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Calderaro A, Piccolo G, Chezzi C. The Laboratory Diagnosis of Malaria: A Focus on the Diagnostic Assays in Non-Endemic Areas. Int J Mol Sci 2024; 25:695. [PMID: 38255768 PMCID: PMC10815132 DOI: 10.3390/ijms25020695] [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: 11/20/2023] [Revised: 12/26/2023] [Accepted: 01/03/2024] [Indexed: 01/24/2024] Open
Abstract
Even if malaria is rare in Europe, it is a medical emergency and programs for its control should ensure both an early diagnosis and a prompt treatment within 24-48 h from the onset of the symptoms. The increasing number of imported malaria cases as well as the risk of the reintroduction of autochthonous cases encouraged laboratories in non-endemic countries to adopt diagnostic methods/algorithms. Microscopy remains the gold standard, but with limitations. Rapid diagnostic tests have greatly expanded the ability to diagnose malaria for rapid results due to simplicity and low cost, but they lack sensitivity and specificity. PCR-based assays provide more relevant information but need well-trained technicians. As reported in the World Health Organization Global Technical Strategy for Malaria 2016-2030, the development of point-of-care testing is important for the improvement of diagnosis with beneficial consequences for prompt/accurate treatment and for preventing the spread of the disease. Despite their limitations, diagnostic methods contribute to the decline of malaria mortality. Recently, evidence suggested that artificial intelligence could be utilized for assisting pathologists in malaria diagnosis.
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Affiliation(s)
- Adriana Calderaro
- Department of Medicine and Surgery, University of Parma, Viale A. Gramsci 14, 43126 Parma, Italy; (G.P.); (C.C.)
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Ansah F, Nyame K, Laryea R, Owusu R, Amon D, Boyetey MJB, Ayeke D, Razak N, Kornu VE, Ashitei S, Owusu-Appiah C, Chirawurah JD, Abugri J, Aniweh Y, Opoku N, Sutherland CJ, Binka FN, Kweku M, Awandare GA, Dinko B. The temporal dynamics of Plasmodium species infection after artemisinin-based combination therapy (ACT) among asymptomatic children in the Hohoe municipality, Ghana. Malar J 2023; 22:271. [PMID: 37710288 PMCID: PMC10500816 DOI: 10.1186/s12936-023-04712-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 09/11/2023] [Indexed: 09/16/2023] Open
Abstract
BACKGROUND The routine surveillance of asymptomatic malaria using nucleic acid-based amplification tests is essential in obtaining reliable data that would inform malaria policy formulation and the implementation of appropriate control measures. METHODS In this study, the prevalence rate and the dynamics of Plasmodium species among asymptomatic children (n = 1697) under 5 years from 30 communities within the Hohoe municipality in Ghana were determined. RESULTS AND DISCUSSION The observed prevalence of Plasmodium parasite infection by polymerase chain reaction (PCR) was 33.6% (571/1697), which was significantly higher compared to that obtained by microscopy [26.6% (451/1697)] (P < 0.0001). Based on species-specific analysis by nested PCR, Plasmodium falciparum infection [33.6% (570/1697)] was dominant, with Plasmodium malariae, Plasmodium ovale and Plasmodium vivax infections accounting for 0.1% (1/1697), 0.0% (0/1697), and 0.0% (0/1697), respectively. The prevalence of P. falciparum infection among the 30 communities ranged from 0.0 to 82.5%. Following artesunate-amodiaquine (AS + AQ, 25 mg/kg) treatment of a sub-population of the participants (n = 184), there was a substantial reduction in Plasmodium parasite prevalence by 100% and 79.2% on day 7 based on microscopy and nested PCR analysis, respectively. However, there was an increase in parasite prevalence from day 14 to day 42, with a subsequent decline on day 70 by both microscopy and nested PCR. For parasite clearance rate analysis, we found a significant proportion of the participants harbouring residual Plasmodium parasites or parasite genomic DNA on day 1 [65.0% (13/20)], day 2 [65.0% (13/20)] and day 3 [60.0% (12/20)] after initiating treatment. Of note, gametocyte carriage among participants was low before and after treatment. CONCLUSION Taken together, the results indicate that a significant number of individuals could harbour residual Plasmodium parasites or parasite genomic DNA after treatment. The study demonstrates the importance of routine surveillance of asymptomatic malaria using sensitive nucleic acid-based amplification techniques.
