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Nieuwenburg SA, Bruisten SM, Heijman T, Vermeulen W, van Dam AP, Schim van der Loeff MF, de Vries HJC. Use of Home-Based Self-Collected Dried Blood Spots to Test for Syphilis, Human Immunodeficiency Virus, Hepatitis C and B Virus Infections and Measuring Creatinine Concentration. Sex Transm Dis 2024; 51:283-288. [PMID: 38430511 DOI: 10.1097/olq.0000000000001941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2024]
Abstract
INTRODUCTION Home-based self-collected dried blood spot (DBS) sampling could simplify sexual health and preexposure prophylaxis care and reduce sexually transmitted infections (STIs) clinic visits for men who have sex with men (MSM). We compared the performance of DBS to venipuncture collected blood samples to test four STIs and creatinine concentration. METHODS We invited MSM clients of the Amsterdam STI clinic to participate. Routinely collected peripheral blood was tested for syphilis treponemal antibody, HIV (HIV Ag/Ab), HCV (antibodies), HBV (HBsAg) and creatinine concentration. Participants received a home kit for DBS sampling, a return envelope and a questionnaire to evaluate the acceptability, feasibility and usability of DBS, measured on 5-point Likert scales, 1 representing complete disagreement and 5 complete agreement. We assessed sensitivity and specificity of DBS versus peripheral blood-based testing. RESULTS In 2020 to 2021, we included 410 participants; 211 (51.5%) returned a completed DBS card, 117 (28.5%) returned a partially filled card and 82 (20.0%) did not return a card. The sensitivity for syphilis was 90.8% and the specificity 84.3%. For both HIV Ag/Ab and HBsAg, the sensitivity and specificity were 100.0%. The sensitivity for HCV antibody was 80.0%, and the specificity was 99.2%. The DBS creatinine concentration was a mean of 5.3 μmol/L higher than in venipuncture obtained plasma. Participants' median willingness to take a future DBS was 4 (interquartile range, 3-5). DISCUSSION Dried blood spot may be an acceptable method among MSM for STI testing and creatinine follow-up during preexposure prophylaxis use. However, collecting enough blood on DBS cards was a challenge, and sensitivities for syphilis and HCV serology were too low.
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Affiliation(s)
| | | | - T Heijman
- From the Department of Infectious Diseases, Public Health Service Amsterdam, Amsterdam, the Netherlands
| | - W Vermeulen
- From the Department of Infectious Diseases, Public Health Service Amsterdam, Amsterdam, the Netherlands
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Ma JQ, Ren YN, Wen SY, Dong AB, Xing WG, Jiang Y. Development and evaluation of serological screening based on one dried plasma spot for HIV, syphilis, and HCV. Virol J 2023; 20:293. [PMID: 38082318 PMCID: PMC10712157 DOI: 10.1186/s12985-023-02225-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 11/01/2023] [Indexed: 12/18/2023] Open
Abstract
BACKGROUND In the effort to prevent and control HIV/AIDS, China has established a national sentinel surveillance system. However, some sentinel sites face limitations in environmental resources and accessibility, prompting the exploration of alternative sample strategies. Dried plasma spots (DPS) samples are viewed as promising alternatives to traditional plasma samples due to their advantages, including sample stability, easy storage, and convenient transport. This study aims to develop a method for screening HIV, Treponema pallidum (TP), and Hepatitis C Virus (HCV) using DPS samples and assess their performance. METHODS Based on existing commercial assay kits, a detection method was established through the optimization of experimental parameters, including the amount of plasma on filter paper, the volume of elution solution applied to dried plasma spots, the size of dried plasma spots, elution solution volume, elution solution components, elution temperature, and elution time. A series of laboratory evaluation panels were constructed for laboratory assessments, including the laboratory basic panel, laboratory interference panel, and laboratory precision panel. Additionally, clinical samples were used for evaluation. RESULTS Optimal conditions for DPS sample extraction were: plasma volume, 100 µL; DPS size, whole spot; eluent volume, 500 µL; eluent, PBS with 1‰ Tween20; elution time, 2 h; elution temperature, room temperature. A total of 619 paired plasma/DPS samples were tested by both methods. The DPS-based ELISA method exhibited 100% sensitivity/specificity for HIV, 98.6%/100% for TP, and 99.6%/100% for HCV. Kappa values between the plasma samples and DPS samples were 100% for HIV, 99% for TP, and 100% for HCV. The DPS-based ELISA method failed to detect 1 HCV mono-infected sample and TP in 1 HIV/HCV/TP co-infected sample. For the HIV/HCV/TP co-infected sample, the S/CO in the plasma sample was 2.143 and in the DPS sample was 0.5. For HCV, the S/CO (sample OD/cut-off) was 3.049 in the plasma sample and 0.878 in the DPS sample. CONCLUSIONS A single DPS, following one-time standardized processing, can be used to detect HIV, HCV, and TP. Researching and establishing laboratory testing methods better suited for China's sentinel surveillance have significant practical applications in improving HIV testing in resource-constrained environments.
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Affiliation(s)
- Jie-Qiong Ma
- College of Basic Medical Sciences, Shanxi Medical University, Taiyuan, China.
- National HIV/HCV Reference Laboratory, National Center for AIDS/STD Control and Prevention, China CDC, Beijing, China.
| | - Ya-Nan Ren
- Fangshan Center for Disease Control and Prevention, Fangshan, Beijing, China
| | - Shi-Yuan Wen
- College of Basic Medical Sciences, Shanxi Medical University, Taiyuan, China
| | - Ao-Bo Dong
- Third Hospital of Baotou City, Baotou, 014040, China
| | - Wen-Ge Xing
- National HIV/HCV Reference Laboratory, National Center for AIDS/STD Control and Prevention, China CDC, Beijing, China
| | - Yan Jiang
- National HIV/HCV Reference Laboratory, National Center for AIDS/STD Control and Prevention, China CDC, Beijing, China.
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McAuliffe G, Gerber A, Chhibber A, Fisher M, Saxton P, Fisher T, Blakiston M, Forster R. Evaluating the sensitivity and specificity of dried blood spots for serological testing of HIV, syphilis, hepatitis B and C Elecsys assays on the Roche Cobas system. Pathology 2023; 55:1000-1003. [PMID: 37690864 DOI: 10.1016/j.pathol.2023.06.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 06/05/2023] [Accepted: 06/16/2023] [Indexed: 09/12/2023]
Abstract
This study was performed to validate a dried blood spot (DBS) method for the serological screening of HIV, syphilis, hepatitis B and C. It included 250 paired DBS and serum samples and 116 unpaired DBS samples from 366 unique patients from two laboratories between 8 October and 2 November 2021. As determined by original test request, these were tested using a DBS method for HIV Ag/Ab (n=216), anti-treponemal Ab (n=166), hepatitis B sAg (n=100), and hepatitis C Ab (n=100) Elecsys assays on the Roche Cobas automated platform. Using the manufacturer's (serum) cut-off for reactivity ('positivity'), the sensitivity and specificity of DBS testing compared with serum were: for HIV Ag/Ab 100% and 100%, for anti-treponemal Ab 68.3% and 100%, for hepatitis B sAg 95.9% and 100%, and for hepatitis C Ab 84.0% and 100%, respectively. Adjusting the assay cut-off using receiver operator curve analysis increased sensitivity of DBS testing for anti-treponemal Ab to 90.0%, hepatitis B sAg to 97.9% and hepatitis C Ab to 94.0% whilst maintaining specificity of 98.8%, 100% and 100%, respectively. With optimisation of assay cut-off, DBS can perform comparably with serum for serological testing for HIV, syphilis, hepatitis B and C and may be a valuable tool in increasing access to testing in New Zealand.
