1
|
Hunter PJ, Awoyemi T, Ayede AI, Chico RM, David AL, Dewey KG, Duggan CP, Gravett M, Prendergast AJ, Ramakrishnan U, Ashorn P, Klein N. Biological and pathological mechanisms leading to the birth of a small vulnerable newborn. Lancet 2023; 401:1720-1732. [PMID: 37167990 DOI: 10.1016/s0140-6736(23)00573-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 03/08/2023] [Accepted: 03/14/2023] [Indexed: 05/13/2023]
Abstract
The pathway to a thriving newborn begins before conception and continues in utero with a healthy placenta and the right balance of nutrients and growth factors that are timed and sequenced alongside hormonal suppression of labour until a mature infant is ready for birth. Optimal nutrition that includes adequate quantities of quality protein, energy, essential fats, and an extensive range of vitamins and minerals not only supports fetal growth but could also prevent preterm birth by supporting the immune system and alleviating oxidative stress. Infection, illness, undernourishment, and harmful environmental exposures can alter this trajectory leading to an infant who is too small due to either poor growth during pregnancy or preterm birth. Systemic inflammation suppresses fetal growth by interfering with growth hormone and its regulation of insulin-like growth factors. Evidence supports the prevention and treatment of several maternal infections during pregnancy to improve newborn health. However, microbes, such as Ureaplasma species, which are able to ascend the cervix and cause membrane rupture and chorioamnionitis, require new strategies for detection and treatment. The surge in fetal cortisol late in pregnancy is essential to parturition at the right time, but acute or chronically high maternal cortisol levels caused by psychological or physical stress could also trigger labour onset prematurely. In every pathway to the small vulnerable newborn, there is a possibility to modify the course of pregnancy by supporting improved nutrition, protection against infection, holistic maternal wellness, and healthy environments.
Collapse
Affiliation(s)
- Patricia J Hunter
- UCL Great Ormond Street Institute of Child Health, University College London, London, UK.
| | | | - Adejumoke I Ayede
- Department of Paediatrics, College of Medicine, University of Ibadan and University College Hospital, Ibadan, Nigeria
| | - R Matthew Chico
- Department of Disease Control, Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Anna L David
- UCL Elizabeth Garrett Anderson Institute for Women's Health, University College London, London, UK
| | - Kathryn G Dewey
- Department of Nutrition, University of California at Davis, Davis, CA, USA
| | - Christopher P Duggan
- Department of Nutrition and Department of Global Health and Population, Harvard TH Chan School of Public Health, Boston, MA, USA; Center for Nutrition, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Michael Gravett
- Department of Obstetrics & Gynecology, University of Washington, Seattle, WA, USA
| | - Andrew J Prendergast
- Blizard Institute, Queen Mary University of London, London, UK; Zvitambo Institute for Maternal & Child Health Research, Harare, Zimbabwe
| | | | - Per Ashorn
- Center for Child, Adolescent, and Maternal Health Research, Faculty of Medicine and Health Technology, Tampere University and Tampere University Hospital, Tampere, Finland
| | - Nigel Klein
- UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| |
Collapse
|
2
|
Bhargava A, Nagia S, Verma P, Bansal S, Khnuger N, Saxena A. Does performance and operational superiority of point-of-care test make it the investigation of choice in confirming syphilis? Indian J Sex Transm Dis AIDS 2022; 43:146-149. [PMID: 36743121 PMCID: PMC9891019 DOI: 10.4103/ijstd.ijstd_30_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 03/21/2022] [Accepted: 04/08/2022] [Indexed: 11/17/2022] Open
Abstract
Background According to the World Health Organization, 6 million cases of syphilis occur every year. Serological tests for syphilis form the mainstay of diagnosis for syphilis. We evaluated the performance of point-of-care test (POCT) against other specific treponemal test for confirming the diagnosis of syphilis. Materials and Methods Does performance and operational superiority of POCT make it the investigation of choice in confirming syphilis? Retrospectively, data were analyzed of 599 serum samples from Apex Regional sexually transmitted disease centre, Safdarjung Hospital, New Delhi, received for testing by syphilis treponemal assays (both nontreponemal reactive and nonreactive). These samples underwent treponemal testing for syphilis by the Treponema pallidum hemagglutination (TPHA), fluorescent treponemal antibody absorption test (FTA-ABS), and POCT. Performance characteristics (sensitivity, specificity, positive predictive value [PPV], negative predictive value [NPV], and diagnostic accuracy), and operational characteristics of POCT and TPHA were evaluated against the gold standard FTA-ABS. Results A total of 599 samples were evaluated, of which 61.76% were positive by FTA-ABS. On analysis, the sensitivity was 91.08% and 91.89%, specificity was 89.08% and 87.34%, PPV was 93.09% and 92.14%, NPV was 86.08% and 86.96%, and diagnostic accuracy was 90.32% and 90.15% for POCT and TPHA, respectively. The lower cost, shorter turnaround time, lesser infrastructure and workforce need, and easy availability make the POCT operationally superior to TPHA. Conclusion Owing to its operational superiority and higher specificity POCT can replace TPHA for confirming the diagnosis of Syphilis. POCT are affordable, equipment free, have room temperature storage, and yield result within 15 minutes, enabling same day testing and treatment. It can be used in a resource limited setting, for community setup or even self-testing.
Collapse
Affiliation(s)
- Aradhana Bhargava
- Apex Regional STD Centre, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi, India
| | - Sonal Nagia
- Department of Dermatology and STD, Apex Regional STD Centre, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi, India
| | - Prashant Verma
- Department of Dermatology and STD, Apex Regional STD Centre, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi, India
| | - Shikha Bansal
- Department of Dermatology and STD, Apex Regional STD Centre, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi, India
| | - Niti Khnuger
- Department of Dermatology and STD, Apex Regional STD Centre, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi, India
| | - Ashok Saxena
- Department of Dermatology and STD, Apex Regional STD Centre, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi, India
| |
Collapse
|
3
|
Zhou Y, Wu Y, Ding L, Huang X, Xiong Y. Point-of-care COVID-19 diagnostics powered by lateral flow assay. Trends Analyt Chem 2021; 145:116452. [PMID: 34629572 PMCID: PMC8487324 DOI: 10.1016/j.trac.2021.116452] [Citation(s) in RCA: 86] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Since its first discovery in December 2019, the global coronavirus disease 2019 (COVID-19) pandemic caused by the novel coronavirus (SARS-CoV-2) has been posing a serious threat to human life and health. Diagnostic testing is critical for the control and management of the COVID-19 pandemic. In particular, diagnostic testing at the point of care (POC) has been widely accepted as part of the post restriction COVID-19 control strategy. Lateral flow assay (LFA) is a popular POC diagnostic platform that plays an important role in controlling the COVID-19 pandemic in industrialized countries and resource-limited settings. Numerous pioneering studies on the design and development of diverse LFA-based diagnostic technologies for the rapid diagnosis of COVID-19 have been done and reported by researchers. Hundreds of LFA-based diagnostic prototypes have sprung up, some of which have been developed into commercial test kits for the rapid diagnosis of COVID-19. In this review, we summarize the crucial role of rapid diagnostic tests using LFA in targeting SARS-CoV-2-specific RNA, antibodies, antigens, and whole virus. Then, we discuss the design principle and working mechanisms of these available LFA methods, emphasizing their clinical diagnostic efficiency. Ultimately, we elaborate the challenges of current LFA diagnostics for COVID-19 and highlight the need for continuous improvement in rapid diagnostic tests.
Collapse
Affiliation(s)
- Yaofeng Zhou
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, PR China
- School of Food Science and Technology, Nanchang University, Nanchang, 330047, PR China
| | - Yuhao Wu
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, PR China
- School of Food Science and Technology, Nanchang University, Nanchang, 330047, PR China
| | - Lu Ding
- Hypertension Research Institute of Jiangxi Province, Department of Cardiology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, 330006, PR China
| | - Xiaolin Huang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, PR China
- School of Food Science and Technology, Nanchang University, Nanchang, 330047, PR China
| | - Yonghua Xiong
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, PR China
- School of Food Science and Technology, Nanchang University, Nanchang, 330047, PR China
| |
Collapse
|
4
|
Han JY, DeVoe DL. Plasma Isolation in a Syringe by Conformal Integration of Inertial Microfluidics. Ann Biomed Eng 2020; 49:139-148. [PMID: 32367467 DOI: 10.1007/s10439-020-02526-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 04/28/2020] [Indexed: 11/29/2022]
Abstract
A thermoplastic microfluidic substrate is conformally integrated onto the cylindrical barrel of a conventional venipuncture syringe, forming a spiral inertial separation element supporting the isolation of plasma from diluted whole blood. The cylindrical shape of the syringe itself serves to define the flow path required for inertial separation by transforming a linear microchannel to a spiral topology. The hybrid system enables inertial plasma separation by Dean flow focusing within the same syringe used for a patient blood draw, with the seamlessly interconnected microfluidic element operated by automated or manual actuation of the syringe plunger. Plasma isolation is achieved without the need for external instrumentation. Device design and fabrication challenges are discussed, and effective plasma isolation within the system is demonstrated, with a peak separation efficiency above 97% using 25 × diluted blood.