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Affiliation(s)
- Felix Ansah
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), College of Basic and Applied Sciences, University of Ghana, Legon, Accra, Ghana
- Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Legon, Accra, Ghana
| | - Kwamina Nyame
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), College of Basic and Applied Sciences, University of Ghana, Legon, Accra, Ghana
- Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Legon, Accra, Ghana
| | - Rukaya Laryea
- Department of Epidemiology and Biostatistics, Fred Newton Binka School of Public Health, University of Health and Allied Sciences, Hohoe, Ghana
| | - Richard Owusu
- Department of Epidemiology and Biostatistics, Fred Newton Binka School of Public Health, University of Health and Allied Sciences, Hohoe, Ghana
| | - Denick Amon
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), College of Basic and Applied Sciences, University of Ghana, Legon, Accra, Ghana
| | - Mark-Jefferson Buer Boyetey
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), College of Basic and Applied Sciences, University of Ghana, Legon, Accra, Ghana
| | - Dzidzor Ayeke
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), College of Basic and Applied Sciences, University of Ghana, Legon, Accra, Ghana
| | - Nasibatu Razak
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), College of Basic and Applied Sciences, University of Ghana, Legon, Accra, Ghana
| | - Victor E Kornu
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), College of Basic and Applied Sciences, University of Ghana, Legon, Accra, Ghana
| | - Sarah Ashitei
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), College of Basic and Applied Sciences, University of Ghana, Legon, Accra, Ghana
| | - Caleb Owusu-Appiah
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), College of Basic and Applied Sciences, University of Ghana, Legon, Accra, Ghana
| | - Jersley D Chirawurah
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), College of Basic and Applied Sciences, University of Ghana, Legon, Accra, Ghana
- Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Legon, Accra, Ghana
| | - James Abugri
- Department of Biochemistry and Forensic Sciences, School of Chemical and Biochemical Sciences, C. K. Tedam University of Technology and Applied Sciences, Navrongo, Ghana
| | - Yaw Aniweh
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), College of Basic and Applied Sciences, University of Ghana, Legon, Accra, Ghana
| | - Nicholas Opoku
- Department of Epidemiology and Biostatistics, Fred Newton Binka School of Public Health, University of Health and Allied Sciences, Hohoe, Ghana
| | - Colin J Sutherland
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Fred N Binka
- Department of Epidemiology and Biostatistics, Fred Newton Binka School of Public Health, University of Health and Allied Sciences, Hohoe, Ghana
| | - Margaret Kweku
- Department of Epidemiology and Biostatistics, Fred Newton Binka School of Public Health, University of Health and Allied Sciences, Hohoe, Ghana
| | - Gordon A Awandare
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), College of Basic and Applied Sciences, University of Ghana, Legon, Accra, Ghana
- Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Legon, Accra, Ghana
| | - Bismarck Dinko
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK.
- Department of Biomedical Sciences, School of Basic and Biomedical Sciences, University of Health and Allied Sciences, Ho, Ghana.
- Department of Clinical Microbiology, School of Medicine and Dentistry College of Health Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ashanti Region, Ghana.
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Firdaus ER, Park JH, Muh F, Lee SK, Han JH, Lim CS, Na SH, Park WS, Park JH, Han ET. Performance Evaluation of Biozentech Malaria Scanner in Plasmodium knowlesi and P. falciparum as a New Diagnostic Tool. THE KOREAN JOURNAL OF PARASITOLOGY 2021; 59:113-119. [PMID: 33951766 PMCID: PMC8106981 DOI: 10.3347/kjp.2021.59.2.113] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 03/11/2021] [Indexed: 12/21/2022]
Abstract
The computer vision diagnostic approach currently generates several malaria diagnostic tools. It enhances the accessible and straightforward diagnostics that necessary for clinics and health centers in malaria-endemic areas. A new computer malaria diagnostics tool called the malaria scanner was used to investigate living malaria parasites with easy sample preparation, fast and user-friendly. The cultured Plasmodium parasites were used to confirm the sensitivity of this technique then compared to fluorescence-activated cell sorting (FACS) analysis and light microscopic examination. The measured percentage of parasitemia by the malaria scanner revealed higher precision than microscopy and was similar to FACS. The coefficients of variation of this technique were 1.2–6.7% for Plasmodium knowlesi and 0.3–4.8% for P. falciparum. It allowed determining parasitemia levels of 0.1% or higher, with coefficient of variation smaller than 10%. In terms of the precision range of parasitemia, both high and low ranges showed similar precision results. Pearson’s correlation test was used to evaluate the correlation data coming from all methods. A strong correlation of measured parasitemia (r2=0.99, P<0.05) was observed between each method. The parasitemia analysis using this new diagnostic tool needs technical improvement, particularly in the differentiation of malaria species.