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Affiliation(s)
- Gary McAuliffe
- Labtests, Carbine Road, Mount Wellington, Auckland, New Zealand; LabPLUS, Te Whatu Ora, Te Toka Tumai, Grafton, Auckland, New Zealand.
| | - Adri Gerber
- Labtests, Carbine Road, Mount Wellington, Auckland, New Zealand
| | - Aakash Chhibber
- LabPLUS, Te Whatu Ora, Te Toka Tumai, Grafton, Auckland, New Zealand
| | | | - Peter Saxton
- University of Auckland, Grafton, Auckland, New Zealand
| | - Tony Fisher
- University of Auckland, Grafton, Auckland, New Zealand
| | - Matt Blakiston
- Labtests, Carbine Road, Mount Wellington, Auckland, New Zealand; LabPLUS, Te Whatu Ora, Te Toka Tumai, Grafton, Auckland, New Zealand
| | - Rose Forster
- Labtests, Carbine Road, Mount Wellington, Auckland, New Zealand; University of Auckland, Grafton, Auckland, New Zealand
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Vanroye F, Van den Bossche D, Vercauteren K. Prospective Laboratory Evaluation of the cobas Plasma Separation Card for HIV and Treponema pallidum Antibody Analysis. Sex Transm Dis 2023; 50:764-769. [PMID: 37824788 DOI: 10.1097/olq.0000000000001863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2023]
Abstract
BACKGROUND The cobas Plasma Separation Card (PSC; Roche Diagnostics) was developed for HIV viral load testing. This study evaluates the performance of HIV and Treponema pallidum (Tp) antibody (Ab) detection on PSCs as an alternative to dried blood spots (DBSs). METHODS EDTA whole blood samples were collected from HIV-positive (n = 100), HIV-negative (n = 50), Tp-positive (n = 100), and Tp-negative patients (n = 50) and spotted on DBS and PSC. Antibody detection performance was evaluated for HIV Ab using the Genscreen ULTRA HIV Ag-Ab test (Bio-Rad) and for Tp Ab using the Syphilis Total Ab test (Bio-Rad). Plasma was used as a reference specimen. RESULTS Receiver operating characteristic curve analysis for DBS and PSC generated areas under the curve (AUC + 95% confidence interval) of 0.985 (0.960-1.000) and 0.987 (0.973-1.000) for HIV Ab and 1.000 (1.000-1.000) and 0.996 (0.983-1.000) for Tp Ab, respectively. Receiver operating characteristic areas under the curve were not significantly different between DBS and PSC for HIV or TP Ab. At selected cutoff values rendering at least 99% sensitivity for HIV Ab detection, the specificity was 96% on DBS and 68% on PSC. For Tp Ab detection at 90% sensitivity, 100% specificity is reached on both DBS and PSC (exceeding the required 95%). However, the median quantitative HIV and Tp Ab signal of positive samples significantly decreased in PSC compared with DBS and plasma. CONCLUSIONS Although receiver operating characteristic analysis does not seem to indicate significant differences in performance between DBS and PSC, the significant reduction in quantitative Ab detection signal dictates card composition optimization before its use for HIV and Tp Ab detection can be advised.
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Affiliation(s)
- Fien Vanroye
- From the Clinical Reference Laboratory/AIDS Reference Laboratory
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Riegler AN, Larsen N, Amerson-Brown MH. Point-of-Care Testing for Sexually Transmitted Infections. Clin Lab Med 2023; 43:189-207. [PMID: 37169442 DOI: 10.1016/j.cll.2023.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Point-of-care testing for sexually transmitted infections is essential for controlling transmission and preventing sequelae in high-risk populations. Since the World Health Organization published the ASSURED criteria, point-of-care testing has improved for use in large population screening and rapid testing that prevents loss of clinical follow-up. Recent advancements have been advantageous for low-resource areas allowing testing at a minimal cost without reliable electricity or refrigeration. Point-of-care nucleic acid detection and amplification techniques are recommended, but are often inaccessible in low-resource areas. Future advancements in point-of-care diagnostic testing should focus on improving antibody-based assays, monitoring viral loads, and detecting antimicrobial resistance.
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Affiliation(s)
- Ashleigh N Riegler
- Department of Pathology, The University of Alabama at Birmingham, Marnix E. Heersink School of Medicine, 619 East 19th Street South, WP240J, Birmingham, AL 35249-7331, USA
| | - Natalie Larsen
- Department of Pathology, The University of Alabama at Birmingham, Marnix E. Heersink School of Medicine, 619 East 19th Street South, WP240J, Birmingham, AL 35249-7331, USA
| | - Megan H Amerson-Brown
- Department of Pathology, The University of Alabama at Birmingham, Marnix E. Heersink School of Medicine, 619 East 19th Street South, WP240J, Birmingham, AL 35249-7331, USA.
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McGrath N, Ngcobo N, Feng Z, Joseph P, Dladla P, Ngubane T, Hosegood V, Morton K, Van Rooyen H, Van Heerden A. Protocol: evaluation of an optimised couples-focused intervention to increase testing for HIV in rural KwaZulu-Natal, South Africa, the Igugu Lethu (‘Our treasure’) cohort study. BMC Public Health 2022; 22:1577. [PMID: 35986344 PMCID: PMC9389496 DOI: 10.1186/s12889-022-13894-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Accepted: 07/27/2022] [Indexed: 11/16/2022] Open
Abstract
Background Between 2012 and 2015, the Uthando Lwethu (UL) study demonstrated that a theory-based behavioural couples-focused intervention significantly increased participation in couples HIV testing and counselling (CHTC) among South African couples who had never previously tested for HIV together or mutually disclosed their HIV status, 42% compared to 12% of the control group at 9 months follow-up. Although effective, we were nonetheless concerned that in this high prevalence setting the majority (58%) of intervention couples chose not to test together. In response we optimised the UL intervention and in a new study, ‘Igugu Lethu’, we are evaluating the success of the optimised intervention in promoting CHTC. Methods One hundred eighty heterosexual couples, who have been in a relationship together for at least 6 months, are being recruited and offered the optimised couples-focused intervention. In the Igugu Lethu study, we have expanded the health screening visit offered to couples to include other health conditions in addition to CHTC. Enrolled couples who choose to schedule CHTC will also have the opportunity to undertake a random blood glucose test, blood pressure and BMI measurements, and self-sample for STI testing as part of their health screening. Individual surveys are administered at baseline, 4 weeks and 4 months follow-up. The proportion of couples who decide to test together for HIV will be compared to the results of the intervention arm in the UL study (historical controls). To facilitate this comparison, we will use the same recruitment and follow-up strategies in the same community as the previous UL study. Discussion By strengthening communication and functioning within the relationship, the Igugu Lethu study, like the previous UL study, aims to transform the motivation of individual partners from a focus on their own health to shared health as a couple. The Igugu Lethu study findings will answer whether the optimised couples-focused behavioural intervention and offering CHTC as part of a broader health screening for couples can increase uptake of CHTC by 40%, an outcome that would be highly desirable in populations with high HIV prevalence. Trial registration Retrospectively registered. ISRCTN Registry ISRCTN 46162564 Registered on 26th May 2022. Supplementary Information The online version contains supplementary material available at 10.1186/s12889-022-13894-3.
