DOCSLIB.ORG

Evaluation of Rapid Diagnostic Tests: Syphilis

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Evaluation of Rapid Diagnostic Tests: Syphilis EVALUATING DIAGNOSTICS Evaluation of rapid diagnostic tests: syphilis WHO/TDR Sexually Transmitted Diseases Diagnostics Initiative Syphilis is a curable sexually transmit- countries2,3. Approximately 30% of preg- I. DIAGNOSTIC TESTS FOR SYPHILIS ted infection caused by the bacterium nant women with syphilis will give birth to T. pallidum cannot be cultured in the labora- Treponema pallidum. The infection can a stillborn baby, and another 30% to a live tory, but can be identified in lesions using also be passed from a mother to her fetus baby with congenital syphilis, a condition dark-field or fluorescent microscopy or by during pregnancy. As a cause of genital ulcer which has a range of severe effects, includ- molecular techniques. As most infected indi- disease, syphilis has been associated with ing growth retardation, and which can have viduals are asymptomatic or have transient an increased risk of HIV transmission and a mortality rate of up to 50%. These condi- lesions, serological tests are the diagnostic acquisition. tions are preventable if infected mothers test of choice for detection of syphilis9. The Most infected individuals have no are identified before the third trimester of characteristics of the commonly used sero- symptoms and therefore a serological test pregnancy, and treated appropriately. logical tests for syphilis are shown in TABLE 1. must be used to screen for infection. The Early detection and treatment is crucial Simple flocculation assays, such as the WHO estimates that 12 million new cases for preventing severe long-term complica- rapid plasma reagin (RPR) test, are widely of syphilis occur every year, most of which tions in the patient and the adverse preg- used for serodiagnosis of, or screening for, are in settings where there is limited or no nancy outcomes detailed above. syphilis. These tests detect antibodies to access to laboratory screening services1. Treatment also prevents further trans- phospholipid antigens such as cardiolipin. Left untreated, syphilis can eventually mission of the infection. The World Anti-cardiolipin antibodies can occur in a cause severe granulomatous lesions and Development Report cites antenatal screen- range of tissue-damaging diseases in mam- cardiovascular or neurological damage. ing and treatment for syphilis as one of the mals; these tests are therefore not specific Syphilis in pregnancy is a major cause of most cost-effective health interventions for T. pallidum infection and are commonly adverse pregnancy outcome in developing available4–8. referred to as ‘non-treponemal’ tests. Table 1 | Characteristics of serological tests for syphilis Non-treponemal tests Treponemal tests Test characteristic RPR VDRL Rapid test EIA TPPA/TPHA FTA-ABS Specimen Serum or plasma Serum or plasma Serum or whole Serum or plasma Serum or plasma Serum or plasma blood Sensitivity 86–100% 78–100% 84–98% 82–100% 85–100% 70–100% Specificity 93–98% 98–100% 94–98% 97–100% 98–100% 94–100% Ease of use Easy Easy Easy Moderate Complex Complex Level of use Exam room, Exam room, Exam room, Intermediate lab, Reference lab Reference lab on-site lab on-site lab on-site lab reference lab Equipment required Rotator, Light microscope, None Incubator, microwell Incubator Fluorescence refrigerator refrigerator plate washer and microscope reader Training Minimal Minimal Minimal Moderate Extensive Extensive Average cost US$ 0.5 US$ 0.5 US$ 0.19–3 US$ 3 US$ 3 US$ 3 Comments Reagents require Reagents require Most tests can be Allows high- Used as Used as refrigeration refrigeration stored at room throughput confirmatory confirmatory test; temperature for screening; test; does not does not distinguish 9–18 months does not distinguish distinguish between prior between prior between prior treated and active treated and active treated and active infection infection infection EIA, enzyme immunoassay; FTA-ABS, fluorescent treponemal antibody-absorption test; RPR, rapid plasma reagin test; TPHA/TPPA, Treponema pallidum haemagglutination assay/ Treponema pallidum particle agglutination assay; VDRL, venereal diseases research laboratory test. NATURE REVIEWS | MICROBIOLOGY DECEMBER 2006 | S33 © 