Abstract
We reviewed relevant syphilis diagnostic literature to address the question “What diagnostic considerations should be taken into account when screening for syphilis using the traditional or ...reverse algorithm?” Improved laboratory diagnosis of syphilis is an important element of the effort to reduce syphilis rates. Screening for syphilis is performed using either a nontreponemal or treponemal test (part of the traditional or reverse algorithm, respectively). Both syphilis algorithms are used by laboratories. However, there are limited data on the performance and cost-effectiveness of the algorithms. An expert panel generated “key questions” in the laboratory diagnosis of syphilis. This paper pertains to the key factors that should be considered when deciding whether to screen for syphilis using either the traditional or the reverse algorithm. A systematic literature review was performed, and tables of evidence were created to address this question.
Sexually transmitted infections (STIs) such as syphilis and HIV remain to be a significant public health issue worldwide. Dual rapid point-of-care tests (POCTs) have shown promise for detecting ...antibodies to HIV and syphilis but have not been fully evaluated in the field. Our study supported the WHO ProSPeRo study on Sexually Transmitted Infection Point-of-Care Testing (STI POCT) by providing external quality assessment (EQA) for HIV and syphilis testing in reference laboratories and their associated clinical sites in seven countries.
HIV/syphilis serum liquid and dried tube specimen (DTS) panels were prepared by CDC. Liquid panels were distributed to the reference laboratories for three rounds of testing using commercially and locally available laboratory-based serological tests. DTS panels were sent to the clinical testing sites for 8 rounds of POC testing using the Abbott SD BIOLINE HIV/Syphilis Duo test (hereafter referred to as SD BIOLINE) and the Chembio Dual Path Platform (DPP) HIV-Syphilis assay. EQA panels were tested at CDC using the Rapid Plasma Reagin (RPR) test and the Treponema pallidum Particle Agglutination assay (TP-PA) for syphilis antibodies. Genetic Systems HIV-1/HIV-2 Plus O EIA, Geenius HIV Supplemental Assay and the Oraquick Advance HIV test were used to detect HIV antibodies in the EQA panels. Results from the reference laboratories and POCT sites were compared to those obtained at the CDC and a percentage agreement was calculated.
Qualitative RPR and TP-PA performed at the reference laboratories demonstrated 95.4-100% agreement with CDC results while quantitative RPR and TP-PA tests demonstrated 87.7% and 89.2% agreement, respectively. A 93.8% concordance rate was observed for qualitative HIV testing in laboratories. EQA testing at clinical sites using dual tests showed 98.7% and 99.1% agreement for detection of HIV antibodies and eight out of 10 sites had > 95.8% agreement for syphilis testing. However, two clinical sites showed only 65.0-66.7% agreement for SD BIOLINE and 84.0-86.7% for DPP, respectively, for syphilis testing.
Overall, laboratories demonstrated high EQA performance in this study. Both HIV/syphilis POCTs gave expected results in the clinic-based evaluations using DTS. However, testing errors were identified in a few testing sites suggesting the necessity for continuous training and monitoring the quality of POC testing.
Syphilis is a sexually transmitted disease (STD) caused by the bacterium Treponema palladium. The resurgence of syphilis in the last 2 decades is a major public health concern in the US. The national ...rate of congenital syphilis has increased 254% since 2016. However, syphilis diagnosis is still challenging, partially because of the overlapping and ambiguous clinical presentation, particularly during early infection.
Automated nontreponemal rapid plasma reagin (RPR) tests were recently introduced in the United States for syphilis testing and limited performance data are available. In collaboration with the ...Association of Public Health Laboratories, three public health laboratories (PHL) were chosen through a competitive selection process to evaluate the performance of three FDA-cleared automated RPR test systems: BioPlex 2200 Syphilis Total & RPR assay (Bio-Rad Laboratories), AIX 1000 (Gold Standard Diagnostics), and ASI Evolution (Arlington Scientific). Panels prepared at the CDC included: a qualitative panel comprised of 734 syphilis reactive/nonreactive sera; a quantitative panel of 50 syphilis reactive sera (RPR titer 1:64 to 1:1,024); and a reproducibility panel of 15 nonreactive and reactive sera (RPR titer 1:1 to 1:64). Panels were shipped frozen to the PHL and tested on the automated RPR systems following manufacturers' instructions. Prior test results were blinded to all laboratories. When compared to manual RPR (Arlington Scientific) performed at the CDC as a reference test, the qualitative panel results demonstrated an overall concordance of 95.9% for AIX 1000, 94.6% for ASI Evolution, and 92.6% for Bioplex RPR; quantitative panel showed within range titer of 2-fold for 94% of specimens for AIX 1000, 68% for ASI Evolution, and 64% for BioPlex RPR, and the reproducibility testing panel demonstrated point estimates ranging from 69 to 95%. Automated RPR instruments could reduce turnaround time and minimize interpretation errors. However, additional evaluations with more specimens could assist laboratories with implementing automated RPR tests and understanding their limitations.