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At-home Specimen Self-Collection and Self-Testing for STI Screening Demand Accelerated by the COVID-19 Pandemic - A Review of Laboratory Implementation Issues. J Clin Microbiol 2021; 59:e0264620. [PMID: 34076475 DOI: 10.1128/jcm.02646-20] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The idea of specimen self-collection or self-STI testing is not new. In 2019, the World Health Organization (WHO) published the "WHO Consolidated Guideline on Self-Care Interventions for Health" as a first installment in a planned series for various diseases (8). The first document focused on "Sexual and Reproductive Health and Rights". Self-care including self-testing has the readily apparent benefits of privacy, confidentiality, speed, convenience, and access if the price is affordable. It is "people-centered" (9) and enables active participation in one's own health. It is also a health system approach as it can reduce burden on stretched systems with world-wide shortages in medical personnel or other barriers to health care access. Potential risks include: low specimen return rates, uncertain follow-up (linkage to care including treatment, repeat testing including test of cure, partner notification, counseling on risk reduction), unintended/unnecessary use (resulting in false positives with their own set of associated problems), incorrect use, lack of understanding of window periods (resulting in false negatives), lack of surveillance data generation, among other issues (9). The WHO systematically reviewed evidence for self-testing or specimen self-collection for GC, CT and syphilis, including US studies, and published a meta-analysis of available evidence (9). Programs offering self-collection of samples increased overall uptake of STI testing services (RR: 2.941, 95% CI 1.188 to 7.281) and case finding (RR: 2.166, 95% CI1.043 to 4.498), prior to the pandemic (9). U. S. laboratory research on the equivalence and/or superiority of self-collected versus provider-collected specimens for test sensitivity was reported by Gaydos et al (summarized or referenced in (10)). Based on this evidence, WHO issued a new recommendation in 2019 "Self-collection of samples for Neisseria gonorrhoeae and Chlamydia trachomatis should be made available as an additional approach to deliver STI testing services for individuals using STI testing services" (8). In addition, WHO issued a new and conditional recommendation: "Self-collection of samples for Treponema pallidum (syphilis) and Trichomonas vaginalis may be considered as an additional approach to deliver STI testing services for Individuals using STI testing services" (8). Thus, even before the COVID-19 pandemic, substantial expert agreement existed concerning benefits of this approach.
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8
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Amini F, Auma E, Hsia Y, Bilton S, Hall T, Ramkhelawon L, Heath PT, Le Doare K. Reliability of dried blood spot (DBS) cards in antibody measurement: A systematic review. PLoS One 2021; 16:e0248218. [PMID: 33720928 PMCID: PMC7959368 DOI: 10.1371/journal.pone.0248218] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 02/23/2021] [Indexed: 02/06/2023] Open
Abstract
Background Increasingly, vaccine efficacy studies are being recommended in low-and-middle-income countries (LMIC), yet often facilities are unavailable to take and store infant blood samples correctly. Dried blood spots (DBS), are useful for collecting blood from infants for diagnostic purposes, especially in low-income settings, as the amount of blood required is miniscule and no refrigeration is required. Little is known about their utility for antibody studies in children. This systematic review aims to investigate the correlation of antibody concentrations against infectious diseases in DBS in comparison to serum or plasma samples that might inform their use in vaccine clinical trials. Methods and findings We searched MEDLINE, Embase and the Cochrane library for relevant studies between January 1990 to October 2020 with no language restriction, using PRISMA guidelines, investigating the correlation between antibody concentrations in DBS and serum or plasma samples, and the effect of storage temperature on DBS diagnostic performance. We included 40 studies in this systematic review. The antibody concentration in DBS and serum/plasma samples reported a good pooled correlation, (r2 = 0.86 (ranged 0.43 to 1.00)). Ten studies described a decline of antibody after 28 days at room temperature compared to optimal storage at -20°C, where antibodies were stable for up to 200 days. There were only five studies of anti-bacterial antibodies. Conclusions There is a good correlation between antibody concentrations in DBS and serum/plasma samples, supporting the wider use of DBS in vaccine and sero-epidemiological studies, but there is limited data on anti-bacterial antibodies. The correct storage of DBS is critical and may be a consideration for longer term storage.