2006 Nature Publishing Group EVALUATING DIAGNOSTICS | SYPHILIS (TPHA) or the closely related T. pallidum high prevalence settings where large num- particle-agglutination assay (TPPA). These bers of the target population have already confirmatory tests are more technically been screened and treated. Some suggested demanding and are not widely available in algorithms for use of rapid tests are shown in most developing countries outside reference FIGURE 120,21 and are discussed below. laboratories. In settings where RPR is not available, an RDT can be used to increase access to II. THE NEED FOR EVALUATION OF testing or for prenatal screening to prevent SYPHILIS RDTs congenital syphilis. Until recently, serological testing for syphilis In settings where non-treponemal tests, required a laboratory with trained person- such as the RPR test, are available, it might nel, refrigeration for the storage of reagents be possible to use RDTs as a screening test, and electricity to run equipment such as a and then perform quantitative non-trepone- refrigerator, centrifuge and shaker. As such mal tests to determine whether the patient facilities are generally not available in remote has an active infection. This approach is areas, blood or serum samples must be trans- useful in areas of low disease prevalence. By ported to regional or central facilities for test- selecting combinations of RDTs, it might ing. The results are therefore only available also be possible to use a sensitive RDT as a days or weeks after testing10 and specimens screening test and a more specific RDT as a or results can sometimes be lost in transit. It confirmatory test. is common for individuals who are tested not Targeting syphilis screening to at-risk to return for their test results or treatment, individuals is cost-effective. Given the resulting in adverse clinical outcomes, con- potentially serious sequelae of syphilis and tinued transmission of infection and wasted the increased risk of HIV transmission, the resources. following groups should be targeted for Simple, point-of-care Treponema-specific screening: rapid diagnostic tests (RDTs) are now com- • Pregnant women (to prevent congenital mercially available11–20. These tests can use syphilis) whole blood from a finger prick as well as • Individuals with, or at risk of, contracting, serum or plasma. They might be suitable for sexually transmitted infections (STIs) use in primary healthcare settings for the • Sex workers diagnosis of syphilis but until recently, there • Clients of sex workers were only limited data on their performance • Men who have sex with men characteristics. Evaluating the performance • Intravenous drug users of both current and future tests, their utility Consecutive patients of the desired in a disease control programme and their target population presenting to clinics at acceptability to patients and healthcare pro- the evaluation sites should be informed viders will improve the diagnosis of syphilis about the study and asked to participate. in primary healthcare settings in developing Patients who give consent should undergo countries and reduce unnecessary treatment. an interview and a physical examination Figure 1 | Suggested rapid diagnostic test according to the routine clinic protocol at algorithms and treatment decision points for III. GENERAL ISSUES IN STUDY DESIGN the site. Participants can be asked ques- syphilis. Treatment includes treating patients 1. Reference standards tions concerning their age, gender, history and contacts, counselling, recommending con- dom use and offering HIV testing. RPR, rapid The reference standard test for Treponema- of STIs, recent STI treatment history and plasma reagin test. specific tests should be TPHA, TPPA, pregnancy status, as suggested in the sample enzyme immunoassay (EIA) or the fluores- data-collection form shown in APPENDIX 1. cent treponemal antibody absorption test A sample informed consent form is shown False-positive results are often encountered, (FTA-ABS). Each test should be performed in APPENDIX 2. especially in pregnant women, leading to on sera by laboratory staff, according to the unnecessary treatment. Some common manufacturer’s directions. IV. FACTORS AFFECTING TEST conditions associated with false-positive PERFORMANCE test results are malaria, tuberculosis, viral 