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Affiliation(s)
- Egy Rahman Firdaus
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon 24341, Korea
| | - Ji-Hoon Park
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon 24341, Korea
| | - Fauzi Muh
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon 24341, Korea
| | - Seong-Kyun Lee
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon 24341, Korea
| | - Jin-Hee Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon 24341, Korea
| | - Chae-Seung Lim
- Department of Laboratory Medicine, Korea University College of Medicine, Seoul 08308, Korea
| | - Sung-Hun Na
- Department of Obstetrics and Gynecology, Kangwon National University Hospital, Kangwon National University School of Medicine, Chuncheon 24341, Korea
| | - Won Sun Park
- Department of Physiology, School of Medicine, Kangwon National University, Chuncheon 24341, Korea
| | - Jeong-Hyun Park
- Department of Anatomy and Cell Biology, School of Medicine, Kangwon National University, Chuncheon 24341, Korea
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon 24341, Korea
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Yoon J, Jang WS, Nam J, Mihn DC, Lim CS. An Automated Microscopic Malaria Parasite Detection System Using Digital Image Analysis. Diagnostics (Basel) 2021; 11:diagnostics11030527. [PMID: 33809642 PMCID: PMC8002244 DOI: 10.3390/diagnostics11030527] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 02/26/2021] [Accepted: 03/15/2021] [Indexed: 10/26/2022] Open
Abstract
Rapid diagnosis and parasitemia measurement is crucial for management of malaria. Microscopic examination of peripheral blood (PB) smears is the gold standard for malaria detection. However, this method is labor-intensive. Here, we aimed to develop a completely automated microscopic system for malaria detection and parasitemia measurement. The automated system comprises a microscope, plastic chip, fluorescent dye, and an image analysis program. Analytical performance was evaluated regarding linearity, precision, and limit of detection and was compared with that of conventional microscopic PB smear examination and flow cytometry. The automated microscopic malaria parasite detection system showed a high degree of linearity for Plasmodium falciparum culture (R2 = 0.958, p = 0.005) and Plasmodium vivax infected samples (R2 = 0.931, p = 0.008). Precision was defined as the %CV of the assay results at each level of parasitemia and the %CV value for our system was lower than that for microscopic examination for all densities of parasitemia. The limit of detection analysis showed 95% probability for parasite detection was 0.00066112%, and a high correlation was observed among all three methods. The sensitivity and specificity of the system was both 100% (n = 21/21) and 100% (n = 50/50), respectively, and the system correctly identified all P. vivax and P. falciparum samples. The automated microscopic malaria parasite detection system offers several advantages over conventional microscopy for rapid diagnosis and parasite density monitoring of malaria.
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Affiliation(s)
- Jung Yoon
- Department of Laboratory Medicine, Korea University College of Medicine, Seoul 08308, Korea; (J.Y.); (W.S.J.)
| | - Woong Sik Jang
- Department of Laboratory Medicine, Korea University College of Medicine, Seoul 08308, Korea; (J.Y.); (W.S.J.)
| | - Jeonghun Nam
- Department of Song-Do Bio-Environmental Engineering, Incheon Jaeneung University, Incheon 21987, Korea;
| | - Do-CiC Mihn
- Department of Diagnostic Immunology, Seegene Medical Foundation, Seoul 04805, Korea;
| | - Chae Seung Lim
- Department of Laboratory Medicine, Korea University College of Medicine, Seoul 08308, Korea; (J.Y.); (W.S.J.)