Collapse
Affiliation(s)
- Jung Y Han
- Department of Mechanical Engineering, University of Maryland, College Park, MD, 20742, USA
| | - Don L DeVoe
- Department of Mechanical Engineering, University of Maryland, College Park, MD, 20742, USA.
| |
Collapse
|
5
|
Miesler T, Wimschneider C, Brem A, Meinel L. Frugal Innovation for Point-of-Care Diagnostics Controlling Outbreaks and Epidemics. ACS Biomater Sci Eng 2020; 6:2709-2725. [PMID: 33463254 DOI: 10.1021/acsbiomaterials.9b01712] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Today epidemics of infectious diseases occur more often and spread both faster and further due to globalization and changes in our lifestyle. One way to meet these biological threats are so-called "Frugal Innovations", which focus on the development of affordable, rapid, and easy-to-use diagnostics with widespread use. In this context, point-of-care-tests (POCTs), performed at the patient's bedside, reduce extensive waiting times and unnecessary treatments and enable effective containment measures. This Perspective covers advances in POCT diagnostics on the basis of frugal innovation characteristics that will enable a faster, less expensive, and more convenient reaction to upcoming epidemics. Established POCT systems on the health care market, as well as currently evolving technological advancements in that sector are discussed. Progress in POCT technology and insights on how to most effectively use them allows the handling of more patients in a shorter time frame and consequently improves clinical outcomes at lower cost.
Collapse
Affiliation(s)
- Tobias Miesler
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg Germany
| | - Christine Wimschneider
- Chair of Technology Management, FAU Erlangen-Nürnberg, Dr.-Mack-Str. 81, 90762 Fürth, Germany
| | - Alexander Brem
- Institute of Entrepreneurship & Innovation, University of Stuttgart, Pfaffenwaldring 19, 70569 Stuttgart, Germany.,Mads Clausen Institute, University of Southern Denmark, Alsion 1, 6400 Sonderborg, Denmark
| | - Lorenz Meinel
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg Germany.,Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Center for Infection Research (HZI), Würzburg, Germany
| |
Collapse
|
6
|
Kabir MA, Zilouchian H, Sher M, Asghar W. Development of a Flow-Free Automated Colorimetric Detection Assay Integrated with Smartphone for Zika NS1. Diagnostics (Basel) 2020; 10:diagnostics10010042. [PMID: 31947549 PMCID: PMC7168132 DOI: 10.3390/diagnostics10010042] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 01/06/2020] [Accepted: 01/12/2020] [Indexed: 12/11/2022] Open
Abstract
The Zika virus (ZIKV) is an emerging flavivirus transmitted to humans by Aedes mosquitoes that can potentially cause microcephaly, Guillain–Barré Syndrome, and other birth defects. Effective vaccines for Zika have not yet been developed. There is a necessity to establish an easily deployable, high-throughput, low-cost, and disposable point-of-care (POC) diagnostic platform for ZIKV infections. We report here an automated magnetic actuation platform suitable for a POC microfluidic sandwich enzyme-linked immunosorbent assay (ELISA) using antibody-coated superparamagnetic beads. The smartphone integrated immunoassay is developed for colorimetric detection of ZIKV nonstructural protein 1 (NS1) antigen using disposable chips to accommodate the reactions inside the chip in microliter volumes. An in-house-built magnetic actuator platform automatically moves the magnetic beads through different aqueous phases. The assay requires a total of 9 min to automatically control the post-capture washing, horseradish peroxidase (HRP) conjugated secondary antibody probing, washing again, and, finally, color development. By measuring the saturation intensity of the developed color from the smartphone captured video, the presented assay provides high sensitivity with a detection limit of 62.5 ng/mL in whole plasma. These results advocate a great promise that the platform would be useful for the POC diagnosis of Zika virus infection in patients and can be used in resource-limited settings.
Collapse
Affiliation(s)
- Md Alamgir Kabir
- Department of Computer & Electrical Engineering and Computer Science, Florida Atlantic University, Boca Raton, FL 33431, USA; (M.A.K.); (M.S.)
- Asghar-Lab, Micro and Nanotechnology in Medicine, College of Engineering and Computer Science, Boca Raton, FL 33431, USA;
| | - Hussein Zilouchian
- Asghar-Lab, Micro and Nanotechnology in Medicine, College of Engineering and Computer Science, Boca Raton, FL 33431, USA;
| | - Mazhar Sher
- Department of Computer & Electrical Engineering and Computer Science, Florida Atlantic University, Boca Raton, FL 33431, USA; (M.A.K.); (M.S.)
- Asghar-Lab, Micro and Nanotechnology in Medicine, College of Engineering and Computer Science, Boca Raton, FL 33431, USA;
| | - Waseem Asghar
- Department of Computer & Electrical Engineering and Computer Science, Florida Atlantic University, Boca Raton, FL 33431, USA; (M.A.K.); (M.S.)
- Asghar-Lab, Micro and Nanotechnology in Medicine, College of Engineering and Computer Science, Boca Raton, FL 33431, USA;
- Department of Biological Sciences (Courtesy Appointment), Florida Atlantic University, Boca Raton, FL 33431, USA
- Correspondence:
| |
Collapse
|
7
|
Parolo C, Greenwood AS, Ogden NE, Kang D, Hawes C, Ortega G, Arroyo-Currás N, Plaxco KW. E-DNA scaffold sensors and the reagentless, single-step, measurement of HIV-diagnostic antibodies in human serum. MICROSYSTEMS & NANOENGINEERING 2020; 6:13. [PMID: 34567628 PMCID: PMC8433188 DOI: 10.1038/s41378-019-0119-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 10/28/2019] [Accepted: 11/07/2019] [Indexed: 05/05/2023]
Abstract
The multiplexed, point-of-care measurement of specific antibodies could improve the speed with which diseases are diagnosed and their treatment initiated. To this end, we are developing E-DNA scaffold sensors, which consist of a rigid, nucleic acid "scaffold" attached on one end to an electrode and presenting both a redox reporter and an epitope on the other. In the absence of antibody, the reporter efficiently transfers electrons when interrogated electrochemically. Binding-induced steric hindrance limits movement, reducing electron transfer in a manner that is both easily measured and quantitatively related to target concentration. Previously we have used monoclonal antibodies to explore the analytical performance of E-DNA sensors, showing that they support the rapid, single-step, quantitative detection of multiple antibodies in small volume samples. Here, in contrast, we employ authentic human samples to better explore the platform's clinical potential. Specifically, we developed E-DNA sensors targeting three HIV-specific antibodies and then compared the analytical and clinical performance of these against those of gold standard serological techniques. Doing so we find that, although the multistep amplification of an ELISA leads to a lower detection limits, the clinical sensitivity of ELISAs, E-DNA sensors and lateral-flow dipsticks are indistinguishable across our test set. It thus appears that, by merging the quantitation and multiplexing of ELISAs with the convenience and speed of dipsticks, E-DNA scaffold sensors could significantly improve on current serological practice.
Collapse
Affiliation(s)
- Claudio Parolo
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, CA USA
| | - Ava S. Greenwood
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, CA USA
| | - Nathan E. Ogden
- Department of Materials, University of California, Santa Barbara, Santa Barbara, CA USA
| | - Di Kang
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, CA USA
| | - Chase Hawes
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, CA USA
| | - Gabriel Ortega
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, CA USA
| | | | - Kevin W. Plaxco
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, CA USA
- Interdepartmental Program in Biomolecular Science and Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106 USA
| |
Collapse
|
8
|
Guy RJ, Ward J, Causer LM, Natoli L, Badman SG, Tangey A, Hengel B, Wand H, Whiley D, Tabrizi SN, Shephard M, Fairley CK, Donovan B, Anderson DA, Regan DG, Maher L, Kaldor JM. Molecular point-of-care testing for chlamydia and gonorrhoea in Indigenous Australians attending remote primary health services (TTANGO): a cluster-randomised, controlled, crossover trial. THE LANCET. INFECTIOUS DISEASES 2019; 18:1117-1126. [PMID: 30303108 DOI: 10.1016/s1473-3099(18)30429-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 06/13/2018] [Accepted: 07/03/2018] [Indexed: 02/06/2023]
Abstract
BACKGROUND Timely diagnosis and treatment of sexually transmissible infections will prevent morbidity and onward transmission. We aimed to assess the efficacy of a point-of-care molecular test for Chlamydia trachomatis and Neisseria gonorrhoeae infections at the cluster level to improve infection management among Indigenous Australian communities with high prevalence of sexually transmissible infections. METHODS In this cluster-randomised crossover study, we recruited primary health services in Western Australia, Far North Queensland, and South Australia that provide care to Indigenous people in regional or remote locations. The services were eligible if they did 150 or more tests for C trachomatis or N gonorrhoeae infection per year among individuals aged 16-29 years, and if C trachomatis or N gonorrhoeae positivity was 10% or higher. Services were randomly assigned (1:1) by use of a random-number generator, stratified by geographical region, to either standard care conditions with routine laboratory-based sexually transmissible infection testing for 12 months followed by 12 months of intervention with molecular point-of-care testing, or the reverse sequence. The primary outcome was the proportion of people (aged 16-29 years) found to have C trachomatis or N gonorrhoeae who had a positive result at retesting 3 weeks to 3 months after treatment, and a secondary outcome was treatment within 7 days, both in those aged 16-29 years and at the cluster level. We did these analyses using data from all participants who had a positive result at testing, by point-of-care of laboratory testing (ie, the intention-to-treat population). The trial is registered with Australian and New Zealand Clinical Trials Registry (ACTRN12613000808741). FINDINGS Between June 1, 2013, and Feb 29, 2016, 12 health services were enrolled and randomly assigned to standard care followed by intervention (six) and the reverse sequence (six). After randomisation, one health service that was initially assigned to standard care was excluded because it no longer met the inclusion criteria. 455 individuals tested positive for C trachomatis or N gonorrhoeae infection in the intervention group, and 405 tested positive in the standard care group. In the intervention group, 12 (19%) of 63 individuals retested had a positive test result, compared with nine (13%) of 67 with positive retests in the standard care group (relative ratio [RR] 1·42, 95% CI 0·64-3·13; p=0·405), and 347 (76%) were treated within 7 days in the intervention group, compared with 191 (47%) in the standard care group (RR 1·66, 1·41-1·93; p<0·0001). INTERPRETATION Retesting rates were too low to draw conclusions on the effect of the intervention on repeat infections. Further research will be needed to determine whether point-of-care tests have an effect on reinfection rates, and the sustainability of using this technology. However, our findings show that time to treatment of C trachomatis or N gonorrhoeae infections in primary care clinics in remote areas in Australia with a high prevalence of sexually transmissible infections could be substantially reduced by the use of molecular point-of-care tests. FUNDING The National Health and Medical Research Council, Australia.
