-)/TP-PA(+) (n = 38) women were more likely to be older, have a prior history of sexually transmitted infections, and receive treatment for syphilis during pregnancy than women who were CIA(+)/RPR(-)/TP-PA(-) (all P < .005). Most pregnancies (189/194 [97.5%]) resulted in a live birth; there was no difference in birth outcomes according to TP-PA status and no stillbirths attributable to syphilis., Conclusions: Most pregnant women with discordant serology were CIA(+)/RPR(-)/TP-PA(-); more than half who were retested became CIA(-). CIA(+)/RPR(-)/TP-PA(-) serology in pregnancy is likely to be falsely positive. Reflexive testing of discordant specimens with TP-PA is important to stratify risk given the likelihood of false-positive results in this population., (© The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

Objective: To asses laboratory syphilis testing policies and practices among laboratories in the Americas., Methods: Laboratory directors or designees from PAHO member countries were invited to participate in a structured, electronically-delivered survey between March and August, 2014. Data on syphilis tests, algorithms, and quality control (QC) practices were analyzed, focusing on laboratories receiving specimens from antenatal clinics (ANCs)., Results: Surveys were completed by 69 laboratories representing 30 (86%) countries. Participating laboratories included 36 (52%) national or regional reference labs and 33 (48%) lower-level laboratories. Most (94%) were public sector facilities and 71% reported existence of a national algorithm for syphilis testing in pregnancy, usually involving both treponemal and non-treponemal testing (72%). Less than half (41%) used rapid syphilis tests (RSTs); and only seven laboratories representing five countries reported RSTs were included in the national algorithm for pregnant women. Most (83%) laboratories serving ANCs reported using some type of QC system; 68% of laboratories reported participation in external QC. Only 36% of laboratories reported data to national/local surveillance. Half of all laboratories serving ANC settings reported a stockout of one or more essential supplies during the previous year (median duration, 30days)., Conclusion: Updating laboratory algorithms, improving testing standards, integrating data into existing surveillance, and improved procurement and distribution of commodities may be needed to ensure elimination of MTCT of syphilis in the Americas., (Copyright © 2015. Published by Elsevier Ireland Ltd.)

Background and Objective: Little information is available on the rapid diagnostic testing for syphilis in Burkina Faso. The objectives of the study were (i) to assess the sensitivity and specificity of four on site rapid tests in comparison with Treponema pallidum haemagglutination assay (TPHA) as a gold standard and (ii) to evaluate the operational characteristics of those tests among health workers in a maternity unit., Methods: Four rapid syphilis tests commercially available in Burkina Faso were evaluated using archived serum samples and Treponema pallidum hemagglutination assay (TPHA) as the gold standard. Blood samples were collected between November 2011 and June 2012 from blood donors at the Regional Blood Transfusion Center of Ouagadougou. The sensitivity and specificity of the tests were calculated. Evaluation of operational characteristics such as clarity of pamphlet, complexity of technique, duration, was conducted in a first-level healthcare center with health workers in maternity unit., Results: Alere DetermineTM Syphilis was the most sensitive of the four rapid syphilis tests evaluated. It was followed by SD Bioline Syphilis 3.0, Cypress Diagnostics Syphilis Quick test and Accu-Tell ® Rapid Anti-TP, which was the least sensitive. The four tests demonstrated a good diagnostic specificity for syphilis (95-98%), and healthcare workers found them easy to use., Conclusions: The study allowed confirming the good performance of three of four rapid syphilis tests in Burkina Faso. More research will be conducted to assess the feasibility of introducing selected rapid tests for syphilis in antenatal care services.

Persons with multiple syphilis reinfections may play an important role in syphilis transmission. We analysed all syphilis tests carried out for people attending the HIV/sexually transmitted infection (STI) clinic at the Institute of Tropical Medicine, Antwerp, Belgium, from 1992 to 2012 to evaluate the extent to which syphilis reinfections were contributing to the syphilis epidemic in Antwerp. We then characterised the features of the syphilis infections in individuals with five or more episodes of syphilis. A total of 729 syphilis episodes were diagnosed in 454 persons. The majority of syphilis episodes occurred in people who had more than one episode of syphilis (445/729; 61%). A total of 10 individuals had five or more episodes of syphilis diagnosed over this period. All were men who have sex with men, HIV positive and on antiretroviral therapy. They had a total of 52 episodes of syphilis diagnosed and treated. In 38/42 of the episodes of repeat syphilis in these 10 individuals, they presented without any signs or symptoms of syphilis. Given that the majority of cases of incident syphilis in our clinic were persons with reinfections and that they frequently presented without signs of symptoms of syphilis, there is a strong case for frequent and repeated screening in all persons with a diagnosis of syphilis.