2. Local epidemiology, choice of study 1. Specimen sampling and preparation fevers, trypanosomiasis, leprosy and other population and sampling RDTs can be used with whole blood, serum treponemal infections in addition to syphilis. The local epidemiology of syphilis is impor- or plasma. However, TPHA, TPPA and other Non-infectious causes of cross-reactivity tant in selecting the appropriate test. Once reference tests must be performed on serum include drug addiction, connective tissue positive, Treponema-specific tests, including and will require specimen transport to a disease, pregnancy and advanced age. the new point-of-care RDTs, usually remain laboratory. The stage at which the serum is Positive RPR results therefore need to positive throughout the patient’s life and so removed from the clotted blood will depend be confirmed with treponemal tests that cannot distinguish between past syphilis, on the circumstances. If the reference labo- use Treponema-specific antigens such as treated syphilis and syphilis that requires ratory is distant, it might
Load more

Recommended publications
  • Section 13. Laboratory Considerations
    Section 13. Laboratory Considerations Table of Contents 13.1 Overview and General Guidance 13.2 Specimen Labeling 13.3 Procedures for Specimens That Cannot be Evaluated 13.4 Use of LDMS 13.5 Documentation 13.6 Urine Testing 13.6.1 Specimen Collection 13.6.2 Pregnancy Testing 13.6.3 Chlamydia and Gonorrhea Testing 13.6.4 Urine Culture 13.7 Blood Testing 13.7.1 Specimen Collection and Initial Processing 13.7.2 HIV Testing 13.7.3 Syphilis Testing 13.7.4 Hematology Testing 13.7.5 Serum Chemistries 13.7.6 Plasma Storage 13.7.7 CD4+ T Cell Count 13.7.8 HIV RNA PCR 13.7.9 HIV DNA PCR 13.8 Testing of Vaginal and Cervical Specimens 13.8.1 Vaginal pH 13.8.2 Wet Mount for Candidiasis and BV 13.8.3 Rapid Test for Trichomoniasis 13.8.4 Vaginal Gram Stain 13.8.5 Papanicolaou (Pap) Test 13.8.6 Self-Administered Vaginal Swabs for PK and biomarker testing 13.8.7 Endocervical Swabs for Biomarker Analysis 13.8.8 Intra-Vaginal Ring Storage 13.8.9 Herpes Lesion Testing Table 13-1 Volume Guide for Plasma Storage Appendix 13-1 Overview of Laboratory Testing Locations, Specimens, and Methods for MTN-020 Appendix 13-2 MTN-020 Lab Specimen Processing Guidelines Appendix 13-3 LDMS Specimen Management Guide to Logging in MTN-020 Specimens Appendix 13-4 MTN-020 HIV Testing Algorithms Appendix 13-5 MTN Network Lab HIV Query Form Appendix 13-6 LDMS Tracking Sheets This section contains information on the laboratory procedures performed in MTN-020.
    [Show full text]
  • Use of the Diagnostic Bacteriology Laboratory: a Practical Review for the Clinician
    148 Postgrad Med J 2001;77:148–156 REVIEWS Postgrad Med J: first published as 10.1136/pmj.77.905.148 on 1 March 2001. Downloaded from Use of the diagnostic bacteriology laboratory: a practical review for the clinician W J Steinbach, A K Shetty Lucile Salter Packard Children’s Hospital at EVective utilisation and understanding of the Stanford, Stanford Box 1: Gram stain technique University School of clinical bacteriology laboratory can greatly aid Medicine, 725 Welch in the diagnosis of infectious diseases. Al- (1) Air dry specimen and fix with Road, Palo Alto, though described more than a century ago, the methanol or heat. California, USA 94304, Gram stain remains the most frequently used (2) Add crystal violet stain. USA rapid diagnostic test, and in conjunction with W J Steinbach various biochemical tests is the cornerstone of (3) Rinse with water to wash unbound A K Shetty the clinical laboratory. First described by Dan- dye, add mordant (for example, iodine: 12 potassium iodide). Correspondence to: ish pathologist Christian Gram in 1884 and Dr Steinbach later slightly modified, the Gram stain easily (4) After waiting 30–60 seconds, rinse with [email protected] divides bacteria into two groups, Gram positive water. Submitted 27 March 2000 and Gram negative, on the basis of their cell (5) Add decolorising solvent (ethanol or Accepted 5 June 2000 wall and cell membrane permeability to acetone) to remove unbound dye. Growth on artificial medium Obligate intracellular (6) Counterstain with safranin. Chlamydia Legionella Gram positive bacteria stain blue Coxiella Ehrlichia Rickettsia (retained crystal violet).