Collapse
Affiliation(s)
| | - James Ward
- South Australian Health and Medical Research Institute, Adelaide, SA, Australia
| | | | | | | | - Annie Tangey
- The Kirby Institute, UNSW Sydney, NSW, Australia; Ngaanyatjarra Health Service, Alice Springs, NT, Australia
| | - Belinda Hengel
- Apunipima Cape York Health Council, Westcourt, QLD, Australia
| | - Handan Wand
- The Kirby Institute, UNSW Sydney, NSW, Australia
| | - David Whiley
- Centre for Clinical Research, The University of Queensland, Herston, QLD, Australia
| | - Sepehr N Tabrizi
- Department of Microbiology, The Royal Women's Hospital and Murdoch Children's Research Institute, Parkville, VIC, Australia; Department of Obstetrics and Gynaecology, University of Melbourne, VIC, Australia
| | - Mark Shephard
- International Centre for Point-of-Care Testing, Flinders University, Sturt Campus, Bedford Park, SA, Australia
| | - Christopher K Fairley
- Central Clinical School, Monash University, Melbourne, VIC, Australia; Melbourne Sexual Health Centre, Carlton, VIC, Australia
| | - Basil Donovan
- The Kirby Institute, UNSW Sydney, NSW, Australia; Sydney Sexual Health Centre, Sydney Hospital, Sydney, NSW, Australia
| | | | | | - Lisa Maher
- The Kirby Institute, UNSW Sydney, NSW, Australia
| | | |
Collapse
|
9
|
Halvorsen CP, Olson L, Araújo AC, Karlsson M, Nguyễn TT, Khu DTK, Le HTT, Nguyễn HTB, Winbladh B, Russom A. A rapid smartphone-based lactate dehydrogenase test for neonatal diagnostics at the point of care. Sci Rep 2019; 9:9301. [PMID: 31243323 PMCID: PMC6595069 DOI: 10.1038/s41598-019-45606-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 06/07/2019] [Indexed: 11/09/2022] Open
Abstract
There is a growing recognition of the importance of point-of-care tests (POCTs) for detecting critical neonatal illnesses to reduce the mortality rate in newborns, especially in low-income countries, which account for 98 percent of reported neonatal deaths. Lactate dehydrogenase (LDH) is a marker of cellular damage as a result of hypoxia-ischemia in affected organs. Here, we describe and test a POC LDH test direct from whole blood to provide early indication of serious illness in the neonate. The sample-in-result-out POC platform is specifically designed to meet the needs at resource-limited settings. Plasma is separated from whole blood on filter paper with dried-down reagents for colorimetric reaction, combined with software for analysis using a smartphone. The method was clinically tested in newborns in two different settings. In a clinical cohort of newborns of Stockholm (n = 62) and Hanoi (n = 26), the value of R using Pearson's correlation test was 0.91 (p < 0.01) and the R2 = 0.83 between the two methods. The mean LDH (±SD) for the reference method vs. the POC-LDH was 551 (±280) U/L and 552 (±249) U/L respectively, indicating the clinical value of LDH values measured in minutes with the POC was comparable with standardized laboratory analyses.
Collapse
Affiliation(s)
- Cecilia Pegelow Halvorsen
- Department of clinical research and education, Södersjukhuset, Karolinska Institutet, Stockholm, Sweden.,Neonatal Unit at Sachs' Children and Youth hospital, Stockholm, Sweden
| | - Linus Olson
- Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden.,Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden.,Training and Research Academic Collaboration (TRAC) Sweden - Vietnam, Hanoi, Vietnam
| | | | - Mathias Karlsson
- Calmark Sweden AB, Stockholm, Sweden.,Department of Medical Sciences, Biomedical Structure and Function, Uppsala University, Uppsala, Sweden
| | - Trang Thị Nguyễn
- Neonatal Intensive Care Unit, Vietnam National Children's Hospital, Hanoi, Vietnam.,Research Institute for Child Health, Hanoi, Vietnam
| | - Dung T K Khu
- Training and Research Academic Collaboration (TRAC) Sweden - Vietnam, Hanoi, Vietnam.,Neonatal Intensive Care Unit, Vietnam National Children's Hospital, Hanoi, Vietnam
| | - Ha T T Le
- Neonatal Intensive Care Unit, Vietnam National Children's Hospital, Hanoi, Vietnam.,Research Institute for Child Health, Hanoi, Vietnam
| | - Hoa T B Nguyễn
- Neonatal Intensive Care Unit, Vietnam National Children's Hospital, Hanoi, Vietnam.,Research Institute for Child Health, Hanoi, Vietnam
| | - Birger Winbladh
- Department of clinical research and education, Södersjukhuset, Karolinska Institutet, Stockholm, Sweden
| | - Aman Russom
- Division of Nanobiotechnology, Department of Protein Science, Science for Life Laboratory, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Stockholm, Sweden.
| |
Collapse
|
10
|
Point-of-care tests to reduce the burden of sexually transmitted infections. THE LANCET. INFECTIOUS DISEASES 2019; 19:570-571. [PMID: 31036512 DOI: 10.1016/s1473-3099(18)30783-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 12/10/2018] [Indexed: 11/20/2022]
|
11
|
Warkad SD, Nimse SB, Song KS, Kim T. HCV Detection, Discrimination, and Genotyping Technologies. SENSORS (BASEL, SWITZERLAND) 2018; 18:E3423. [PMID: 30322029 PMCID: PMC6210034 DOI: 10.3390/s18103423] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 10/05/2018] [Accepted: 10/10/2018] [Indexed: 02/06/2023]
Abstract
According to the World Health Organization (WHO), 71 million people were living with Hepatitis C virus (HCV) infection worldwide in 2015. Each year, about 399,000 HCV-infected people succumb to cirrhosis, hepatocellular carcinoma, and liver failure. Therefore, screening of HCV infection with simple, rapid, but highly sensitive and specific methods can help to curb the global burden on HCV healthcare. Apart from the determination of viral load/viral clearance, the identification of specific HCV genotype is also critical for successful treatment of hepatitis C. This critical review focuses on the technologies used for the detection, discrimination, and genotyping of HCV in clinical samples. This article also focuses on advantages and disadvantages of the reported methods used for HCV detection, quantification, and genotyping.
Collapse
Affiliation(s)
- Shrikant Dashrath Warkad
- Institute for Applied Chemistry and Department of Chemistry, Hallym University, Chuncheon 200-702, Korea.
| | - Satish Balasaheb Nimse
- Institute for Applied Chemistry and Department of Chemistry, Hallym University, Chuncheon 200-702, Korea.
| | - Keum-Soo Song
- Institute for Applied Chemistry and Department of Chemistry, Hallym University, Chuncheon 200-702, Korea.
| | - Taisun Kim
- Institute for Applied Chemistry and Department of Chemistry, Hallym University, Chuncheon 200-702, Korea.
| |
Collapse
|
12
|
Mashamba-Thompson TP, Moodley P, Sartorius B, Drain PK. Evaluation of antenatal rapid human immunodeficiency virus testing in rural South Africa. South Afr J HIV Med 2018. [DOI: 10.4102/sajhivmed.v19i1.771] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Introduction: South African guidelines recommend two rapid tests for diagnosing human immunodeficiency virus (HIV) using the serial HIV testing algorithm, but the accuracy and compliance to this algorithm is unknown in rural clinics. We evaluated the accuracy of HIV rapid testing and the time to receiving test results among pregnant women in rural KwaZulu-Natal (KZN).Method: We observed the accuracy of rapid HIV testing algorithms for 208 consenting antenatal patients accessing voluntary HIV testing services in nine rural primary healthcare (PHC) clinics in KZN. A PHC-based HIV counsellor obtained finger-prick whole blood from each participant to perform rapid testing using the Advanced Quality™ One Step anti-HIV (1&2) and/or ABON™ HIV 1/2/O Tri-Line HIV test. A research nurse obtained venous blood for an enzyme-linked immunosorbent assay (ELISA) HIV test, which is the gold standard diagnostic test. We recorded the time of receipt of HIV test results for each test.Results: Among 208 pregnant women with a mean age of 26 years, 72 women from nine rural PHC clinics were identified as HIV-positive by two rapid tests with an HIV-prevalence of 35% (95% Bayesian credibility intervals [BCI]: 28% – 41%). Of the 208 patients, 135 patients from six clinics were tested with the serial HIV testing algorithm. The estimated sensitivity and specificity for the 135 participants were 100% (95% confidence interval [CI]: 93% – 100%) and 99% (CI: 95% – 100%), respectively. The positive predictive value and negative predictive value were estimated at 98% (CI: 94% – 100%) and 95% (CI: 88% – 99%), respectively. All women received their HIV rapid test results within 20 min of testing. Test stock-out resulted in poor test availability at point-of-care, preventing performance of a second HIV test in three out of nine PHC clinics in rural KZN.Conclusion: Despite the poor compliance with national guidelines for HIV rapid testing services, HIV rapid test results provided to pregnant women in rural PHC clinics in KZN were generally accurate and timely. Test stock-out was shown to be one of the barriers to test availability in rural PHC clinics, resulting in poor compliance with guidelines. We recommend a compulsory confirmation HIV rapid test for all HIV-negative test results obtained from pregnant patients in rural and resource-limited settings.