•Refrigerated storage stability of specimens was evaluated using syphilis tests•Syphilis reactive serum and plasma showed antibody stability for 3 to 16 weeks•Higher antibody stability was noted for ...syphilis sera compared to plasma specimens
The effect of extended refrigerated storage of 14 serum and plasma specimens on 5 syphilis serologic tests was evaluated for 16 weeks. Higher stability of nontreponemal and treponemal antibodies in serum was recorded compared to plasma. Described work may provide insights on refrigerated specimens’ stability and suitability for syphilis tests.
The coronavirus disease 2019 (COVID-19) pandemic reduced the sexually transmitted infection (STI) testing volume due to social-distancing and stay-at-home orders, among other reasons. These events ...highlighted previously known benefits of at-home STI self-testing or specimen self-collection and accelerated testing demand via telemedicine. We review testing outside traditional clinical settings. We focus on three curable bacterial STIs among the top 10 U.S. nationally notifiable conditions with screening recommendations: syphilis, gonorrhea (Neisseria gonorrhoeae, also known as the gonococcus GC), and chlamydia (Chlamydia trachomatis). At least 19 million GC/C. trachomatis (GC/CT) screening or diagnostic tests are performed annually, presenting a considerable challenge during the pandemic. Unlike for HIV, STI at-home tests are currently not commercially available. However, innovative telemedicine providers currently offer services where specimen self-collection kits are mailed to patients at home who then ship them to laboratories for processing. We discuss technical and regulatory aspects of modifications for home-based specimen self-collection. The telemedicine provider typically manages and communicates results, provides linkage to care, and is responsible for billing and case reporting. We also describe rapid testing devices in development that may present an opportunity for future self-testing. In summary, COVID-19 has accelerated the evaluation and development of STI self-tests and specimen self-collection. The remaining obstacles are high price, regulatory approval, support for laboratories offering the service, and uncertainty regarding whether target populations with the greatest need are reached effectively. However, increased testing, convenience, and privacy are potential benefits that may enhance uptake and outlast the pandemic.
The present study showed the suitability of bioactive glass-ceramics for application as bioactive coating on Ti based biomedical implants. The desired properties of bioactive glass-ceramic coating ...were obtained through controlled crystallization. XRD, optical microscopy, SEM in association with EDX data showed the phase composition and morphology of the glass-ceramic coatings. Microhardness distribution across the coated substrates and the scratch resistance property of the coatings were varied for the differently heat treated coated substrates. The bioactivity of the fluroapatite based glass-ceramic coating on Ti6Al4V substrate was investigated in vitro in simulated body fluid (SBF) solution. After immersion in SBF solution the glass-ceramic coating surface was characterized by SEM, EDX analysis and the elemental compositional change of the SBF solution was determined by chemical analysis technique. SEM, EDX analysis and chemical analysis indicated that the glass-ceramic coatings reacted with the SBF solution and formed fluroapatite layer on their surfaces.
•Use of conventional enamelling technique to prepare bioactive glass-ceramic coating on Ti based substrate.•Attainment of bioactive glass-ceramic coating of varied microstructure and properties.•Achievement of fluroapatite based bioactive glass-ceramic coating suitable for Ti based implants.
The present investigation demonstrated the comparative studies on interfacial joint strength of the alumina-alumina joints fabricated by conventional and microwave-assisted brazing techniques using ...scratch test method. Scratch tests were performed on cross-sectional surfaces of the alumina joints under steadily increasing normal loads up to 140 N. The scratches were made with a Rockwell C hardness tester stylus with 200 µm radius. The response of the joints was investigated by measuring the fluctuations in the tangential force during scratch test as well as by the examination of the scratch tracks. It was observed that microwave brazed joint had better interfacial joint strength in comparison to the conventionally brazed joint.
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