- Correspondence: ; Tel.: +82-2-2626-3245
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Gitta B, Kilian N. Diagnosis of Malaria Parasites Plasmodium spp. in Endemic Areas: Current Strategies for an Ancient Disease. Bioessays 2019; 42:e1900138. [PMID: 31830324 DOI: 10.1002/bies.201900138] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 11/05/2019] [Indexed: 12/14/2022]
Abstract
Fast and effective detection of the causative agent of malaria in humans, protozoan Plasmodium parasites, is of crucial importance for increasing the effectiveness of treatment and to control a devastating disease that affects millions of people living in endemic areas. The microscopic examination of Giemsa-stained blood films still remains the gold-standard in Plasmodium detection today. However, there is a high demand for alternative diagnostic methods that are simple, fast, highly sensitive, ideally do not rely on blood-drawing and can potentially be conducted by the patients themselves. Here, the history of Plasmodium detection is discussed, and advantages and disadvantages of diagnostic methods that are currently being applied are assessed.
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Affiliation(s)
- Brian Gitta
- Matibabu, 120 Semawata Rd, Ntinda, Kampala, 00256, Uganda
| | - Nicole Kilian
- Centre for Infectious Diseases, Parasitology Heidelberg University Hospital, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany
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Diagnostic performance of CellaVision DM96 for Plasmodium vivax and Plasmodium falciparum screening in peripheral blood smears. Acta Trop 2019; 193:7-11. [PMID: 30768978 DOI: 10.1016/j.actatropica.2019.02.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 11/24/2018] [Accepted: 02/11/2019] [Indexed: 12/18/2022]
Abstract
Microscopic examination of blood smears is the standard method for malaria diagnosis but is labor-intensive and requires expert staff. CellaVision DM96 (CellaVision, Lund, Sweden) is a digital hematology analyzer available for advanced morphological analysis of blood films including intracellular parasites. Here, we evaluated the CellaVision DM96 Advanced RBC Application for malaria detection in stained peripheral blood (PB) smears. Two hundred and twenty thin PB smear slides (84 P. vivax, 14 P. falciparum, 122 negative controls) were stained with Wright-Giemsa using automated slidemaker/strainers of Beckman Coulter hematology systems (LH780, Beckman Coulter Inc., Miami, FL). The slides were automatically analyzed by CellaVision, and images were manually reviewed by experts. The results of automatic and manual detection by CellaVision were compared to those of microscopic examination. The sensitivity and specificity of automatic detection by CellaVision were 23.5% (23/98) and 81.1% (99/122), respectively. When CellaVision images were manually reviewed, the sensitivity and specificity increased to 65.3% (64/98) and 90.2% (110/122), respectively. The detection of P. falciparum showed the highest sensitivity by both the automated (33.3%) and the manual (85.7%) method. CellaVision misinterpreted malaria parasites as Howell-Jolly bodies in 57.1%, as Pappenheimer bodies in 84.7%, and as basophilic stipplings in 75.5% of the slides. Malaria diagnosis using CellaVision DM96 requires further improvements. Manual review improves CellaVision performance, but confirmation by conventional microscopy remains essential.
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Jemere KA, Melaku MY, Jemeber TH, Abate MA. Performance evaluation of laboratory professionals on malaria microscopy at health facilities in Bahir Dar city administration, Northwest Ethiopia. PLoS One 2018; 13:e0203420. [PMID: 30335752 PMCID: PMC6193612 DOI: 10.1371/journal.pone.0203420] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2018] [Accepted: 08/21/2018] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Microscopic diagnosis of Giemsa stained thick and thin blood films by skilled microscopists has remained the gold standard laboratory method for the diagnosis of malaria. However, there is a scarcity of qualified laboratory professionals for correctly diagnosing malaria using microscopy. The aim of this study was to evaluate the performance of laboratory professionals on malaria microscopy at health facilities in Bahir Dar city administration, Northwest Ethiopia. METHODS A cross-sectional study was conducted from January to March 2017 in Bahir Dar City. A total of 87 laboratory professionals participated in the selected health facilities, with a response rate of (100%). Standardized pre-validated slide panels and questionnaire were distributed to laboratory professionals by the principal investigator. The panel slides were comprised of 5 positives and 3 negative blood films. The laboratory professionals were requested to report the parasite density using semi-quantitative (+) and per micro-liter methods. Their performances of slide readings were compared with the experts' readings. Agreement in detecting malaria parasites between laboratory professionals and expert was estimated using the kappa score. RESULTS The overall sensitivity and specificity of the laboratory professionals in detecting malaria parasites were 83% and 97%, respectively. Similarly, positive predictive values of 98.1% and negative predictive values of 77.7% were reported. The percent agreement between laboratory professionals and expert microscopist in the detection of malaria parasites was 88.5% with a Kappa index of 0.78. Percent agreement in species identification and reporting of Pf/Pv mixed infections were 27.2% and 22.4%, respectively. About 62.2% of the laboratory professionals reported parasite density using semi-quantitative method. While none of them reported per micro-liter method. CONCLUSIONS The current study showed that laboratory professionals had good performance in parasite detection. However, poor performance was seen in both species identification and reporting of Pf/Pv mixed infections.