Background: Syphilis point-of-care tests may reduce morbidity and ongoing transmission by increasing the proportion of people rapidly treated. Syphilis stage and co-infection with HIV may influence test performance. We evaluated four commercially available syphilis point-of-care devices in a head-to-head comparison using sera from laboratories in Australia., Methods: Point-of-care tests were evaluated using sera stored at Sydney and Melbourne laboratories. Sensitivity and specificity were calculated by standard methods, comparing point-of-care results to treponemal immunoassay (IA) reference test results. Additional analyses by clinical syphilis stage, HIV status, and non-treponemal antibody titre were performed. Non-overlapping 95% confidence intervals (CI) were considered statistically significant differences in estimates., Results: In total 1203 specimens were tested (736 IA-reactive, 467 IA-nonreactive). Point-of-care test sensitivities were: Determine 97.3%(95%CI:95.8-98.3), Onsite 92.5%(90.3-94.3), DPP 89.8%(87.3-91.9) and Bioline 87.8%(85.1-90.0). Specificities were: Determine 96.4%(94.1-97.8), Onsite 92.5%(90.3-94.3), DPP 98.3%(96.5-99.2), and Bioline 98.5%(96.8-99.3). Sensitivity of the Determine test was 100% for primary and 100% for secondary syphilis. The three other tests had reduced sensitivity among primary (80.4-90.2%) compared to secondary syphilis (94.3-98.6%). No significant differences in sensitivity were observed by HIV status. Test sensitivities were significantly higher among high-RPR titre (RPR ≥ 8) (range: 94.6-99.5%) than RPR non-reactive infections (range: 76.3-92.9%)., Conclusions: The Determine test had the highest sensitivity overall. All tests were most sensitive among high-RPR titre infections. Point-of-care tests have a role in syphilis control programs however in developed countries with established laboratory infrastructures, the lower sensitivities of some tests observed in primary syphilis suggest these would need to be supplemented with additional tests among populations where syphilis incidence is high to avoid missing early syphilis cases.

Background: External quality assurance (EQA) programmes, which are routinely used in laboratories, have not been widely implemented for point-of- care tests (POCTs). A study was performed in ten health centres in Tanzania, to implement the use of dried blood spots (DBS) as an EQA method for HIV and syphilis (POCTs)., Method: DBS samples were collected for retesting at a reference laboratory and the results compared to the POCT results obtained at the clinic. In total, 2341 DBS samples were collected from 10 rural health facilities over a period of nine months, of which 92.5% were correctly collected and spotted., Results: The EQA method was easily implemented by healthcare workers under routine conditions in Northern Tanzania. For HIV, 967 out of 972 samples (99.5%) were concordant between DBS and POCT results. For syphilis, the sensitivity of syphilis tests varied between clinics with a median of 96% (25th and 75th quartile; 95-98%). The specificity of syphilis POCT was consistent compared to laboratory based test using DBS, with a median of 96% (25th and 75th quartiles; 95-98%)., Conclusion: Overall, the quality of testing varied at clinics and EQA results can be used to identify clinics where healthcare workers require remedial training, suggesting the necessity for stringent quality assurance programmes for POC testing. As Tanzania embarks on scaling up HIV and syphilis testing, DBS can be a useful and robust tool to monitor the quality of testing performed by healthcare workers and trigger corrective action to ensure accuracy of test results.

Background: Syphilis causes up to 1,500,000 congenital syphilis cases annually. These could be prevented if all pregnant women were screened, and those with syphilis treated with a single dose of penicillin before 28 weeks gestation. In recent years, rapid point-of-care tests have allowed greater access to syphilis screening, especially in rural or remote areas, but the lack of quality assurance of rapid testing has been a concern. We determined the feasibility of using dried blood spots (DBS) as specimens for quality assurance of syphilis serological assays., Methods: We developed DBS extraction protocols for use with Treponema pallidum particle agglutination assay (TPPA), Treponema pallidum haemagglutination assay (TPHA) and an enzyme immunoassay (EIA) and compared the results with those using matching plasma samples from the same patient., Results: Since DBS samples showed poor performance with TPHA and EIA (TPHA sensitivity was 50.5% (95% confidence interval: 39.9-61.2%) and EIA specificity was 50.4% (95% CI: 43.7-57.1%), only the DBS TPPA was used in the final evaluation. DBS TPPA showed an sensitivity of 95.5% (95% CI: 91.3-98.0%) and a specificity of 99.0% (95% CI: 98.1-99.5%) compared to TPPA using plasma samples as a reference., Conclusion: DBS samples can be recommended for use with TPPA, and may be of value for external quality assurance of point-of-care syphilis testing.