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Affiliation(s)
- Fahimah Amini
- Paediatric Infectious Disease Research Group, Institute for Infection and Immunity, St. George’s University of London, London, United Kingdom
- * E-mail:
| | - Erick Auma
- Department of Biology, University of Lyon, Université Claude Bernard Lyon, ENS de Lyon, CNRS, UMR, Lyon, France
| | - Yingfen Hsia
- Paediatric Infectious Disease Research Group, Institute for Infection and Immunity, St. George’s University of London, London, United Kingdom
- School of Pharmacy, Queen’s University Belfast, Belfast, United Kingdom
| | - Sam Bilton
- St Georges University Hospitals NHS Foundation Trust, Tooting, London, United Kingdom
| | - Tom Hall
- Paediatric Infectious Disease Research Group, Institute for Infection and Immunity, St. George’s University of London, London, United Kingdom
| | - Laxmee Ramkhelawon
- Paediatric Infectious Disease Research Group, Institute for Infection and Immunity, St. George’s University of London, London, United Kingdom
| | - Paul T. Heath
- Paediatric Infectious Disease Research Group, Institute for Infection and Immunity, St. George’s University of London, London, United Kingdom
- St Georges University Hospitals NHS Foundation Trust, Tooting, London, United Kingdom
| | - Kirsty Le Doare
- Paediatric Infectious Disease Research Group, Institute for Infection and Immunity, St. George’s University of London, London, United Kingdom
- St Georges University Hospitals NHS Foundation Trust, Tooting, London, United Kingdom
- Pathogen Immunology Group, Public Health England, Porton Down, United Kingdom
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Ma J, Ren Y, He L, He X, Xing W, Jiang Y. An efficient method for simultaneously screening for HIV, syphilis, and HCV based on one dried blood spot sample. Antiviral Res 2020; 181:104775. [PMID: 32246944 DOI: 10.1016/j.antiviral.2020.104775] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 02/23/2020] [Accepted: 03/13/2020] [Indexed: 12/29/2022]
Abstract
OBJECTIVE The aim of this study was to optimize the parameters of a dried blood spot (DBS)-based ELISA method to simultaneously screen for anti-HIV, anti-hepatitis C virus (HCV) and anti-treponema pallidum (TP) antibodies, and investigate the assay performance. METHODS Experiments were performed to establish optimized parameters for a DBS-based ELISA method to simultaneously screen for anti-HIV, anti-HCV, and anti-TP antibodies. Then, 429 paired plasma and DBS samples were collected to evaluate the performance of the assay with optimized parameters. Plasma test results were used as the reference standard. RESULTS The optimized assay conditions were: blood volume, 70-100 μL; DBS size, whole spot; eluent volume, 500 μL; eluent, PBS with 1‰ Tween20; elution time, 4 h; elution temperature, room temperature. The overall prevalence of HIV, HCV, and TP was 6.06% (95% confidence interval [CI]: 4.07-8.87%), 27.74% (95% CI: 23.60-32.28%), and 14.92% (95% CI: 11.75-18.73%). The clinical sensitivity of the assay for anti-HIV, anti-HCV, and anti-TP antibodies was 88.46%, 98.32%, and 92.19%, respectively. The assay was 100% specificity for each analyte. The assay positive predictive value for each analyte was 100%, and the negative predictive values were >98%. Of the 429 samples, 9 DBS results were different than the plasma results; in these samples the plasma signal-to-cutoff rations were low (range, 1.40-7.81). CONCLUSION The DBS-based ELISA method demonstrated good performance for simultaneously screening for anti-HIV, anti-HCV, and anti-TP antibodies. DBS samples are a promising method to screen for HIV, HCV, and TP infections. IMPORTANCE DBS samples are a promising alternative to plasma samples, with the advantages of good sample stability, smaller blood volume, simpler storage, and easier transport. DBS sample testing is used for the diagnosis of a wide variety of pathogens, including HIV, hepatitis B virus (HBV), and hepatitis C virus (HCV). The performance of DBS samples for the serological diagnosis of HIV, HCV, and Treponema pallidum (TP) has been demonstrated to be good in many studies, and therefore DBS is regarded as an ideal choice to screen for HIV, HCV, and TP infections, especially in difficult-access or resource-limited settings. There is no generally accepted procedure for sample collection and processing of DBS samples and there are few studies on simultaneous detection of anti-HIV, anti-HCV and anti-TP using a single DBS.
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Affiliation(s)
- Jieqiong Ma
- National HIV/HCV Reference Laboratory, National Center for AIDS/STD Control and Prevention, China CDC, Beijing, China
| | - Yanan Ren
- National HIV/HCV Reference Laboratory, National Center for AIDS/STD Control and Prevention, China CDC, Beijing, China
| | - Lin He
- National HIV/HCV Reference Laboratory, National Center for AIDS/STD Control and Prevention, China CDC, Beijing, China
| | - Xiaoxia He
- National HIV/HCV Reference Laboratory, National Center for AIDS/STD Control and Prevention, China CDC, Beijing, China
| | - Wenge Xing
- National HIV/HCV Reference Laboratory, National Center for AIDS/STD Control and Prevention, China CDC, Beijing, China
| | - Yan Jiang
- National HIV/HCV Reference Laboratory, National Center for AIDS/STD Control and Prevention, China CDC, Beijing, China.
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Handley BL, Butcher R, Taoaba R, Roberts CH, Cama A, Müeller A, Solomon AW, Tekeraoi R, Marks M. Absence of Serological Evidence of Exposure to Treponema pallidum among Children Suggests Yaws Is No Longer Endemic in Kiribati. Am J Trop Med Hyg 2020; 100:940-942. [PMID: 30719964 PMCID: PMC6447131 DOI: 10.4269/ajtmh.18-0799] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Yaws is a neglected tropical disease targeted for eradication by 2020. Kiribati, a Pacific Island nation, was previously endemic for yaws but lacks recent data from which its current endemicity status could be determined. This study tested antibody responses to Treponema pallidum to determine if transmission of yaws is taking place among children in Kiribati. Using a commercially available T. pallidum particle agglutination kit (Serodia®, Fujirebio Inc., Tokyo, Japan), we tested dried blood spots, collected during population-based trachoma prevalence surveys on Tarawa Atoll and Kiritimati Island, for long-lived treponemal antibodies. Dried blood spots from 1,420 children aged 1-9 years were tested. Only two were positive, suggesting T. pallidum is not being widely transmitted among children in the settings sampled. These data require support from additional surveys to demonstrate the absence of clinical signs of disease and molecular evidence of infection, to confirm that yaws is no longer endemic in Kiribati.
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Affiliation(s)
- Becca L Handley
- Clinical Research Department, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Robert Butcher
- Clinical Research Department, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Raebwebwe Taoaba
- Eye Department, Ministry of Health and Medical Services, South Tarawa, Kiribati
| | - Chrissy H Roberts
- Clinical Research Department, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Anasaini Cama
- The International Agency for the Prevention of Blindness, Melbourne, Australia.,The Fred Hollows Foundation, Sydney, Australia
| | - Andreas Müeller
- Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland.,Centre for Eye Research Australia, University of Melbourne, Melbourne, Australia
| | - Anthony W Solomon
- Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland.,Clinical Research Department, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Rabebe Tekeraoi
- Eye Department, Ministry of Health and Medical Services, South Tarawa, Kiribati
| | - Michael Marks
- Clinical Research Department, London School of Hygiene & Tropical Medicine, London, United Kingdom
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Kularatne R. Use of rapid point-of-care diagnostic tests for the elimination of congenital syphilis: what is the evidence? S Afr J Infect Dis 2018. [DOI: 10.1080/23120053.2018.1512550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Affiliation(s)
- Ranmini Kularatne
- Centre for HIV & STI, National Institute for Communicable Diseases, Johannesburg, South Africa
- Department of Clinical Microbiology & Infectious Diseases, University of the Witwatersrand, Johannesburg, South Africa
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12
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van Loo IHM, Dukers-Muijrers NHTM, Heuts R, van der Sande MAB, Hoebe CJPA. Screening for HIV, hepatitis B and syphilis on dried blood spots: A promising method to better reach hidden high-risk populations with self-collected sampling. PLoS One 2017; 12:e0186722. [PMID: 29053737 PMCID: PMC5650165 DOI: 10.1371/journal.pone.0186722] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 10/08/2017] [Indexed: 01/28/2023] Open
Abstract
Introduction Many people at high risk for sexually transmitted infections (STIs), e.g., men who have sex with men (MSM), are not optimally reached by current sexual health care systems with testing. To facilitate testing by home-based sampling or sampling in outreach setting we evaluated dried blood spots (DBS), a method for self-collected blood sampling for serological screening of HIV, hepatitis B (HBV) and syphilis. The aims of this study were to assess the acceptability and feasibility of self-collected DBS and to compare the test results for screening of HIV, HBV and syphilis from DBS with blood drawn by venous puncture. Methods DBS were collected from men who have sex with men (MSM), visiting the STI clinic of the public health service South Limburg (n = 183) and HIV positive and HBV positive patients (n = 34), visiting the outpatient clinics of the Maastricht University Medical Centre in the period January 2012–April 2015. The 93 first participating MSM visiting the STI clinic were asked to fill in a questionnaire about the feasibility and acceptability about self-collection of DBS in a setting without going to a health care facility and were asked to collect the DBS themselves. Serological screening tests for HIV (HIV combi PT, Roche), HBV (HBsAg, Roche) and syphilis (Treponema pallidum Ig, Biokit 3.0) were performed on DBS and on blood drawn by venous puncture, which was routinely taken for screening. Results In total 217 participants were included in the study with a median age of 40 years (range between 17–80). Of MSM 84% agreed that it was clear and easy to do the finger-prick, while 53% agreed that it was clear and easy to apply the blood onto the DBS card. Also, 80% of MSM would use the bloodspot test again. In 91% (198) of DBS, sufficient material was collected to perform the three tests. No difference was observed in DBS quality between self-collected DBS and health care worker collected DBS. For HIV (n = 195 DBS-serum pairs) sensitivity and specificity were 100%. For HBV the sensitivity for HBsAg (n = 202) was 90% and specificity was 99%. For syphilis (n = 191) the sensitivity of the DBS was 93% with a specificity of 99%. Analysis of the DBS of HIV positive participants (n = 38) did show similar test performance for HBV and syphilis as in HIV negatives. Conclusion DBS is an acceptable self-sampling method for MSM, as there was no difference in DBS quality in self-collected and health care worker collected DBS. Test performance, i.e., its high sensitivity (>90%) and specificity (>99%) measures show that DBS is a valid alternative for venous blood puncture. Especially when DBS is combined with home-collected sampling for Chlamydia trachomatis and Neisseria gonorrhoeae, complete STI screening can be done in outreach setting and/or home-collected sampling in MSM.