Collapse
|
13
|
Toskin I, Peeling RW, Mabey D, Holmes K, Ballard R, Kiarie J, Askew I. Point-of-care tests for STIs: the way forward. Sex Transm Infect 2018; 93:S1-S2. [PMID: 29223958 DOI: 10.1136/sextrans-2016-053074] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 06/21/2017] [Accepted: 07/02/2017] [Indexed: 11/03/2022] Open
Affiliation(s)
- Igor Toskin
- Department of Reproductive Health and Research, World Health Organization, Geneva, Switzerland
| | - Rosanna W Peeling
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, UK
| | - David Mabey
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - King Holmes
- Department of Global Health & Medicine, University of Washington, Seattle, Washington, USA
| | - Ronald Ballard
- Department of Reproductive Health and Research, World Health Organization, Geneva, Switzerland
| | - James Kiarie
- Department of Reproductive Health and Research, World Health Organization, Geneva, Switzerland
| | - Ian Askew
- Department of Reproductive Health and Research, World Health Organization, Geneva, Switzerland
| |
Collapse
|
14
|
Surveillance of intestinal schistosomiasis during control: a comparison of four diagnostic tests across five Ugandan primary schools in the Lake Albert region. Parasitology 2018; 145:1715-1722. [PMID: 29560841 PMCID: PMC6533640 DOI: 10.1017/s003118201800029x] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Programmatic surveillance of intestinal schistosomiasis during control can typically use four diagnostic tests, either singularly or in combination, but these have yet to be cross-compared directly. Our study assembled a complete diagnostic dataset, inclusive of infection intensities, from 258 children from five Ugandan primary schools. The schools were purposely selected as typical of the endemic landscape near Lake Albert and reflective of high- and low-transmission settings. Overall prevalence was: 44.1% (95% CI 38.0–50.2) by microscopy of duplicate Kato-Katz smears from two consecutive stools, 56.9% (95% CI 50.8–63.0) by urine-circulating cathodic antigen (CCA) dipstick, 67.4% (95% CI 61.6–73.1) by DNA-TaqMan® and 75.1% (95% CI 69.8–80.4) by soluble egg antigen enzyme-linked immunosorbent assay (SEA-ELISA). A cross-comparison of diagnostic sensitivities, specificities, positive and negative predictive values was undertaken, inclusive of a latent class analysis (LCA) with a LCA-model estimate of prevalence by each school. The latter ranged from 9.6% to 100.0%, and prevalence by school for each diagnostic test followed a static ascending order or monotonic series of Kato-Katz, urine-CCA dipstick, DNA-TaqMan® and SEA-ELISA. We confirm that Kato-Katz remains a satisfactory diagnostic standalone in high-transmission settings but in low-transmission settings should be augmented or replaced by urine-CCA dipsticks. DNA-TaqMan® appears suitable in both endemic settings though is only implementable if resources permit. In low-transmission settings, SEA-ELISA remains the method of choice to evidence an absence infection. We discuss the pros and cons of each method concluding that future surveillance of intestinal schistosomiasis would benefit from a flexible, context-specific approach both in choice and application of each diagnostic method, rather than a single one-size fits all approach.
Collapse
|
15
|
Guy RJ, Causer LM, Klausner JD, Unemo M, Toskin I, Azzini AM, Peeling RW. Performance and operational characteristics of point-of-care tests for the diagnosis of urogenital gonococcal infections. Sex Transm Infect 2018; 93:S16-S21. [PMID: 29223959 DOI: 10.1136/sextrans-2017-053192] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 07/30/2017] [Accepted: 08/08/2017] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND In 2012, there was an estimated 78 million new cases of gonorrhoea globally. Untreated infection may lead to reproductive and neonatal morbidity and facilitate HIV transmission. Diagnosis and treatment are a priority for control and prevention, yet use of point-of-care tests (POCTs) for Neisseria gonorrhoeae (NG) is limited. OBJECTIVES To review the performance and operational characteristics of NG POCTs for diagnosis of urogenital gonorrhoea. METHODS We compiled and synthesised findings from two separate systematic reviews which included evaluations published until August 2015. RESULTS Six tests were included: five were immunochromatographic tests (ICTs) or optical immunoassay (OIAs) based on antigen detection; with 5-7 steps and results in 25-40 min, and one (GeneXpert CT/NG) was a 'near-patient test' based on nucleic acid amplification technique (NAAT); with three steps, electricity required, and results in 90 min. When compared with laboratory-based NAATs as the reference tests, sensitivities of ICT and OIA-based POCTs ranged from 12.5% to 70% when cervical/vaginal swabs were tested. Specificities ranged from 89% to 99.8%. The near-patient NAAT had sensitivities of >95% and specificities of >99.8% consistently across all specimen types (urine, cervical and vaginal swabs). CONCLUSIONS Based on a limited number of evaluations, antigen detection POCTs for NG lacked sufficient sensitivity to be used for screening. A near-patient NAAT has acceptable performance, only involved a few steps, but needs electricity, a temperature-controlled environment and has a 90 min run time. To achieve wider scale up of NG POCTs, we need strong evidence of cost-effectiveness, which should inform guidelines and ultimately increase test development, demand and reduce costs.
Collapse
Affiliation(s)
- Rebecca J Guy
- The Kirby Institute, University of New South Wales, Sydney, Australia
| | - Louise M Causer
- The Kirby Institute, University of New South Wales, Sydney, Australia
| | - Jeffrey D Klausner
- Department of Global Health, University of California at Los Angeles, San Francisco, USA
| | - Magnus Unemo
- WHO Collaborating Centre for Gonorrhoea and other STIs, Örebro University Hospital, Örebro, Sweden
| | - Igor Toskin
- Department of Reproductive Health and Research, World Health Organization, Geneva, Switzerland
| | | | - Rosanna W Peeling
- Department of Clinical Research, London School of Hygiene & Tropical Medicine, London, UK
| |
Collapse
|
16
|
Phang Romero Casas C, Martyn-St James M, Hamilton J, Marinho DS, Castro R, Harnan S. Rapid diagnostic test for antenatal syphilis screening in low-income and middle-income countries: a systematic review and meta-analysis. BMJ Open 2018; 8:e018132. [PMID: 29467132 PMCID: PMC5855314 DOI: 10.1136/bmjopen-2017-018132] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES To undertake a systematic review and meta-analysis to evaluate the test performance including sensitivity and specificity of rapid immunochromatographic syphilis (ICS) point-of-care (POC) tests at antenatal clinics compared with reference standard tests (non-treponemal (TP) and TP tests) for active syphilis in pregnant women. METHODS Five electronic databases were searched (PubMed, EMBASE, CRD, Cochrane Library and LILACS) to March 2016 for diagnostic accuracy studies of ICS test and standard reference tests for syphilis in pregnant women. Methodological quality was assessed using QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies). A bivariate meta-analysis was undertaken to generate pooled estimates of diagnostic parameters. Results were presented using a coupled forest plot of sensitivity and specificity and a scatter plot. RESULTS The methodological quality of the five included studies with regards to risk of bias and applicability concern judgements was either low or unclear. One study was judged as high risk of bias for patient selection due to exclusion of pregnant women with a previous history of syphilis, and one study was judged at high risk of bias for study flow and timing as not all patients were included in the analysis. Five studies contributed to the meta-analysis, providing a pooled sensitivity and specificity for ICS of 0.85 (95% CrI: 0.73 to 0.92) and 0.98 (95% CrI: 0.95 to 0.99), respectively. CONCLUSIONS This review and meta-analysis observed that rapid ICS POC tests have a high sensitivity and specificity when performed in pregnant women at antenatal clinics. However, the methodological quality of the existing evidence base should be taken into consideration when interpreting these results. PROSPERO REGISTRATION NUMBER CRD42016036335.