Background: While serological studies are the primary tool used to confirm the diagnosis of secondary syphilis, skin biopsies are often performed to control for potential false positives and negatives. Immunohistochemistry using anti-T. pallidum specific antibodies has proven to have a very high sensitivity and specificity for identification of spirochetes in biopsy specimens, but can occasionally fail to identify organisms in clinically and serologically confirmed cases., Methods: We report two cases of apparently negative biopsy specimens in which rare organisms were subsequently identified by detailed study of multiple additional sections., Results: Our experience suggests that the sensitivity of immunohistochemistry for syphilitic spirochetes may be improved by repeat immunostaining., (© 2012 The International Society of Dermatology.)

The External Quality Control Program of the Spanish Society of Infectious Diseases and Clinical Microbiology includes controls for bacteriology, serology, mycology, parasitology, mycobacteria, virology and molecular microbiology. This article presents the most important conclusions and lessons of the 2010 controls. As a whole, the results obtained in 2010 confirm the excellent skill and good technical standards found in previous years. However, erroneous results can be obtained in any laboratory and in clinically relevant determinations. The results of this program highlight the need to implement both internal and external controls to ensure maximal quality of microbiological tests(1)., (Copyright © 2011 Elsevier España S.L. All rights reserved.)

The performance of three serological tests manufactured in Belarus for the diagnosis of syphilis, i.e. a microprecipitation reaction (MPR) and two enzyme-linked immunosorbent assays (ELISAs) were compared with internationally recognized assays, namely the rapid plasma reagin test and the Treponema pallidum passive particle agglutination assay (TPPA). Sera from 392 consecutive patients attending Brest (Belarus) regional dermatovenereological dispensaries were tested. The sensitivity of the MPR test was low (77.3%) compared with the rapid plasma reagin test, while the specificity was high (100%). In contrast, both Belarusian ELISAs performed well when compared with the TPPA (sensitivities of 99.2% and 100%, specificities of 98.7% and 99.0%, respectively). There is a clear need to improve the sensitivity of the existing Belarusian MPR test or to use a more sensitive screening test in order to improve diagnosis of the disease in Belarus.

CDC recommends syphilis serologic screening with a nontreponemal test, such as the rapid plasma reagin (RPR) or Venereal Disease Research Laboratory (VDRL) test, to identify persons with possible untreated infection; this screening is followed by confirmation using one of several treponemal tests. Recently, the availability of automatable treponemal enzyme and chemiluminescence immunoassays (EIA/CIA) has led some laboratories to adopt a reverse sequence of screening in which a treponemal EIA/CIA is performed first, followed by testing of reactive sera with a nontreponemal test. To better understand the performance of reverse sequence screening for syphilis, CDC analyzed data from five laboratories that used reverse sequence screening during 2006-2010. This report describes the results of that analysis, which indicated that among sera reactive on initial screening with a treponemal EIA/CIA, 56.7% had a nonreactive RPR test. Among these discordant sera, 31.6% also were nonreactive by treponemal testing using Treponema pallidum particle agglutination (TP-PA) or fluorescent treponemal antibody absorbed (FTA-ABS) tests. Among discordant sera, the rate of nonreactive confirmatory treponemal tests was 2.9 times higher in a population with low prevalence of syphilis, suggesting that the low-prevalence population had a higher percentage of false-positive test results. Although CDC continues to recommend the traditional algorithm with reactive nontreponemal tests confirmed by treponemal testing, in this report CDC offers additional recommendations if reverse sequence syphilis screening is used.

Objectives: We undertook a prospective evaluation of the Qualpro Syphicheck-WB rapid syphilis test to measure its diagnostic performance and utility as a point-of-care (POC) screening test among female sex workers (FSWs) in Bangalore, India., Methods: From August 2008 to May 2009, FSWs without a laboratory-confirmed history of syphilis attending STI clinics in Bangalore underwent POC syphilis screening using finger-prick whole blood, with onsite treatment if indicated. Serum samples were collected for local laboratory offsite rapid plasma reagin (RPR) testing and reference laboratory RPR, Treponema pallidum haemagglutination assay (TPHA), and rapid syphilis testing. FSWs who participated in standard offsite RPR screening from August 2007 to May 2008 in the same clinics formed the comparison group for treatment coverage., Results: Of the 1617 women who underwent POC syphilis testing, 7.4% had laboratory evidence of active syphilis with reactive RPR and TPHA, and 3.7% had an RPR titre > or = 1:8. Compared with the reference RPR and TPHA, the sensitivity and specificity of the POC syphilis test were 70.8% (95% CI 62.7 to 79.0) and 97.8% (95% CI 97.1 to 98.5). Because of the low rate of women returning for their test results after offsite RPR screening, the proportion of women with active syphilis who were appropriately treated rose from 44.8% to 68.3% with the use of POC syphilis screening (p=0.003)., Conclusion: The Syphicheck-WB test utilising finger-prick whole blood has a relatively low sensitivity in detecting active syphilis. However, among hard-to-reach populations who may not return for follow-up treatment, POC screening with this assay could still confer an advantage over offsite RPR testing with respect to treatment coverage.