    [Show full text]
  • Syphilis Diagnosis: Three Cases with Increasing Treponemal Test Result After Therapy
    Acta Derm Venereol 2014; 94: 323–324 SHORT COMMUNICATION Syphilis Diagnosis: Three Cases with Increasing Treponemal Test Result after Therapy Henrik O. Larsson1*, Annika Johnsson2 and Anders Bredberg1 Departments of 1Medical Microbiology, and 2Dermatology and Venereology, Skane University Hospital, Lund University, Jan Waldenströms gata 59, SE- 205 02 Malmö, Sweden. *E-mail: [email protected] Accepted May 4, 2013 Epub ahead of print Oct 3, 2013 Serology is a main tool for syphilis diagnostic work used (the Captia Syphilis-Enzywell Treponema IgG and IgM, (1–3). According to a recent survey performed by the respectively, EIA from Diesse, Monteriggioni, Italy); the IgG method uses antigen-coated wells and IgM is determined by U.S. Centers for Disease Control and Prevention (CDC) capture technique; a value over 1.0 is considered to be reactive 56% of infectious disease specialists responded that they (7). Particle agglutination was done at serum dilution 80 with send a rapid plasma reagin (RPR) test to the laboratory no quantitation of the result (TPPA, Fujirebio, Tokyo, Japan). and treat presumptively for syphilis (if result is negative 18% repeat the RPR testing before treating the patient, and 17% treat only if RPR is positive) (4). However, a RESULTS clearly positive reaction may be missing at the first visit Case 1 was tested twice, at 6 days before and 112 of patients with active syphilis (5). Non-treponemal test days after treatment start (Fig. 1, upper panel). The (e.g. RPR and Venereal Disease Research Laboratory treponemal screening value is rising from 4 to a highly (VDRL)) reactivity is known to decrease in response to reactive value of 14, while the non-treponemal VDRL therapy, in contrast to the typically life-long persistence titre decreases from a weak 1 to negativity.
    [Show full text]
  • Medical Bacteriology
    LECTURE NOTES Degree and Diploma Programs For Environmental Health Students Medical Bacteriology Abilo Tadesse, Meseret Alem University of Gondar In collaboration with the Ethiopia Public Health Training Initiative, The Carter Center, the Ethiopia Ministry of Health, and the Ethiopia Ministry of Education September 2006 Funded under USAID Cooperative Agreement No. 663-A-00-00-0358-00. Produced in collaboration with the Ethiopia Public Health Training Initiative, The Carter Center, the Ethiopia Ministry of Health, and the Ethiopia Ministry of Education. Important Guidelines for Printing and Photocopying Limited permission is granted free of charge to print or photocopy all pages of this publication for educational, not-for-profit use by health care workers, students or faculty. All copies must retain all author credits and copyright notices included in the original document. Under no circumstances is it permissible to sell or distribute on a commercial basis, or to claim authorship of, copies of material reproduced from this publication. ©2006 by Abilo Tadesse, Meseret Alem All rights reserved. Except as expressly provided above, no part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without written permission of the author or authors. This material is intended for educational use only by practicing health care workers or students and faculty in a health care field. PREFACE Text book on Medical Bacteriology for Medical Laboratory Technology students are not available as need, so this lecture note will alleviate the acute shortage of text books and reference materials on medical bacteriology.
    [Show full text]
  • Rapid Syphilis Testing Protocol Wisconsin Department of Health Services STD Control Program
    Rapid Syphilis Testing Protocol Wisconsin Department of Health Services STD Control Program P-01832 June 2017 Table of Contents Bureau of Communicable Diseases (BCD) Staff Contact List ........................................................................ 3 Common Acronyms and Terms ..................................................................................................................... 4 Introduction and Background ....................................................................................................................... 5 Syphilis FAQ ................................................................................................................................................... 6 Rapid Syphilis Testing Algorithm ................................................................................................................... 9 Program Requirements ............................................................................................................................... 10 Agency Flow of Services .............................................................................................................................. 15 Rapid Syphilis Testing in Nontraditional or Outreach Settings ................................................................... 15 Syphilis Risk Assessment with Rapid Tests ................................................................................................. 17 Syphilis Health Check Testing Kit ...............................................................................................................