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Affiliation(s)
- Inge H. M. van Loo
- Department of Medical Microbiology, Maastricht University Medical Centre, Maastricht, The Netherlands
- Care and Public Health Research Institute (CAPHRI), Maastricht University, Maastricht, The Netherlands
- * E-mail:
| | - Nicole H. T. M. Dukers-Muijrers
- Department for Sexual Health, Infectious Diseases and Environmental Health, Public Health Service South Limburg, Geleen, The Netherlands
| | - Rosalie Heuts
- Department of Medical Microbiology, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Marianne A. B. van der Sande
- Centre Infectious Disease Control, National Institute for Public Health and the Environment, Bilthoven, The Netherlands
- Julius Center, University Medical Center Utrecht, Utrecht, The Netherlands
- Institute of Tropical Medicine, Antwerp, Belgium
| | - Christian J. P. A. Hoebe
- Department of Medical Microbiology, Maastricht University Medical Centre, Maastricht, The Netherlands
- Care and Public Health Research Institute (CAPHRI), Maastricht University, Maastricht, The Netherlands
- Department for Sexual Health, Infectious Diseases and Environmental Health, Public Health Service South Limburg, Geleen, The Netherlands
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Abstract
Treponema pallidum subspecies pallidum (T. pallidum) causes syphilis via sexual exposure or via vertical transmission during pregnancy. T. pallidum is renowned for its invasiveness and immune-evasiveness; its clinical manifestations result from local inflammatory responses to replicating spirochaetes and often imitate those of other diseases. The spirochaete has a long latent period during which individuals have no signs or symptoms but can remain infectious. Despite the availability of simple diagnostic tests and the effectiveness of treatment with a single dose of long-acting penicillin, syphilis is re-emerging as a global public health problem, particularly among men who have sex with men (MSM) in high-income and middle-income countries. Syphilis also causes several hundred thousand stillbirths and neonatal deaths every year in developing nations. Although several low-income countries have achieved WHO targets for the elimination of congenital syphilis, an alarming increase in the prevalence of syphilis in HIV-infected MSM serves as a strong reminder of the tenacity of T. pallidum as a pathogen. Strong advocacy and community involvement are needed to ensure that syphilis is given a high priority on the global health agenda. More investment is needed in research on the interaction between HIV and syphilis in MSM as well as into improved diagnostics, a better test of cure, intensified public health measures and, ultimately, a vaccine.
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Affiliation(s)
- Rosanna W Peeling
- London School of Hygiene &Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - David Mabey
- London School of Hygiene &Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Mary L Kamb
- Division of STD Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Xiang-Sheng Chen
- National Center for STD Control, Chinese Academy of Medical Sciences and Peking Union Medical College Institute of Dermatology, Nanjing, China
| | - Justin D Radolf
- Department of Medicine, UConn Health, Farmington, Connecticut, USA
| | - Adele S Benzaken
- Department of Surveillance, Prevention and Control of STI, HIV/AIDS and Viral Hepatitis, Ministry of Health, Brasília, Brazil
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Marks M, Mabey DC. The introduction of syphilis point of care tests in resource limited settings. Expert Rev Mol Diagn 2017; 17:321-325. [PMID: 28266230 DOI: 10.1080/14737159.2017.1303379] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
INTRODUCTION Syphilis remains an important and preventable cause of stillbirth and neonatal mortality. About 1 million women with active syphilis become pregnant each year. Without treatment, 25% of them will deliver a stillborn baby and 33% a low birth weight baby with an increased chance of dying in the first month of life. Adverse pregnancy outcomes due to syphilis can be prevented by screening pregnant women, and treating those who test positive with a single dose of penicillin before 28 weeks' gestation. Areas covered: This manuscript covers the impact of syphilis on pregnancy outcome, the diagnosis of syphilis, with a special focus on point of care (POC) tests, and challenges to the introduction of POC tests, and their potential impact on the control and prevention of syphilis in resource limited settings. Expert commentary: POC tests for syphilis are available which meet the ASSURED criteria, and could make syphilis screening accessible to all women anywhere in the world who attend an antenatal clinic. High quality dual POC tests for HIV and syphilis could ensure that well-funded programmes for the prevention of mother to child transmission of HIV can contribute towards increased coverage of antenatal syphilis screening, and prevent more than 300,000 adverse pregnancy outcomes due to syphilis annually. Alongside investment to increase availability of syphilis POC tests, operational research is needed to understand how best to improve screening of pregnant women and to translate test availability into improved pregnancy outcomes.
