Serodia tp pa

The principle and the materials used for the syphilis testing kits, including Lumi‐TP (Lumi‐TP, Fujirebio Inc), Archi‐TP (Archi‐TP, Abbott), TPPA (Serodia TP‐PA: TPPA, Fujirebio Inc), ESPLINE TP (Fujirebio Inc), and Western blotting for TP, as shown in below Table 1. The Tp15‐17 antigen is a recombinant protein expressed in E. coli by fusing the N‐terminus of the Tp15 antigen and the C‐terminus of the Tp17 antigen, which are the main antigens of syphilis.

Five serum specimens included in the liquid and DTS EQA panels were tested at CDC using the qualitative and quantitative Rapid Plasma Reagin test (RPR, Arlington Scientific, Springville, UT) to detect nontreponemal antibodies and the T. pallidum Particle Agglutination assay (Serodia TP-PA, Fujirebio, Malvern, PA) to detect T. pallidum specific treponemal antibodies, following the manufacturers’ instructions. EQA panels were also tested using Genetic systems HIV-1/HIV-2 Plus O EIA (Bio-Rad Laboratories, Hercules, CA), Geenius HIV Supplemental Assay (Bio-Rad Laboratories) and Oraquick Advance HIV test (OraSure Technologies, Bethlehem, PA) to detect HIV antibodies. To assess the reproducibility of rapid tests on DTS EQA panels, the panels were reconstituted and tested (described below) using two FDA-cleared syphilis single or dual rapid tests, Syphilis Health Check (SHC, Diagnostics Direct, Stone Harbor, NJ) and Chembio DPP, following the manufacturers’ instructions for five consecutive days by the same tester.

From previous studies conducted in Ghana, one of the current yaws endemic countries, the prevalence of yaws among primary school children (with and without skin ulcers) was estimated at 2.5% [19 (link)]. In a first approach, we used this value as a design prevalence to calculate the required sample size that was needed to rule out the existence of yaws infection with an error probability of 5% in the subpopulation of children with skin ulcers in Tanzania. We calculated the sample size using the 1-Stage Freedom analysis tool implemented into Epitool software [20 , 21 (link)], setting the parameters as follows: population size was set to infinity, an error probability of 0.05 was used and the required test sensitivity and specificity of the Serodia Treponema Pallidum Particle Agglutination Assay (Serodia TPPA, FujireBio INC, Japan), which was used to screen for the presence of anti-T. pallidum antibodies, was set to 100% each, based on data provided by the manufacturer [22 (link)]. Under these conditions, a required sample size of at least 119 children resulted. If the design prevalence was strengthened to 2.0%, the minimum sample size amounted to 149 children. In both cases, design prevalence at 2.5 and 2.0%, the actual sample size in the study exceeded the calculated values.

The objective of this study was to carry out a multi-country concurrent accuracy evaluation of the ADVIA Centaur® Syphilis CLIA assay (Siemens Healthcare) compared to the reference TPPA (SERODIA-TP·PA®; Fujirebio Diagnostics) for syphilis screening (serum samples) amongst a sample of MSM attending the Infectious Disease Department in Verona (Italy), the GenitoUrinary (GU)-clinic in the Mater Dei Hospital, L-Imsida (Malta) and the Brighton & Hove Sexual Health and Contraception Service (SHAC) in Brighton (UK). Using the same protocol and criteria, an additional sample of patients (MSM) was enrolled at the Verona site in the framework of an EU-funded project called Sialon [11 (link)].

All the serum were separated by 3500 rpm centrifuge 10 minutes, after room temperature for 1 hour. The diagnosed serum, interference serum, and threshold serum were stored in −80°C, redissolve and mix well before testing.
All the serum were tested in ARCHITECT i2000SR (ARCHITECT Syphilis TP Abbott Laboratories, Wiesbaden, Germany, lot number 41537LI00) and ROCHE E601 (Elecsys Syphilis assay, Roche Diagnostics GmbH, Penzberg, Germany, lot number 17889301). All the results were expressed as a S/CO ratio, with a S/CO of <1.0 indicating a nonreactive result and a S/CO of ≥1.0 a reactive result. Serodia TPPA (Fujirebio, Tokyo, Japan) which are agglutination-based assays. For the Serodia TPPA the agglutination pattern was inspected and the results expressed as titers. The samples were then subjected to confirmatory testing with Immunoblot (Mikrogen Diagnostic, Martinsried, Germany) and it is a RIBA, which expressed the results as positive, negative, and indeterminate. All results were interpreted according to the manufacturers’ guidelines. Samples with initial nonreactive result are considered negative for T pallidum antibodies.