    [Show full text]
  • Evaluation of a Highly Sensitive Method of Measuring Syphilis TP Antibody, and a New Approach to Syphilis Testing
    Sysmex Journal International Vol. 22 No. 1 Evaluation of a Highly Sensitive Method of Measuring Syphilis TP Antibody, and a New Approach to Syphilis Testing Hiroshi SHIBATA, Hidehiko MORIYAMA, Yuki TANIGUCHI, Chikafumi MATSUDA and Atsushi NAGAI Central Clinical Laboratory, Shimane University Hospital 89-1 Enya, Izumo, Shimane, 693-8501 Japan. INTRODUCTION facilitates reaction between the sample (TP-Ab) and a biotinylated TP-Ag. In the next step, there is binding with Syphilis is a typical systemic sexually transmitted disease streptavidin-coated magnetic particles. Then, after that is caused by infection by Treponema pallidum (TP), bound/free (B/F) separation, the complex is further a pathogenic spirochete. Immunoserological tests with bound to ALP-labeled TP-Ag. After another B/F serum samples are generally used for testing TP separation, the chemiluminescent substrate CDP-Star is infection. These are typically TP antibody (TP-Ab) added and the intensity of luminescence measured. assays wherein a TP bacterial component is used as the We used VIRATROL (Sysmex) for examining the antigen, and serological test for syphilis (STS) that uses accuracy of the measurement, and an enzyme linked the phospholipid cardiolipin as the antigen. immunosorbent assay using TPauto·FS (KW) (ELSIA- In recent years, along with the advancement of testing TP; Sysmex) as the control for comparing the test results. methods, syphilis TP-Ab testing has been automated and Samples with disagreement of findings were investigated there have been considerable advances in improving through testing by TP hemagglutination assay (TPHA) sensitivity, speed and labor savings. We shall report here (Fujirebio Inc.), rapid plasma reagin (RPR) carbon the results of basic investigations on TP-Ab antigen test (Dainippon Sumitomo Pharma), and measurements using a recombinant TP antigen (TP-Ag) fluorescent Treponema antibody absorption test (FTA- and the automated immunoassay system HISCL-2000i ABS) (Nihon BCG Supply).
    [Show full text]
  • FTA-ABS Double Stain (Syphilis) IFA Kit
    DIAGNOSTIC AUTOMATION, INC. 23961 Craftsman Road, Suite D/E/F, Calabasas, CA 91302 Tel: (818) 591-3030 Fax: (818) 591-8383 [email protected] [email protected] www.rapidtest.com See external label 2°C-8°C Σ=10 x 10 tests Cat # 351010-DS FTA-ABS Double Stain (Syphilis) IFA Kit Cat # 351010-DS INTEDED USE The Diagnostic Automation, Inc. FTA-ABS Double Stain test system is designed to confirm positive non-treponemal reagin tests for syphilis and is for in vitro diagnostic use. This product is not FDA cleared (approved) for use in testing (i.e., screening) blood or plasma donors. SIGNIFICANCE AND BACKGROUND Serological procedures for syphilis are currently divided into two general groups of tests: 1. The non-treponemal antigen reagent screen tests, of which the Venereal Disease Research (VDRL) and Rapid Plasma Reagin Card (RPR) procedures are the most frequently employed. 2. The treponemal antigen tests, of which the Fluorescent Treponemal Antibody-Absorption (FTA- ABS), and more recently, the Fluorescent Treponemal Antibody-Absorption Double Stain (FTA- ABS-DS) test are the most commonly employed confirmatory test procedures (1-9). Although the nontreponemal tests such as the VDRL procedure provide a relatively simple and reliable means to screen syphilis patients, they also produce a significant number of biologically false positive DAI Code # 2 1 (BFP) reactions. These reactions are defined as patients whose sera give a positive VDRL reaction (usually weakly reactive or titer less than 1:8), a negative FTA-ABS and no history or physically findings to suggest syphilis (10-11). Consequently, a VDRL positive screen should be confirmed with a more specific test for syphilis such as the FTA-ABS procedure.