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Affiliation(s)
- Michael Marks
- a London School of Hygiene & Tropical Medicine , Keppel Street, London , WC1E 7HT
| | - David Cw Mabey
- a London School of Hygiene & Tropical Medicine , Keppel Street, London , WC1E 7HT
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15
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Migchelsen SJ, Martin DL, Southisombath K, Turyaguma P, Heggen A, Rubangakene PP, Joof H, Makalo P, Cooley G, Gwyn S, Solomon AW, Holland MJ, Courtright P, Willis R, Alexander NDE, Mabey DCW, Roberts CH. Defining Seropositivity Thresholds for Use in Trachoma Elimination Studies. PLoS Negl Trop Dis 2017; 11:e0005230. [PMID: 28099433 PMCID: PMC5242428 DOI: 10.1371/journal.pntd.0005230] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 12/05/2016] [Indexed: 11/13/2022] Open
Abstract
Background Efforts are underway to eliminate trachoma as a public health problem by 2020. Programmatic guidelines are based on clinical signs that correlate poorly with Chlamydia trachomatis (Ct) infection in post-treatment and low-endemicity settings. Age-specific seroprevalence of anti Ct Pgp3 antibodies has been proposed as an alternative indicator of the need for intervention. To standardise the use of these tools, it is necessary to develop an analytical approach that performs reproducibly both within and between studies. Methodology Dried blood spots were collected in 2014 from children aged 1–9 years in Laos (n = 952) and Uganda (n = 2700) and from people aged 1–90 years in The Gambia (n = 1868). Anti-Pgp3 antibodies were detected by ELISA. A number of visual and statistical analytical approaches for defining serological status were compared. Principal Findings Seroprevalence was estimated at 11.3% (Laos), 13.4% (Uganda) and 29.3% (The Gambia) by visual inspection of the inflection point. The expectation-maximisation algorithm estimated seroprevalence at 10.4% (Laos), 24.3% (Uganda) and 29.3% (The Gambia). Finite mixture model estimates were 15.6% (Laos), 17.1% (Uganda) and 26.2% (The Gambia). Receiver operating characteristic (ROC) curve analysis using a threshold calibrated against external reference specimens estimated the seroprevalence at 6.7% (Laos), 6.8% (Uganda) and 20.9% (The Gambia) when the threshold was set to optimise Youden’s J index. The ROC curve analysis was found to estimate seroprevalence at lower levels than estimates based on thresholds established using internal reference data. Thresholds defined using internal reference threshold methods did not vary substantially between population samples. Conclusions Internally calibrated approaches to threshold specification are reproducible and consistent and thus have advantages over methods that require external calibrators. We propose that future serological analyses in trachoma use a finite mixture model or expectation-maximisation algorithm as a means of setting the threshold for ELISA data. This will facilitate standardisation and harmonisation between studies and eliminate the need to establish and maintain a global calibration standard. Trachoma is caused by the bacterium Chlamydia trachomatis (Ct). Individuals who have previously been infected with Ct carry specific antibodies in their blood. Recent studies have suggested that these antibodies may be a good way to estimate the intensity of transmission of this bacterium in a population. Among people who do have antibodies (seropositives) there is variation in the amount that is detectable in their blood. Some people have such low levels that differentiating them from those who don’t have antibodies (seronegatives) is challenging. We used a new test for Ct antibodies on blood specimens from three countries. Our test worked extremely well, giving reproducible results when we tested the same samples multiple times. We compared four different methods for setting the position of the threshold line between seronegatives and seropositives. The estimated transmission intensity in each country varied depending on the threshold method used, but two methods that used statistical modelling algorithms to define the two groups performed consistently across all three countries’ samples. We recommend that future studies should consider adopting the statistical modelling approaches, as they are objective tests that require no reference material and allow for standardisation between studies.
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Affiliation(s)
- Stephanie J. Migchelsen
- Clinical Research Department, London School of Hygiene & Tropical Medicine, London, United Kingdom
- * E-mail:
| | - Diana L. Martin
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | | | - Patrick Turyaguma
- Trachoma Control Programme, Ugandan Ministry of Health, Kampala, Uganda
| | - Anne Heggen
- NTD Support Centre, Decatur, Georgia, United States of America
| | | | - Hassan Joof
- Medical Research Council Unit The Gambia, Fajara, The Gambia
| | - Pateh Makalo
- Medical Research Council Unit The Gambia, Fajara, The Gambia
| | - Gretchen Cooley
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Sarah Gwyn
- IHRC, Inc., Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Anthony W. Solomon
- Clinical Research Department, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland
| | - Martin J. Holland
- Clinical Research Department, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Paul Courtright
- Kilimanjaro Centre for Community Ophthalmology, University Cape Town, Cape Town, South Africa
| | - Rebecca Willis
- International Trachoma Initiative, The Task Force for Global Health, Decatur, Georgia, United States of America
| | - Neal D. E. Alexander
- MRC Tropical Epidemiology Group, Infectious Disease Epidemiology Department, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - David C. W. Mabey
- Clinical Research Department, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Chrissy h. Roberts
- Clinical Research Department, London School of Hygiene & Tropical Medicine, London, United Kingdom
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Cocks N, Rainima-Qaniuci M, Yalen C, Macleod C, Nakolinivalu A, Migchelsen S, Roberts CH, Butcher R, Kama M, Mabey D, Marks M. Community seroprevalence survey for yaws and trachoma in the Western Division of Fiji. Trans R Soc Trop Med Hyg 2016; 110:582-587. [PMID: 27852877 PMCID: PMC5155547 DOI: 10.1093/trstmh/trw069] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 10/16/2016] [Accepted: 10/20/2016] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Both yaws and trachoma are endemic in several countries in the Pacific. In co-endemic countries there may be potential synergies between both control programmes. METHODS We undertook a cluster randomised trachoma and yaws seroprevalence survey of children in the Western Division of Fiji. Children were examined for skin lesions consistent with active yaws. A dried blood spot was collected which was tested using the Treponema pallidum particle agglutination (TPPA) test and an ELISA to detect antibodies against Pgp3. RESULTS A total of 607 children from 305 households across 23 villages were recruited into the survey. On skin examination, no child had clinical evidence of yaws, and the TPPA assay was negative in all children (0%, 95% CI 0.0-0.6). The seroprevalence of Pgp3 antibodies was 20.9% (95% CI 17.8-24.6%). DISCUSSION In this study there was neither clinical nor serological evidence that transmission of yaws was ongoing. The Pgp3 seroprevalence pattern was consistent with either low level transmission of ocular Chlamydia trachomatis or exposure to C. trachomatis in the birth canal which is consistent with a survey conducted in the same region in 2013. These data suggest neither yaws nor ocular chlamydia infection are a significant public health problem in the Western Division of Fiji.