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Affiliation(s)
| | - Mulat Yimer Melaku
- Department of Medical Laboratory Sciences, School of Health Sciences, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia
| | - Tadesse Hailu Jemeber
- Department of Medical Laboratory Sciences, School of Health Sciences, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia
| | - Megbaru Alemu Abate
- Department of Medical Laboratory Sciences, School of Health Sciences, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia
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Poostchi M, Silamut K, Maude RJ, Jaeger S, Thoma G. Image analysis and machine learning for detecting malaria. Transl Res 2018; 194:36-55. [PMID: 29360430 PMCID: PMC5840030 DOI: 10.1016/j.trsl.2017.12.004] [Citation(s) in RCA: 122] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 12/07/2017] [Accepted: 12/19/2017] [Indexed: 12/11/2022]
Abstract
Malaria remains a major burden on global health, with roughly 200 million cases worldwide and more than 400,000 deaths per year. Besides biomedical research and political efforts, modern information technology is playing a key role in many attempts at fighting the disease. One of the barriers toward a successful mortality reduction has been inadequate malaria diagnosis in particular. To improve diagnosis, image analysis software and machine learning methods have been used to quantify parasitemia in microscopic blood slides. This article gives an overview of these techniques and discusses the current developments in image analysis and machine learning for microscopic malaria diagnosis. We organize the different approaches published in the literature according to the techniques used for imaging, image preprocessing, parasite detection and cell segmentation, feature computation, and automatic cell classification. Readers will find the different techniques listed in tables, with the relevant articles cited next to them, for both thin and thick blood smear images. We also discussed the latest developments in sections devoted to deep learning and smartphone technology for future malaria diagnosis.
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Affiliation(s)
- Mahdieh Poostchi
- U.S. National Library of Medicine, National Institutes of Health, Bethesda, Maryland
| | - Kamolrat Silamut
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
| | - Richard J Maude
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; Harvard TH Chan School of Public Health, Harvard University, Boston, Massachusetts
| | - Stefan Jaeger
- U.S. National Library of Medicine, National Institutes of Health, Bethesda, Maryland.
| | - George Thoma
- U.S. National Library of Medicine, National Institutes of Health, Bethesda, Maryland
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Yang X, Chen Z, Miao J, Cui L, Guan W. High-throughput and label-free parasitemia quantification and stage differentiation for malaria-infected red blood cells. Biosens Bioelectron 2017; 98:408-414. [PMID: 28711027 PMCID: PMC5558593 DOI: 10.1016/j.bios.2017.07.019] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 07/04/2017] [Accepted: 07/08/2017] [Indexed: 12/16/2022]
Abstract
This work reports a high throughput and label-free microfluidic cell deformability sensor for quantitative parasitemia measurement and stage determination for Plasmodium falciparum-infected red blood cells (Pf-iRBCs). The sensor relies on differentiating the RBC deformability (a mechanical biomarker) that is highly correlated with the infection status. The cell deformability is measured by evaluating the transit time when each individual RBC squeezes through a microscale constriction (cross-section ~5µm×5µm). More than 30,000 RBCs can be analyzed for parasitemia quantification in under 1min with a throughput ~500 cells/s. Moreover, the device can also differentiate various malaria stages (ring, trophozoite, and schizont stage) due to their varied deformability. Using Pf-iRBCs at 0.1% parasitemia as a testing sample, the microfluidic deformability sensor achieved an excellent sensitivity (94.29%), specificity (86.67%) and accuracy (92.00%) in a blind test, comparable to the gold standard of the blood smear microscopy. As a supplement technology to the microscopy and flow cytometry, the microfluidic deformability sensor would possibly allow for label-free, rapid and cost-effective parasitemia quantification and stage determination for malaria in remote regions.