    [Show full text]
  • Laboratory Diagnosis of Sexually Transmitted Infections, Including Human Immunodeficiency Virus
    Laboratory diagnosis of sexually transmitted infections, including human immunodeficiency virus human immunodeficiency including Laboratory transmitted infections, diagnosis of sexually Laboratory diagnosis of sexually transmitted infections, including human immunodeficiency virus Editor-in-Chief Magnus Unemo Editors Ronald Ballard, Catherine Ison, David Lewis, Francis Ndowa, Rosanna Peeling For more information, please contact: Department of Reproductive Health and Research World Health Organization Avenue Appia 20, CH-1211 Geneva 27, Switzerland ISBN 978 92 4 150584 0 Fax: +41 22 791 4171 E-mail: [email protected] www.who.int/reproductivehealth 7892419 505840 WHO_STI-HIV_lab_manual_cover_final_spread_revised.indd 1 02/07/2013 14:45 Laboratory diagnosis of sexually transmitted infections, including human immunodeficiency virus Editor-in-Chief Magnus Unemo Editors Ronald Ballard Catherine Ison David Lewis Francis Ndowa Rosanna Peeling WHO Library Cataloguing-in-Publication Data Laboratory diagnosis of sexually transmitted infections, including human immunodeficiency virus / edited by Magnus Unemo … [et al]. 1.Sexually transmitted diseases – diagnosis. 2.HIV infections – diagnosis. 3.Diagnostic techniques and procedures. 4.Laboratories. I.Unemo, Magnus. II.Ballard, Ronald. III.Ison, Catherine. IV.Lewis, David. V.Ndowa, Francis. VI.Peeling, Rosanna. VII.World Health Organization. ISBN 978 92 4 150584 0 (NLM classification: WC 503.1) © World Health Organization 2013 All rights reserved. Publications of the World Health Organization are available on the WHO web site (www.who.int) or can be purchased from WHO Press, World Health Organization, 20 Avenue Appia, 1211 Geneva 27, Switzerland (tel.: +41 22 791 3264; fax: +41 22 791 4857; e-mail: [email protected]). Requests for permission to reproduce or translate WHO publications – whether for sale or for non-commercial distribution – should be addressed to WHO Press through the WHO web site (www.who.int/about/licensing/copyright_form/en/index.html).
    [Show full text]
  • Syphilis (Serology and Biological False Positive Phenomenon
    Br J Vener Dis: first published as 10.1136/sti.53.5.328 on 1 October 1977. Downloaded from British Journal of Venereal Diseases, 1977, 53, 328-336 Abstracts These selected abstracts and titles from the world literature are arranged in the following sections: Syphilis and other treponematoses Trichomoniasis (Clinical and therapy; serology and biologicalfalse Candidosis positive phenomenon; pathology and experimental) Genital herpes Gonorrhoea Other sexually transmitted diseases (Clinical; microbiology; therapy) Public health and social aspects Non-specific genital infection Miscellaneous Reiter's disease The RST is thought to offer the ad- Syphilis and other Syphilis (Serology and biological vantage of a stable antigen which gives a treponematoses (Clinical and false positive phenomenon smooth background with negative sera therapy) compared with the slightly coarse back- Evaluation of reagin screen, a new ground with the particulate RPR antigen.copyright. A. E. Wilkinson Infectious syphilis mimicking neoplastic serological test for syphilis disease J. D. DYCKMAN, R. D. WENDE, [Reprinted from Abstracts on Hygiene, by of the L. M. DRUSIN, C. SINGER, A. J. VALENTI, D. GANTENBEIN, AND R. P. WILLIAMS (1976). permission Editor.] AND D. ARMSTRONG (1977). Journal of Clinical Microbiology, 4, 145-150 Archives ofInternal Medicine, 137, Fluorescent treponemal antibody 156-160 The reagin screen test (RST) is carried out absorption (FTA-ABS) tests using blood on unheated serum on cards with a samples collected on filter paper The case histories are given of five lipoidal antigen stained with a blue dye. D. R. HOPKINS (1977). patients with lesions at first thought to be Its performance is compared with the American Journal of Tropical Medicine http://sti.bmj.com/ neoplasms but which were later shown to VDRL, RPR card, and FTA-ABS tests.
    [Show full text]
  • Practical Application of Quantitative Hisens Auto Rapid Plasma Reagin
    1) ORIGINAL ARTICLE DOI : 10.3947/ic.2009.41.3.154 Practical Application of Quantitative HiSens Auto Rapid Plasma Reagin Latex Turbidimetric Immunoagglutination for Diagnosing Syphilis; Comparison Analysis between Rapid Plasma Reagin Latex Turbidimetric Immunoagglutination Test and Rapid Plasma Reagin Card Test Hyun Yong Hwang, M.D., Mi Hyang Kim, M.D. Department of Laboratory Medicine, Kosin University College of Medicine, Busan, Korea Background : The purpose of this study was to evaluate validity of quantitative RPR LTIA, HiSens Auto RPR LTIA (HBi Corp., South Korea) and to decide an adequate cutoff value for syphilis screening. Materials and Methods : A total of 549 serums or plasma specimens from patients were tested with RPR LTIA and RPR card tests. Degree of agreement between the two methods was analyzed, and validity of RPR LTIA test was analyzed by receiver operating characteristic (ROC) curves. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, and ROC statistics of the RPR LTIA test were analyzed to decide an adequate cutoff value. Results : Agreement analysis showed slight to moderate agreement (k=0.093-0.588, P=0.000). Kappa value had its highest value at the cutoff value of 1.3 and 1.6 (k=0.588, P=0.000). Kappa value at the cutoff value of 1 ranked second (k=0.578. P=0.000). A plot of ROC curve showed a statistically valid result to differentiate between a syphilis test positive group and a syphilis test negative group (AUC=0.92, P=0.000). The cutoff values in RPR LTIA test ranged between 0.65 and 1.15 when both sensitivity and specificity were higher than 80%.