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Affiliation(s)
- Naomi Cocks
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | | | - Chelsea Yalen
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Colin Macleod
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | | | - Stephanie Migchelsen
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Chrissy H Roberts
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Robert Butcher
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Mike Kama
- Fiji Centre for Communicable Disease, Ministry of Health, Suva, Fiji
| | - David Mabey
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
- Hospital for Tropical Diseases, University College London Hospitals NHS Trust, London WC1E 6JB, UK
| | - Michael Marks
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
- Hospital for Tropical Diseases, University College London Hospitals NHS Trust, London WC1E 6JB, UK
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17
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Marks M, Sokana O, Nachamkin E, Puiahi E, Kilua G, Pillay A, Bottomley C, Solomon AW, Mabey DC. Prevalence of Active and Latent Yaws in the Solomon Islands 18 Months after Azithromycin Mass Drug Administration for Trachoma. PLoS Negl Trop Dis 2016; 10:e0004927. [PMID: 27551787 PMCID: PMC4994934 DOI: 10.1371/journal.pntd.0004927] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 07/25/2016] [Indexed: 11/30/2022] Open
Abstract
Introduction Both yaws and trachoma are endemic in the Pacific. Mass treatment with azithromycin is the mainstay of the WHO strategy for both the eradication of yaws and the elimination of trachoma as a public health problem, but the dose recommended for trachoma is lower than that for yaws. In countries where both diseases are endemic, there is a potential for synergy between yaws and trachoma control programs if mass treatment with the lower dose of azithromycin was shown to be effective for the treatment of yaws. In an earlier study, we demonstrated a profound reduction in the clinical and serological prevalence of yaws following a single round of mass treatment with azithromycin 20 mg/kg undertaken for the purposes of trachoma elimination. Methods This survey was conducted 18 months following a single round of azithromycin mass treatment in the same communities in which we had conducted our previous six-month follow-up survey. We examined children aged 1–14 years and took blood and lesion samples for yaws diagnosis using the Treponema pallidum particle agglutination assay (TPPA) and the non-treponemal Rapid Plasma Reagin (RPR) test. Results A total of 1,284 children were enrolled in the study. Amongst children aged 5–14 years, 223 had a positive TPPA (27.5%, 95% CI 13.6–47.7%). The TPPA seroprevalence amongst this age group did not differ significantly from either our pre-mass treatment survey or our initial follow-up survey. Thirty-five children had positive TPPA and positive RPR (4.3%, 95% CI 2.1–8.7%), and this did not differ significantly from our initial post-mass drug administration (MDA) follow-up survey (4.3% versus 3.5%, p = 0.43) but remained significantly lower than our initial pre-MDA survey (4.3% vs 21.7%, p <0.0001). Village-level MDA coverage was strongly associated with dual-seropositivity (p = 0.005). Amongst children aged 1–4 years, 16 had a positive TPPA (3.5%, 95% CI 1.6–7.1%). This did not differ significantly from the seroprevalence in this age group that had been predicted based on our previous surveys (3.5% vs 5%, p = 0.11). Fourteen children (1.1%) were considered to have a skin lesion clinically consistent with yaws, but none of these individuals was seropositive for yaws. Of nine cases where a swab could be collected for PCR, all were negative for Treponema pallidum subsp. pertenue DNA. Discussion In this study we have shown that the benefit of a single round of mass treatment with azithromycin 20mg/kg appears to extend to 18 months without any further intervention. The lack of a significant change in seroprevalence from 6 to 18 months after mass treatment might suggest that interventions could be spaced at yearly intervals without a significant loss of impact, and that this might facilitate integration of yaws eradication with other neglected tropical disease (NTD) control programmes. MDA coverage above 90% was associated with significantly better outcomes than coverages lower than this threshold, and strategies to improve coverage at all stages of yaws eradication efforts should be investigated. Yaws is a neglected tropical disease caused by a bacterium closely related to the agent of syphilis. Mass treatment is recommended by WHO for the control of both yaws and the blinding eye disease trachoma, but the dose used for trachoma is lower (20 mg/kg versus 30 mg/kg). We have previously shown that a single round of mass treatment with azithromycin for trachoma had a significant impact on the number of cases of yaws in a community, suggesting that the lower dose of azithromycin might be effective for yaws and that trachoma and yaws programmes in the Pacific might be integrated. We repeated our survey 18 months following the initial round of mass treatment to see if the benefit seen at 6 months had persisted. In this study, the number of yaws cases remained significantly lower than before mass treatment even without any additional public health interventions taking place in the 18 months between MDA and this follow-up. This might suggest that annual mass treatment could be used rather than the current recommendation of six monthly treatment. An annual treatment strategy might facilitate integrating yaws eradication efforts with other NTD control programmes.
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Affiliation(s)
- Michael Marks
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
- The Hospital for Tropical Diseases, London, United Kingdom
- * E-mail:
| | - Oliver Sokana
- Ministry of Health and Medical Services, Honiara, Solomon Islands
| | - Eli Nachamkin
- Molecular Diagnostics & Typing Laboratory, Laboratory Reference & Research Branch, Division of STD Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Elliot Puiahi
- Ministry of Health and Medical Services, Honiara, Solomon Islands
| | - Georgina Kilua
- World Health Organization, Western Pacific Region Office, Honiara, Solomon Islands
| | - Allan Pillay
- Molecular Diagnostics & Typing Laboratory, Laboratory Reference & Research Branch, Division of STD Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Christian Bottomley
- Department of Infectious Diseases Epidemiology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Anthony W. Solomon
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
- The Hospital for Tropical Diseases, London, United Kingdom
| | - David C. Mabey
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
- The Hospital for Tropical Diseases, London, United Kingdom
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Knauf S, Dahlmann F, Batamuzi EK, Frischmann S, Liu H. Validation of serological tests for the detection of antibodies against Treponema pallidum in nonhuman primates. PLoS Negl Trop Dis 2015; 9:e0003637. [PMID: 25803295 PMCID: PMC4372418 DOI: 10.1371/journal.pntd.0003637] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 02/22/2015] [Indexed: 01/06/2023] Open
Abstract
There is evidence to suggest that the yaws bacterium (Treponema pallidum ssp. pertenue) may exist in non-human primate populations residing in regions where yaws is endemic in humans. Especially in light of the fact that the World Health Organizaiton (WHO) recently launched its second yaws eradication campaign, there is a considerable need for reliable tools to identify treponemal infection in our closest relatives, African monkeys and great apes. It was hypothesized that commercially available serological tests detect simian anti-T. pallidum antibody in serum samples of baboons, with comparable sensitivity and specificity to their results on human sera. Test performances of five different treponemal tests (TTs) and two non-treponemal tests (NTTs) were evaluated using serum samples of 57 naturally T. pallidum-infected olive baboons (Papio anubis) from Lake Manyara National Park in Tanzania. The T. pallidum particle agglutination assay (TP-PA) was used as a gold standard for comparison. In addition, the overall infection status of the animals was used to further validate test performances. For most accurate results, only samples that originated from baboons of known infection status, as verified in a previous study by clinical inspection, PCR and immunohistochemistry, were included. All tests, TTs and NTTs, used in this study were able to reliably detect antibodies against T. pallidum in serum samples of infected baboons. The sensitivity of TTs ranged from 97.7-100%, while specificity was between 88.0-100.0%. The two NTTs detected anti-lipoidal antibodies in serum samples of infected baboons with a sensitivity of 83.3% whereas specificity was 100%. For screening purposes, the TT Espline TP provided the highest sensitivity and specificity and at the same time provided the most suitable format for use in the field. The enzyme immune assay Mastblot TP (IgG), however, could be considered as a confirmatory test.