Collapse
Affiliation(s)
- Carmen Phang Romero Casas
- Centro de Desenvolvimento Tecnológico em Saúde (CDTS), Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Rio de Janeiro, Brazil
- National Institute for Science and Technology on Innovation on Diseases of Neglected Populations (INCT/IDPN), National Council for Scientific and Technological Development (CNPq), Brazil
| | | | - Jean Hamilton
- School of Health and Related Research, University of Sheffield, Sheffield, UK
| | - Daniel S Marinho
- Centro de Desenvolvimento Tecnológico em Saúde (CDTS), Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Rio de Janeiro, Brazil
- National Institute for Science and Technology on Innovation on Diseases of Neglected Populations (INCT/IDPN), National Council for Scientific and Technological Development (CNPq), Brazil
| | - Rodolfo Castro
- National Institute for Science and Technology on Innovation on Diseases of Neglected Populations (INCT/IDPN), National Council for Scientific and Technological Development (CNPq), Brazil
- Instituto Nacional de Infectologia Evandro Chagas (INI), Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
- Instituto de Saúde Coletiva, Universidade Federal do Estado do Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil
| | - Sue Harnan
- School of Health and Related Research, University of Sheffield, Sheffield, UK
| |
Collapse
|
17
|
Unemo M, Bradshaw CS, Hocking JS, de Vries HJC, Francis SC, Mabey D, Marrazzo JM, Sonder GJB, Schwebke JR, Hoornenborg E, Peeling RW, Philip SS, Low N, Fairley CK. Sexually transmitted infections: challenges ahead. THE LANCET. INFECTIOUS DISEASES 2017; 17:e235-e279. [PMID: 28701272 DOI: 10.1016/s1473-3099(17)30310-9] [Citation(s) in RCA: 441] [Impact Index Per Article: 63.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 03/13/2017] [Accepted: 03/30/2017] [Indexed: 12/30/2022]
Abstract
WHO estimated that nearly 1 million people become infected every day with any of four curable sexually transmitted infections (STIs): chlamydia, gonorrhoea, syphilis, and trichomoniasis. Despite their high global incidence, STIs remain a neglected area of research. In this Commission, we have prioritised five areas that represent particular challenges in STI treatment and control. Chlamydia remains the most commonly diagnosed bacterial STI in high-income countries despite widespread testing recommendations, sensitive and specific non-invasive testing techniques, and cheap effective therapy. We discuss the challenges for chlamydia control and evidence to support a shift from the current focus on infection-based screening to improved management of diagnosed cases and of chlamydial morbidity, such as pelvic inflammatory disease. The emergence and spread of antimicrobial resistance in Neisseria gonorrhoeae is globally recognised. We review current and potential future control and treatment strategies, with a focus on novel antimicrobials. Bacterial vaginosis is the most common vaginal disorder in women, but current treatments are associated with frequent recurrence. Recurrence after treatment might relate to evidence that suggests sexual transmission is integral to the pathogenesis of bacterial vaginosis, which has substantial implications for the development of effective management approaches. STIs disproportionately affect low-income and middle-income countries. We review strategies for case management, focusing on point-of-care tests that hold considerable potential for improving STI control. Lastly, STIs in men who have sex with men have increased since the late 1990s. We discuss the contribution of new biomedical HIV prevention strategies and risk compensation. Overall, this Commission aims to enhance the understanding of some of the key challenges facing the field of STIs, and outlines new approaches to improve the clinical management of STIs and public health.
Collapse
Affiliation(s)
- Magnus Unemo
- WHO Collaborating Centre for Gonorrhoea and Other Sexually Transmitted Infections, Faculty of Medicine and Health, Örebro University, Örebro, Sweden
| | - Catriona S Bradshaw
- Central Clinical School, Monash University, Melbourne, VIC, Australia; Melbourne Sexual Health Centre, Alfred Health, Melbourne, VIC, Australia
| | - Jane S Hocking
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, VIC, Australia
| | - Henry J C de Vries
- STI Outpatient Clinic, Public Health Service of Amsterdam, Amsterdam, Netherlands; Amsterdam Institute for Infection and Immunity, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands; Department of Dermatology, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Suzanna C Francis
- MRC Tropical Epidemiology Group, London School of Hygiene & Tropical Medicine, London, UK
| | - David Mabey
- Clinical Research Unit, London School of Hygiene & Tropical Medicine, London, UK
| | - Jeanne M Marrazzo
- Department of Medicine, University of Alabama School of Medicine, Birmingham, AL, USA
| | - Gerard J B Sonder
- Department of Infectious Diseases, Public Health Service of Amsterdam, Amsterdam, Netherlands; Division of Infectious Diseases, Department of Internal Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Jane R Schwebke
- Department of Medicine, University of Alabama School of Medicine, Birmingham, AL, USA
| | - Elske Hoornenborg
- STI Outpatient Clinic, Public Health Service of Amsterdam, Amsterdam, Netherlands
| | - Rosanna W Peeling
- Clinical Research Unit, London School of Hygiene & Tropical Medicine, London, UK
| | - Susan S Philip
- Disease Prevention and Control Population Health Division, San Francisco Department of Public Health, San Francisco, CA, USA
| | - Nicola Low
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
| | - Christopher K Fairley
- Central Clinical School, Monash University, Melbourne, VIC, Australia; Melbourne Sexual Health Centre, Alfred Health, Melbourne, VIC, Australia.
| |
Collapse
|
18
|
Sonkar SC, Sachdev D, Mishra PK, Kumar A, Mittal P, Saluja D. A molecular-beacon-based asymmetric PCR assay for easy visualization of amplicons in the diagnosis of trichomoniasis. Biosens Bioelectron 2016; 86:41-47. [DOI: 10.1016/j.bios.2016.06.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 05/18/2016] [Accepted: 06/09/2016] [Indexed: 10/21/2022]
|
19
|
Mashamba-Thompson TP, Sartorius B, Drain PK. Point-of-Care Diagnostics for Improving Maternal Health in South Africa. Diagnostics (Basel) 2016; 6:E31. [PMID: 27589808 PMCID: PMC5039565 DOI: 10.3390/diagnostics6030031] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Revised: 08/17/2016] [Accepted: 08/19/2016] [Indexed: 11/16/2022] Open
Abstract
Improving maternal health is a global priority, particularly in high HIV-endemic, resource-limited settings. Failure to use health care facilities due to poor access is one of the main causes of maternal deaths in South Africa. "Point-of-care" (POC) diagnostics are an innovative healthcare approach to improve healthcare access and health outcomes in remote and resource-limited settings. In this review, POC testing is defined as a diagnostic test that is carried out near patients and leads to rapid clinical decisions. We review the current and emerging POC diagnostics for maternal health, with a specific focus on the World Health Organization (WHO) quality-ASSURED (Affordability, Sensitivity, Specificity, User friendly, Rapid and robust, Equipment free and Delivered) criteria for an ideal point-of-care test in resource-limited settings. The performance of POC diagnostics, barriers and challenges related to implementing POC diagnostics for maternal health in rural and resource-limited settings are reviewed. Innovative strategies for overcoming these barriers are recommended to achieve substantial progress on improving maternal health outcomes in these settings.
Collapse
Affiliation(s)
- Tivani P Mashamba-Thompson
- Discipline of Public Health, School of Nursing and Public Health, University of KwaZulu-Natal, Durban 4001, South Africa.
| | - Benn Sartorius
- Discipline of Public Health, School of Nursing and Public Health, University of KwaZulu-Natal, Durban 4001, South Africa.
| | - Paul K Drain
- International Clinical Research Center, Department of Global Health, University of Washington, Seattle, WA 98195, USA.
- Division of Infectious Diseases, Department of Medicine, University of Washington, Seattle, WA 98195, USA.
- Department of Epidemiology, University of Washington, Seattle, WA 98195, USA.
- Department of Surgery, Massachusetts General Hospital, Boston, MA 02114, USA.
| |
Collapse
|
20
|
Poor Performance of the Chlamydia Rapid Test Device for the Detection of Asymptomatic Infections in South African Men: A Pilot Study. JOURNAL OF SEXUALLY TRANSMITTED DISEASES 2016; 2016:8695146. [PMID: 27195171 PMCID: PMC4853942 DOI: 10.1155/2016/8695146] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 03/30/2016] [Accepted: 04/05/2016] [Indexed: 11/17/2022]
Abstract
Background. To the best of our knowledge, there have been no published reports on the diagnostic performance of the Chlamydia Rapid Test (CRT) Device for male urine samples. We evaluated the performance of the CRT Device when compared with that of the BD ProbeTec ET PCR Assay in a population of asymptomatic men. Methods. The study enrolled 100 men between June and July 2015. From each consenting male, 20–30 mL of urine was collected. Sensitivity and specificity of the rapid test compared to PCR were calculated. All analysis was performed in STATA version 13. Results. All men had valid rapid and PCR test results. The test showed a low sensitivity against PCR (20%) (95% CI 3.7–6.2%); however, an excellent specificity was observed (100%) (one sided 97.5% CI: 96.0–100). Conclusions. This test was not found to be suitable as a screening tool for genital Chlamydia infections in men. Our findings emphasize the need for more sensitive POC tests to be developed since the current approach for the management of STIs in Africa is confounded by poor sensitivity and specificity resulting in many infected individuals not being treated.
Collapse
|
21
|
Mehra B, Bhattar S, Saxena S, Rawat D, Bhalla P. Evaluation of SD BIOLINE Syphilis 3.0 for Rapid Diagnosis of Syphilis: Report from a Regional Sexually Transmitted Infection Reference Laboratory in North India. J Lab Physicians 2016; 8:36-40. [PMID: 27013811 PMCID: PMC4785763 DOI: 10.4103/0974-2727.176239] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Background: Serology is considered the mainstay of syphilis diagnosis. The limitations of the traditional serological methods and the advent and availability of novel immunochromatographic assays have led to the widespread application of rapid point-of-care procedures as screening tools for syphilis. However, these tests have not been extensively evaluated. This study was designed to evaluate the performance of a rapid syphilis diagnostic test known as SD BIOLINE Syphilis 3.0 (SD Biostandard Diagnostics Private Limited, Gurgaon, Haryana, India). Materials and Methods: A panel comprising of 50 venereal disease research laboratory reactive and 50 nonreactive sera was tested using SD BIOLINE Syphilis 3.0. The performance of the test was evaluated using IMMUTREP Treponema pallidum hemagglutination assay (TPHA) (OMEGA Diagnostics Limited, Scotland, United Kingdom) as the reference standard and sensitivity, specificity, and negative and positive predictive values were calculated. Results: The sensitivity, specificity, and positive and negative predictive values of SD BIOLINE Syphilis 3.0 were 92.86% (confidence interval of 95%: 80.52–98.50%), 98.28% (90.76-99.96%), 97.50% (86.84–99.94%), and 95.00% (86.08–98.96%), respectively, compared to TPHA as the gold standard. Conclusion: Keeping in view the high sensitivity and specificity of SD BIOLINE Syphilis 3.0, we conclude that the test can be used as a tool for rapid on-site diagnosis of syphilis and as an alternative to TPHA for detection of antibodies to Treponema pallidum.