    [Show full text]
  • Seroprevalence of Treponema Pallidum Among
    Annals of African Medicine Vol. 4, No. 4; 2005:177 – 179 SYPHILIS IN A NIGERIAN PARAMILITARY AGENCY: NEED FOR TREATMENT POLICY 1 2 3 1 1 E. E. Nwokedi, Z. Iliyasu, A. U. Dikko, A. O. Azeez and B. Mohammed Departments of 1Medical Microbiology and Parasitology, 2Community Medicine and 3Physiology, Faculty of Medicine, Bayero University, Kano, Nigeria Reprint requests to> Dr. E. E. Nwokedi, Departments of Medical Microbiology and Parasitology, Aminu Kano Teaching Hospital, P. M. B. 3452, Kano, Nigeria. E-mail: [email protected] Key words: Syphilis, sexually Abstract transmitted diseases, Background: Sexually transmitted diseases are widespread in the developing seroprevalence countries and constitute a major public health problem in Sub-Saharan Africa. More recently, there has been a resurgence of syphilis. The aim of this study was to determine the seroprevalence rate of syphilis among newly recruited senior cadres of a Nigerian Security Agency. Method: Eight hundred and fifteen newly recruited men and women sent for serological test for syphilis (STS) in our laboratory were all screened accordingly using Rapid Plasma Reagin (RPR) test. All those that were positive wee confirmed using treponema pallidum haemagglutination (TPHA) test. Results: The seroprevalence rate of treponema pallidum infection was 4.0% (95%CI = 2.8% -5.6%). The rate was significantly higher among women 2 (8.0%) compare to men (3.4%) (X = 5.3 df = 1 P = 0.02). Considered by age, the highest seroprevalence of 6.7% was seen among oldest recruits (30- 39) years age group compared to 4.2% among the younger ones. This trend 2 was however, not statistically significant (X trend = 1.6 df =3 P = 0.20).
    [Show full text]
  • SYPHILIS HEALTH CHECK Rev. O, 04/15
    SYPHILIS HEALTH CHECK Rev. O, 04/15 CLIA Complexity: WAIVED for Fingerstick Whole Blood Specimens ONLY For in vitro diagnostic use only Rx Only A Certificate of Waiver is required to perform this test in a CLIA waived setting. To obtain a Certificate of Waiver, please contact your state health department. Additional CLIA waiver information is available at the Centers for Medicare and Medicaid website at www.cms.gov/CLIA or from your state health department. Failure to follow the instructions or modification to the test instructions will result in the test no longer meeting the requirements for waived category. INTENDED USE Syphilis Health Check is a qualitative rapid membrane immunochromatographic assay for the detection of Treponema pallidum (syphilis) antibodies in human whole blood, serum or plasma. This product can be used as an initial screening test or in conjunction with a nontreponemal laboratory test and clinical findings to aid in the diagnosis of syphilis infection. This test is not intended for use in screening blood or plasma donors. SUMMARY AND EXPLANATION Syphilis is a sexually transmitted disease (STD) caused by the spirochete organism Treponema pallidum (TP). As this organism cannot be cultured on artificial media, the diagnosis of syphilis depends on the correlation of clinical data with antibodies demonstrated by serological tests. Two types of antibody responses normally result: non-specific (anti-cardiolipin) (1,2) and specific (anti-treponemal). While non-specific antibodies occur in the majority of infected individuals, many other conditions can give rise to false positive results, yielding an overall specificity of about 50% in the general population(3).
    [Show full text]