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Affiliation(s)
- Sascha Knauf
- German Primate Center, Pathology Unit, Work Group Neglected Tropical Diseases, Göttingen, Germany
- * E-mail:
| | - Franziska Dahlmann
- German Primate Center, Pathology Unit, Work Group Neglected Tropical Diseases, Göttingen, Germany
| | - Emmanuel K. Batamuzi
- Sokoine University of Agriculture, Faculty of Veterinary Medicine, Department of Surgery and Theriogenology, Morogoro, Tanzania
| | | | - Hsi Liu
- National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Centers for Diseases Control and Prevention, Atlanta, Georgia, United States of America
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Wood M, Ellks R, Grobicki M. Outreach sexual infection screening and postal tests in men who have sex with men: are they comparable to clinic screening? Int J STD AIDS 2014; 26:428-31. [DOI: 10.1177/0956462414539668] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2014] [Accepted: 05/19/2014] [Indexed: 11/16/2022]
Abstract
Men who have sex with men (MSM) have higher rates of poor sexual health. The National Institute for Health and Care Excellence has produced guidance on increasing the uptake of HIV testing to reduce undiagnosed infection in MSM. We report the results of a pilot outreach sexually transmitted infection service using nurse-delivered screening and self-sampled postal testing at a sex on premises venue with comparison made against a sexual health clinic service. Thirty men were included in each group. Users of the nurse-delivered and postal services were older (nurse service median age 57.5 years vs. postal kit service 47 years vs. clinic 35.5 years, p ≤ 0.001). Outreach groups were less likely to have undertaken sexually transmitted infection testing previously than the clinic group (53.3% and 60% vs. 93.3%, p ≤ 0.001). Chlamydia trachomatis and Neisseria gonorrhoeae testing uptake was comparable across groups (nurse outreach 86.6%, ‘do it yourself’ postal kit 100% vs. clinic 100%, p = 0.032), but uptake for blood tests was lower in the postal kit group (nurse outreach 83.3%, postal kit 53.3% vs. clinic 100%, p ≤ 0.001). No significant difference in active sexually transmitted infection positivity across the groups was observed. This combination outreach screening approach is effective in targeting MSM who use sex on premises venues.
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Affiliation(s)
- Martyn Wood
- Centre for Sexual Health and Contraception, Mid-Cheshire Hospitals NHS Foundation Trust, Leighton Hospital, Crewe, UK
| | - Rachael Ellks
- Centre for Sexual Health and Contraception, Mid-Cheshire Hospitals NHS Foundation Trust, Leighton Hospital, Crewe, UK
| | - Moira Grobicki
- Centre for Sexual Health and Contraception, Mid-Cheshire Hospitals NHS Foundation Trust, Leighton Hospital, Crewe, UK
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Kay NS, Peeling RW, Mabey DC. State of the art syphilis diagnostics: rapid point-of-care tests. Expert Rev Anti Infect Ther 2013; 12:63-73. [PMID: 24308715 DOI: 10.1586/14787210.2014.860356] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Syphilis remains an important and entirely preventable cause of stillbirth and neonatal mortality. More than 1 million women with active syphilis become pregnant each year. Without treatment, 25% of them will deliver a stillborn baby, 33% will deliver a live low-birth weight baby with an increased chance of dying in the first month of life. Adverse pregnancy outcomes due to syphilis can be prevented by screening pregnant women, and treating those who test positive with a single dose of penicillin before 28 weeks gestation. Until recently access to screening in low- and middle-income countries has been limited, since screening tests have been laboratory based, requiring equipment, electricity and trained laboratory staff. Now a number of rapid, cheap, simple and accurate screening tests are available and can give a result in 15-20 min, enabling those who require treatment to be treated at their first visit.
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Affiliation(s)
- Natasha S Kay
- St Mary's Hospital, Praed Street, W2 1NY, London, UK
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Smit PW, Mabey D, van der Vlis T, Korporaal H, Mngara J, Changalucha J, Todd J, Peeling RW. The implementation of an external quality assurance method for point- of- care tests for HIV and syphilis in Tanzania. BMC Infect Dis 2013; 13:530. [PMID: 24206624 PMCID: PMC3830510 DOI: 10.1186/1471-2334-13-530] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Accepted: 11/05/2013] [Indexed: 12/02/2022] Open
Abstract
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.
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Affiliation(s)
- Pieter W Smit
- Leiden Cytology and Pathology Laboratory, Leiden, Netherlands.
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Smit PW, Mabey D, Changalucha J, Mngara J, Clark B, Andreasen A, Todd J, Urassa M, Zaba B, Peeling RW. The trade-off between accuracy and accessibility of syphilis screening assays. PLoS One 2013; 8:e75327. [PMID: 24066175 PMCID: PMC3774815 DOI: 10.1371/journal.pone.0075327] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Accepted: 08/12/2013] [Indexed: 11/24/2022] Open
Abstract
The availability of rapid and sensitive methods to diagnose syphilis facilitates screening of pregnant women, which is one of the most cost-effective health interventions available. We have evaluated two screening methods in Tanzania: an enzyme immunoassay (EIA), and a point-of-care test (POCT). We evaluated the performance of each test against the Treponema pallidum particle agglutination assay (TPPA) as the reference method, and the accessibility of testing in a rural district of Tanzania. The POCT was performed in the clinic on whole blood, while the other assays were performed on plasma in the laboratory. Samples were also tested by the rapid plasma Reagin (RPR) test. With TPPA as reference assay, the sensitivity and specificity of EIA were 95.3% and 97.8%, and of the POCT were 59.6% and 99.4% respectively. The sensitivity of the POCT and EIA for active syphilis cases (TPPA positive and RPR titer ≥ 1/8) were 82% and 100% respectively. Only 15% of antenatal clinic attenders in this district visited a health facility with a laboratory capable of performing the EIA. Although it is less sensitive than EIA, its greater accessibility, and the fact that treatment can be given on the same day, means that the use of POCT would result in a higher proportion of women with syphilis receiving treatment than with the EIA in this district of Tanzania.
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Affiliation(s)
- Pieter W. Smit
- Department of Infectious & Tropical diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - David Mabey
- Department of Infectious & Tropical diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | | | - Julius Mngara
- National Institute for Medical Research, Mwanza, Tanzania
| | - Benjamin Clark
- National Institute for Medical Research, Mwanza, Tanzania
| | - Aura Andreasen
- Department of Infectious & Tropical diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Mwanza intervention Trials Unit, Mwanza, Tanzania
| | - Jim Todd
- Department of Infectious & Tropical diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
- National Institute for Medical Research, Mwanza, Tanzania
| | - Mark Urassa
- National Institute for Medical Research, Mwanza, Tanzania
| | - Basia Zaba
- Department of Infectious & Tropical diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Rosanna W. Peeling
- Department of Infectious & Tropical diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
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State-of-the-art dried blood spot analysis: an overview of recent advances and future trends. Bioanalysis 2013; 5:2187-208. [DOI: 10.4155/bio.13.175] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Dried blood spots have become a popular method in a variety of micro blood-sampling techniques in the life sciences sector, consequently competing with the field of conventional, invasive blood sampling by venepuncture. Dried blood spots are widely applied in numerous bioanalytical assays and have gained a significant role in the screening of inherited metabolic diseases, in PK and PD modeling; in the treatment and diagnosis of infectious diseases; and in therapeutic drug monitoring. Recent technological developments such as automation, online extraction, mass spectrometric direct analysis and also conventional dried blood spot bioanalysis, as well as future developments in dried blood spot bioanalysis are highlighted and presented in this article.
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