Collapse
Affiliation(s)
- Bhanu Mehra
- Department of Microbiology, Maulana Azad Medical College, New Delhi, India
| | - Sonali Bhattar
- Department of Microbiology, Maulana Azad Medical College, New Delhi, India
| | - Shikhar Saxena
- Department of Microbiology, Maulana Azad Medical College, New Delhi, India
| | - Deepti Rawat
- Department of Microbiology, Maulana Azad Medical College, New Delhi, India
| | - Preena Bhalla
- Department of Microbiology, Maulana Azad Medical College, New Delhi, India
| |
Collapse
|
22
|
Huang NL, Ye L, Schneider ME, Du YX, Xu YH, Fan LB, Du WD. Development of a novel protein biochip enabling validation of immunological assays and detection of serum IgG and IgM antibodies against Treponema pallidum pathogens in the patients with syphilis. Biosens Bioelectron 2015; 75:465-71. [PMID: 26364122 DOI: 10.1016/j.bios.2015.08.036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 08/05/2015] [Accepted: 08/18/2015] [Indexed: 01/03/2023]
Abstract
In this study, we developed a novel protein biochip methodology that was characterized by dithiobis (succinimidyl undecanoate) (DSU) and specialized for detection of serum IgG and IgM antibodies against Treponema pallidum pathogens in the patients with syphilis, respectively. The biochips were validated by a dimension of atomic force microscope (AFM). The visualized detection limit of IgG antibody on the biochip was 0.39μg/ml. Finally, 286 serum samples from the patients with syphilis were simultaneously tested on the rTpN15-17-47 coated biochips. The results were evaluated in comparison with the assays of T. pallidum particle agglutination (TPPA) and the toluidine red unheated serum test (TRUST). The result demonstrated that the relative positive rate in the 286 patients by biochip was 99.0%, similar to that by TPPA (97.9%, P>0.05) and higher than that by TRUST, (76.2%, P<0.01). The detection specificities were 100% for the biochip and the TPPA and 97.0% for the TRUST. Thus, the protein biochip would provide a useful platform not only for enabling concurrent detection of the infectious antibodies directed against T. pallidum on a larger scale, but also for monitoring therapy modality of the disease.
Collapse
Affiliation(s)
- Na-Li Huang
- Department of Biology, School of Life Sciences, Anhui Medical University, Hefei 230032, China
| | - Lei Ye
- Department of Biology, School of Life Sciences, Anhui Medical University, Hefei 230032, China
| | - Marion E Schneider
- Sektion Experimentelle Anaesthesiologie, Universitaetsklinikum Ulm, Ulm 89081, Germany
| | - Yi-Xin Du
- Sektion Experimentelle Anaesthesiologie, Universitaetsklinikum Ulm, Ulm 89081, Germany
| | - Yuan-Hong Xu
- Clinical Laboratory, the First Affiliated Hospital, Anhui Medical University, Hefei 230032, China
| | - Li-Bin Fan
- Department of Biology, School of Life Sciences, Anhui Medical University, Hefei 230032, China
| | - Wei-Dong Du
- Department of Biology, School of Life Sciences, Anhui Medical University, Hefei 230032, China; Sektion Experimentelle Anaesthesiologie, Universitaetsklinikum Ulm, Ulm 89081, Germany; Department of Pathology, Anhui Medical University, Hefei 230032, China.
| |
Collapse
|
23
|
Meyer T, Püschel K, Seifert D. Diagnostik sexuell übertragbarer Infektionen. Rechtsmedizin (Berl) 2014. [DOI: 10.1007/s00194-014-0992-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
24
|
Francis SC, Ao TT, Vanobberghen FM, Chilongani J, Hashim R, Andreasen A, Watson-Jones D, Changalucha J, Kapiga S, Hayes RJ. Epidemiology of curable sexually transmitted infections among women at increased risk for HIV in northwestern Tanzania: inadequacy of syndromic management. PLoS One 2014; 9:e101221. [PMID: 25025338 PMCID: PMC4099080 DOI: 10.1371/journal.pone.0101221] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 06/04/2014] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Curable, non-viral pathogens account for a significant burden of sexually transmitted infections (STIs), and there is established evidence that STIs increase both HIV acquisition and transmission. We investigated the prevalence, trends, and factors associated with Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis and Treponema pallidum, and the performance of syndromic management, among a cohort of women working in bars, hotels, and other food and recreational facilities near large-scale mines in northwestern Tanzania. METHODS HIV-negative women aged 18-44 years (N = 966) were enrolled and followed for 12 months in a microbicides feasibility study. We collected sociodemographic and behavioural data, performed clinical examinations, and tested for STIs, at enrolment and 3-monthly. Risk factors for STIs were investigated using logistic regression models with random effects. Sensitivity, specificity and predictive values of syndromic management were calculated. RESULTS At enrolment, the prevalences of C. trachomatis, N. gonorrhoeae, T. vaginalis, and high-titre active syphilis were 111/956 (12%), 42/955 (4%), 184/945 (19%) and 46/965 (5%), respectively. There were significant decreases over time for C. trachomatis and T. vaginalis (OR trend per month: 0.94 [95% CI 0.91, 0.97]; and 0.95 [0.93, 0.98], respectively; both p<0.001). The majority of these infections were not diagnosed by the corresponding syndrome; therefore, most participants were not treated at the diagnosis visit. Syndromic management was poorly predictive of laboratory-diagnosed infections. We identified a number of risk factors for STIs, including low educational level, some sexual behaviours, and ever having been pregnant. CONCLUSIONS This analysis demonstrates that the prevalences of curable STIs are high among women who work in food and recreational facilities in northwestern Tanzania. Most of these infections are missed by syndromic management. Accurate and affordable rapid-point-of-care tests and innovative interventions are needed to reduce the burden of STIs in this population which is at increased risk for HIV.
Collapse
Affiliation(s)
- Suzanna C. Francis
- MRC Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Mwanza Intervention Trials Unit, National Institute for Medical Research, Mwanza, Tanzania
| | - Trong T. Ao
- MRC Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Mwanza Intervention Trials Unit, National Institute for Medical Research, Mwanza, Tanzania
| | - Fiona M. Vanobberghen
- MRC Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Mwanza Intervention Trials Unit, National Institute for Medical Research, Mwanza, Tanzania
| | - Joseph Chilongani
- Mwanza Intervention Trials Unit, National Institute for Medical Research, Mwanza, Tanzania
- National Institute for Medical Research, Mwanza, Tanzania
| | - Ramadhan Hashim
- Mwanza Intervention Trials Unit, National Institute for Medical Research, Mwanza, Tanzania
| | - Aura Andreasen
- Mwanza Intervention Trials Unit, National Institute for Medical Research, Mwanza, Tanzania
- Clinical Research Department, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Deborah Watson-Jones
- Mwanza Intervention Trials Unit, National Institute for Medical Research, Mwanza, Tanzania
- Clinical Research Department, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - Saidi Kapiga
- MRC Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Mwanza Intervention Trials Unit, National Institute for Medical Research, Mwanza, Tanzania
| | - Richard J. Hayes
- MRC Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom
| |
Collapse
|
25
|
Tokel O, Inci F, Demirci U. Advances in plasmonic technologies for point of care applications. Chem Rev 2014; 114:5728-52. [PMID: 24745365 PMCID: PMC4086846 DOI: 10.1021/cr4000623] [Citation(s) in RCA: 215] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Indexed: 12/12/2022]
Affiliation(s)
- Onur Tokel
- Demirci
Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical
School, Cambridge, Massachusetts 02139, United States
| | - Fatih Inci
- Demirci
Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical
School, Cambridge, Massachusetts 02139, United States
- Demirci
Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Stanford University School of Medicine, Canary Center at Stanford
for Cancer Early Detection, Palo
Alto, California 94304, United States
| | - Utkan Demirci
- Demirci
Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical
School, Cambridge, Massachusetts 02139, United States
- Division of Infectious Diseases, Brigham
and Women’s Hospital, Harvard Medical
School, Boston, Massachusetts 02115, United States
- Harvard-MIT
Health Sciences and Technology, Cambridge, Massachusetts 02139, United States
- Demirci
Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Stanford University School of Medicine, Canary Center at Stanford
for Cancer Early Detection, Palo
Alto, California 94304, United States
| |
Collapse
|
26
|
McNerney R, Sollis K, Peeling RW. Improving access to new diagnostics through harmonised regulation: priorities for action. Afr J Lab Med 2014; 3:123. [PMID: 29043177 PMCID: PMC5637758 DOI: 10.4102/ajlm.v3i1.123] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Accepted: 11/15/2013] [Indexed: 11/25/2022] Open
Abstract
A new generation of diagnostic tests is being developed for use at the point of care that could save lives and reduce the spread of infectious diseases through early detection and treatment. It is important that patients in developing countries have access to these products at affordable prices and without delay. Regulation of medical products is intended to ensure safety and quality whilst balancing the need for timely access to beneficial new products. Current regulatory oversight of diagnostic tests in developing countries is highly variable and weak regulation allows poor-quality tests to enter the market. However, inefficient or overzealous regulation results in unnecessary delays, increases costs and acts as a barrier to innovation and market entry. Setting international standards and streamlining the regulatory process could reduce these barriers. Four priority activities have been identified where convergence of standards and protocols or joint review of data would be advantageous: (1) adoption of a common registration file for pre-market approval; (2) convergence of quality standards for manufacturing site inspections; (3) use of common evaluation protocols, as well as joint review of data, to reduce unnecessary duplication of lengthy and costly clinical performance studies; and (4) use of networks of laboratories for post-market surveillance in order to monitor ongoing quality of diagnostic devices. The adoption and implementation of such measures in developing countries could accelerate access to new diagnostic tests that are safe and affordable.
Collapse
Affiliation(s)
- Ruth McNerney
- London School of Hygiene & Tropical Medicine, United Kingdom
| | - Kimberly Sollis
- London School of Hygiene & Tropical Medicine, United Kingdom
| | | |
Collapse
|
27
|
Poor Reporting of Outcomes Beyond Accuracy in Point-of-Care Tests for Syphilis: A Call for a Framework. AIDS Res Treat 2014; 2014:465932. [PMID: 24795821 PMCID: PMC3985157 DOI: 10.1155/2014/465932] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 02/23/2014] [Accepted: 02/27/2014] [Indexed: 11/24/2022] Open
Abstract
Background. Point-of-care (POC) diagnostics for syphilis can contribute to epidemic control by offering a timely knowledge of serostatus. Although accuracy data on POC syphilis tests have been widely published, few studies have evaluated broader outcomes beyond accuracy that impact patients and health systems. We comprehensively reviewed evidence and reporting of these implementation research outcomes (IROs), and proposed a framework to improve their quality. Methods. Three reviewers systematically searched 6 electronic databases from 1980 to 2014 for syphilis POC studies reporting IROs. Data were abstracted and findings synthesised narratively. Results. Of 71 studies identified, 38 documented IROs. IROs were subclassified into preference (7), acceptability (15), feasibility (15), barriers and challenges (15), impact (13), and prevalence (23). Using our framework and definitions, a pattern of incomplete documentation, inconsistent definitions, and lack of clarity was identified across all IROs. Conclusion. Although POC screening tests for syphilis were generally favourably evaluated across a range of outcomes, the quality of evidence was compromised by inconsistent definitions, poor methodology, and documentation of outcomes. A framework for standardized reporting of outcomes beyond accuracy was proposed and considered a necessary first step towards an effective implementation of these metrics in POC diagnostics research.
Collapse
|
28
|
Micro-a-fluidics ELISA for rapid CD4 cell count at the point-of-care. Sci Rep 2014; 4:3796. [PMID: 24448112 PMCID: PMC3898414 DOI: 10.1038/srep03796] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 12/20/2013] [Indexed: 11/09/2022] Open
Abstract
HIV has become one of the most devastating pathogens in human history. Despite fast progress in HIV-related basic research, antiretroviral therapy (ART) remains the most effective method to save AIDS patients' lives. Unfortunately, ART cannot be universally accessed, especially in developing countries, due to the lack of effective treatment monitoring diagnostics. Here, we present an inexpensive, rapid and portable micro-a-fluidic platform, which can streamline the process of an enzyme-linked immunosorbent assay (ELISA) in a fully automated manner for CD4 cell count. The micro-a-fluidic CD4 cell count is achieved by eliminating operational fluid flow via “moving the substrate”, as opposed to “flowing liquid” in traditional ELISA or microfluidic methods. This is the first demonstration of capturing and detecting cells from unprocessed whole blood using the enzyme-linked immunosorbent assay (ELISA) in a microfluidic channel. Combined with cell phone imaging, the presented micro-a-fluidic ELISA platform holds great promise for offering rapid CD4 cell count to scale up much needed ART in resource-constrained settings. The developed system can be extended to multiple areas for ELISA-related assays.
Collapse
|
29
|
Feasibility and Field Performance of a Simultaneous Syphilis and HIV Point-of-Care Test Based Screening Strategy in at Risk Populations in Edmonton, Canada. AIDS Res Treat 2013; 2013:819593. [PMID: 24527210 PMCID: PMC3914585 DOI: 10.1155/2013/819593] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Accepted: 11/13/2013] [Indexed: 11/17/2022] Open
Abstract
Few studies have evaluated the feasibility of delivering syphilis point-of-care (POC) testing in outreach (nonclinical) settings in resource rich countries. The objectives of the study were to evaluate the feasibility and diagnostic performance of performing both HIV and syphilis POC testing in outreach settings and to document new cases identified in the study population. 1,265 outreach testing visits were offered syphilis and HIV POC testing and 81.5% (n = 1,031) consented to testing. In our population, the SD Bioline 3.0 Syphilis Test had a sensitivity of 85.3% [CI (68.9-95.0)], specificity of 100.0% [CI (99.6-100.0)], positive predictive value (PPV) of 100.0% [CI (88.1-100.0)], and negative predictive value (NPV) of 99.5% [CI (98.9-99.8)]. Test characteristics for the INSTI HIV-1/HIV-2 Antibody Test had a 100.0% sensitivity [CI (39.8-100.00], 99.8 specificity [CI (99.3-100)], 66.7% PPV [CI (22.3-95.7)], and 100.0% NPV [CI (99.6-100.0)]. Four new cases of syphilis and four new HIV cases were diagnosed. In summary, at risk population seeking STI testing found POC tests to be acceptable, the POC tests performed well in outreach settings, and new cases of syphilis and HIV were identified and linked to treatment and care.
Collapse
|
30
|
Characterizing the intracellular distribution of metabolites in intact Chlamydia-infected cells by Raman and two-photon microscopy. Microbes Infect 2013; 15:461-9. [PMID: 23541981 DOI: 10.1016/j.micinf.2013.03.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Revised: 02/17/2013] [Accepted: 03/17/2013] [Indexed: 11/24/2022]
Abstract
Chlamydia species are obligate intracellular pathogens that proliferate only within infected cells. Currently, there are no known techniques or systems that can probe the spatial distribution of metabolites of interest within intact Chlamydia-infected cells. Here we investigate the ability of Raman microscopy to probe the chemical composition of different compartments (nucleus, inclusion, and cytoplasm) of Chlamydia trachomatis-infected epithelial cells. The overall intensity of the Raman spectrum is greatest in the inclusions and lowest in the cytoplasm in fixed cells. Difference spectra generated by normalizing to the intensity of the strong 1004 cm(-1) phenylalanine line show distinct differences among the three compartments. Most notably, the concentrations of adenine are greater in both the inclusions and the nucleus than in the cytoplasm, as seen by Raman microscopy. The source of the adenine was explored through a complementary approach, using two-photon microscopy imaging. Autofluorescence measurements of living, infected cells show that the adenine-containing molecules, NAD(P)H and FAD, are present mainly in the cytoplasm, suggesting that these molecules are not the source of the additional adenine signal in the nucleus and inclusions. Experiments of infected cells stained with a DNA-binding dye, Hoechst 33258, reveal that most of the DNA is present in the nucleus and the inclusions, suggesting that DNA/RNA is the main source of the additional Raman adenine signal in the nucleus and inclusions. Thus, Raman and two-photon microscopy are among the few non-invasive methods available to investigate cells infected with Chlamydia and, together, should also be useful for studying infection by other intracellular pathogens that survive within intracellular vacuoles.
Collapse
|
31
|
Jafari Y, Peeling RW, Shivkumar S, Claessens C, Joseph L, Pai NP. Are Treponema pallidum specific rapid and point-of-care tests for syphilis accurate enough for screening in resource limited settings? Evidence from a meta-analysis. PLoS One 2013; 8:e54695. [PMID: 23468842 PMCID: PMC3582640 DOI: 10.1371/journal.pone.0054695] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2012] [Accepted: 12/17/2012] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Rapid and point-of-care (POC) tests for syphilis are an invaluable screening tool, yet inadequate evaluation of their diagnostic accuracy against best reference standards limits their widespread global uptake. To fill this gap, a systematic review and meta-analysis was conducted to evaluate the sensitivity and specificity of rapid and POC tests in blood and serum samples against Treponema pallidum (TP) specific reference standards. METHODS Five electronic databases (1980-2012) were searched, data was extracted from 33 articles, and Bayesian hierarchical models were fit. RESULTS In serum samples, against a TP specific reference standard point estimates with 95% credible intervals (CrI) for the sensitivities of popular tests were: i) Determine, 90.04% (80.45, 95.21), ii) SD Bioline, 87.06% (75.67, 94.50), iii) VisiTect, 85.13% (72.83, 92.57), and iv) Syphicheck, 74.48% (56.85, 88.44), while specificities were: i) Syphicheck, 99.14% (96.37, 100), ii) Visitect, 96.45% (91.92, 99.29), iii) SD Bioline, 95.85% (89.89, 99.53), and iv) Determine, 94.15% (89.26, 97.66). In whole blood samples, sensitivities were: i) Determine, 86.32% (77.26, 91.70), ii) SD Bioline, 84.50% (78.81, 92.61), iii) Syphicheck, 74.47% (63.94, 82.13), and iv) VisiTect, 74.26% (53.62, 83.68), while specificities were: i) Syphicheck, 99.58% (98.91, 99.96), ii) VisiTect, 99.43% (98.22, 99.98), iii) SD Bioline, 97.95%(92.54, 99.33), and iv) Determine, 95.85% (92.42, 97.74). CONCLUSIONS Rapid and POC treponemal tests reported sensitivity and specificity estimates comparable to laboratory-based treponemal tests. In resource limited settings, where access to screening is limited and where risk of patients lost to follow up is high, the introduction of these tests has already been shown to improve access to screening and treatment to prevent stillbirths and neonatal mortality due to congenital syphilis. Based on the evidence, it is concluded that rapid and POC tests are useful in resource limited settings with poor access to laboratories or screening for syphilis.
Collapse
Affiliation(s)
- Yalda Jafari
- Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montréal, Canada
| | | | - Sushmita Shivkumar
- Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montréal, Canada
| | | | - Lawrence Joseph
- Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montréal, Canada
- Division of Clinical Epidemiology, Department of Medicine, McGill University and MUHC, Montréal, Canada
| | - Nitika Pant Pai
- Division of Clinical Epidemiology, Department of Medicine, McGill University and MUHC, Montréal, Canada
- * E-mail:
| |
Collapse
|
32
|
Pai NP, Kurji J, Singam A, Barick R, Jafari Y, Klein MB, Chhabra S, Shivkumar P. Simultaneous triple point-of-care testing for HIV, syphilis and hepatitis B virus to prevent mother-to-child transmission in India. Int J STD AIDS 2012; 23:319-24. [PMID: 22648884 DOI: 10.1258/ijsa.2011.011139] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
An innovative simultaneous triple point-of-care (STPOC) screening strategy for syphilis, hepatitis B and HIV with Determine(®) tests was offered to pregnant women presenting for antenatal care and evaluated for feasibility and preference in rural India. Of 1066 participants approached, 1046 consented, of which 1002 (96.0%) completed the strategy. Only 9% reported any history of testing in their current pregnancy. With STPOC screening, 989 women (98.7%) tested negative and 13 had preliminary positive results for infection. The total time taken was 45 minutes per participant. Mothers and infants were provided prophylaxis/treatment for HIV, syphilis and hepatitis B, with interventions initiated within 3-5 days. STPOC was preferred by 99.3% (95%CI: 98.8-99.8%) of participants, facilitated early simultaneous screening for the three infections, timely initiation of prophylaxis/treatment and was feasible in this rural setting. These data suggest that multiplexed STPOC screening for syphilis, hepatitis B and HIV in pregnancy would be desirable for women in rural India.
Collapse
Affiliation(s)
- N P Pai
- Division of Clinical Epidemiology & Division of Infectious Diseases, McGill University Health Center, Montreal, Quebec, Canada.
| | | | | | | | | | | | | | | |
Collapse
|
33
|
Design and development of an in-house multiplex RT-PCR assay for simultaneous detection of HIV-1 and HCV in plasma samples. IRANIAN JOURNAL OF MICROBIOLOGY 2012; 52:456-63. [PMID: 22783455 DOI: 10.1007/s12088-012-0271-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2011] [Accepted: 04/26/2012] [Indexed: 01/12/2023]
Abstract
BACKGROUND AND OBJECTIVES HIV-1 and HCV infections are life threatening problems in patients who receive blood products. Serological methods have proven useful in detecting these infections, but there are setbacks that make it challenging to detect these infectious agents. By the advent of Nucleic Acid Testing (NAT) methods, especially in multiplex format, more precise detection is possible. MATERIALS AND METHODS We have developed a multiplex RT-PCR assay for simultaneous detection of HIV-1 and HCV. Primers were designed for highly conserved region of genome of each virus. Using these primers and standard plasmids, we determined the limit of detection, clinical and analytical specificity and sensitivity of the assay. Monoplex and multiplex RT-PCR were performed. RESULTS Analytical sensitivity was considered to be 100 and 200 copies/ml for HIV-1 and HCV, respectively. High concentration of one virus had no significant effect on the detection of the other one with low concentration. By analysis of 40 samples, clinical sensitivity of the assay was determined to be 97.5%. Using different viral and human genome samples, the specificity of the assay was evaluated to be 100%. CONCLUSIONS The aim of this study was to develop a reliable, rapid and cost effective method to detect HIV-1 and HCV simultaneously. Results showed that this simple and rapid method is perfectly capable of detecting two viruses in clinical samples.
Collapse
|
34
|
Chen CY, Pillay A. Protocol for the detection of Treponema pallidum in paraffin-embedded specimens. Methods Mol Biol 2012; 903:295-306. [PMID: 22782827 DOI: 10.1007/978-1-61779-937-2_20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Formalin-fixed paraffin-embedded (FFPE) tissue blocks are routinely used for histopathological examination and are also useful for specific pathogen detection by polymerase chain reaction (PCR). FFPE tissue is stable at ambient temperature for an extended period of time and relatively easy to transport compared to fresh tissue, which has to be processed or frozen immediately. In addition, archival material is an invaluable source for retrospective molecular and clinical investigation. This chapter describes detailed procedures for nucleic acid extraction and PCR detection of Treponema pallidum using FFPE tissue.
Collapse
Affiliation(s)
- Cheng-Yen Chen
- Laboratory Reference and Research Branch, Division of STD Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD and Tuberculosis Prevention, Centers for Disease Control and Prevention, Atlanta, GA, USA.
| | | |
Collapse
|
35
|
LaBarre P, Hawkins KR, Gerlach J, Wilmoth J, Beddoe A, Singleton J, Boyle D, Weigl B. A simple, inexpensive device for nucleic acid amplification without electricity-toward instrument-free molecular diagnostics in low-resource settings. PLoS One 2011; 6:e19738. [PMID: 21573065 PMCID: PMC3090398 DOI: 10.1371/journal.pone.0019738] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Accepted: 04/14/2011] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Molecular assays targeted to nucleic acid (NA) markers are becoming increasingly important to medical diagnostics. However, these are typically confined to wealthy, developed countries; or, to the national reference laboratories of developing-world countries. There are many infectious diseases that are endemic in low-resource settings (LRS) where the lack of simple, instrument-free, NA diagnostic tests is a critical barrier to timely treatment. One of the primary barriers to the practicality and availability of NA assays in LRS has been the complexity and power requirements of polymerase chain reaction (PCR) instrumentation (another is sample preparation). METHODOLOGY/PRINCIPAL FINDINGS In this article, we investigate the hypothesis that an electricity-free heater based on exothermic chemical reactions and engineered phase change materials can successfully incubate isothermal NA amplification assays. We assess the heater's equivalence to commercially available PCR instruments through the characterization of the temperature profiles produced, and a minimal method comparison. Versions of the prototype for several different isothermal techniques are presented. CONCLUSIONS/SIGNIFICANCE We demonstrate that an electricity-free heater based on exothermic chemical reactions and engineered phase change materials can successfully incubate isothermal NA amplification assays, and that the results of those assays are not significantly different from ones incubated in parallel in commercially available PCR instruments. These results clearly suggest the potential of the non-instrumented nucleic acid amplification (NINA) heater for molecular diagnostics in LRS. When combined with other innovations in development that eliminate power requirements for sample preparation, cold reagent storage, and readout, the NINA heater will comprise part of a kit that should enable electricity-free NA testing for many important analytes.
Collapse
Affiliation(s)
- Paul LaBarre
- PATH, Seattle, Washington, United States of America.
| | | | | | | | | | | | | | | |
Collapse
|
36
|
Peeling RW, Ronald A. Diagnostic challenges of sexually transmitted infections in resource-limited settings. Future Microbiol 2009; 4:1271-82. [DOI: 10.2217/fmb.09.100] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The global burden of sexually transmitted infections (STIs) is highest in the developing world where access to laboratory services is limited. Sophisticated laboratory diagnostic tests using noninvasive specimens have enabled developed countries to screen and diagnose curable STIs in a variety of settings, but control programs in resource-limited settings continue to struggle to find simple rapid tests that can provide adequate performance in the absence of laboratory services. While recent technological advances and investments in research and development may soon yield improved STI tests that can make an impact, these tests will need to be deployed within a health system that includes: regulatory oversight, quality assurance, good supply-chain management, effective training, information systems and a sound surveillance system to monitor disease trends, inform policy decisions and assess the impact of interventions.
Collapse
Affiliation(s)
- Rosanna W Peeling
- London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Allan Ronald
- International Center for Infectious Diseases, 403-445 Ellice Ave., Winnipeg Manitoba, Canada R3B3P5
| |
Collapse
|
37
|
Marangoni A, Moroni A, Accardo S, Cevenini R. Laboratory diagnosis of syphilis with automated immunoassays. J Clin Lab Anal 2009; 23:1-6. [PMID: 19140205 DOI: 10.1002/jcla.20268] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The serological detection of specific antibodies to Treponema pallidum is of particular importance in the diagnosis of syphilis. The purpose of this study was to evaluate diagnostic performances of automated immunoassays in comparison with T. pallidum hemagglutination test (TPHA) and Western Blot (WB). The retrospective study was performed with different panels of sera: 244 clinical and serological characterized syphilitic sera and 203 potentially interfering samples. All the sera were tested by Enzygnost Syphilis, ARCHITECT Syphilis TP, TPHA, and homemade WB. The diagnostic performances of the two assays were very similar: both Enzygnost Syphilis and ARCHITECT Syphilis TP performed with a sensitivity of 99.2%, whereas the specificity was 98.5 and 98.4%, respectively. Considering the suitability for automation, both immunoassays may represent a good choice as a screening test. However, the use of a confirmatory test, such as TPHA or WB, remains a must in order to avoid false-positive results.
Collapse
Affiliation(s)
- Antonella Marangoni
- Dipartimento di Ematologia e Sc. Oncologiche, Section of Microbiology, St. Orsola Hospital, University of Bologna, Bologna, Italy.
| | | | | | | |
Collapse
|
38
|
|