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Affiliation(s)
- Xiaonan Yang
- Department of Electrical Engineering, Pennsylvania State University, University Park 16802, USA; School of Information Engineering, Zhengzhou University, Zhengzhou 450000, China
| | - Zhuofa Chen
- Department of Electrical Engineering, Pennsylvania State University, University Park 16802, USA
| | - Jun Miao
- Department of Entomology, Pennsylvania State University, University Park 16802, USA
| | - Liwang Cui
- Department of Entomology, Pennsylvania State University, University Park 16802, USA
| | - Weihua Guan
- Department of Electrical Engineering, Pennsylvania State University, University Park 16802, USA; Department of Biomedical Engineering, Pennsylvania State University, University Park 16802, USA.
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Aiyenigba B, Ojo A, Aisiri A, Uzim J, Adeusi O, Mwenesi H. Immediate assessment of performance of medical laboratory scientists following a 10-day malaria microscopy training programme in Nigeria. Glob Health Res Policy 2017; 2:32. [PMID: 29202100 PMCID: PMC5683359 DOI: 10.1186/s41256-017-0051-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 09/28/2017] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Rapid and precise diagnosis of malaria is an essential element in effective case management and control of malaria. Malaria microscopy is used as the gold standard for malaria diagnosis, however results remain poor as positivity rate in Nigeria is consistently over 90%. The United States President's Malaria Initiative (PMI) through the Malaria Action Program for States (MAPS) supported selected states in Nigeria to build capacity for malaria microscopy. This study demonstrates the effectiveness of in-service training on malaria microscopy amongst medical laboratory scientists. METHOD The training was based on the World Health Organization (WHO) basic microscopy training manual. The 10-day training utilized a series of didactic lectures and examination of teaching slides using a CX 21 Olympus binocular microscope. All 108 medical laboratory scientists trained from 2012 to 2015 across five states in Nigeria supported by PMI were included in the study. Evaluation of the training using a pre-and post-test method was based on written test questions; reading photographic slide images of malaria parasites; and prepared slides. RESULT There was a significant improvement in the mean written pre-and post-tests scores from 37.9% (95% CI 36.2-39.6%) to 70.7% (95% CI 68.4-73.1%) (p < 0.001). The mean counting post-test score improved significantly from 4.2% (95% CI 2.6-5.7%) to 27.9% (95% CI 25.3-30.5%) (p < 0.001). Mean post-test score for computer-based picture speciation test (63.0%) and picture detection test (89.2%) were significantly higher than the mean post-test score for slide reading speciation test (38.3%) and slide reading detection test (70.7%), p < 0.001 in both cases. CONCLUSION Parasite detection and speciation using enhanced visual imaging was significantly improved compared with using direct microscopy. Regular in-service training and provision of functional and high resolution microscopes are needed to ensure quality routine malaria microscopy.
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Pollak JJ, Houri-Yafin A, Salpeter SJ. Computer Vision Malaria Diagnostic Systems-Progress and Prospects. Front Public Health 2017; 5:219. [PMID: 28879175 PMCID: PMC5573428 DOI: 10.3389/fpubh.2017.00219] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 08/07/2017] [Indexed: 12/17/2022] Open
Abstract
Accurate malaria diagnosis is critical to prevent malaria fatalities, curb overuse of antimalarial drugs, and promote appropriate management of other causes of fever. While several diagnostic tests exist, the need for a rapid and highly accurate malaria assay remains. Microscopy and rapid diagnostic tests are the main diagnostic modalities available, yet they can demonstrate poor performance and accuracy. Automated microscopy platforms have the potential to significantly improve and standardize malaria diagnosis. Based on image recognition and machine learning algorithms, these systems maintain the benefits of light microscopy and provide improvements such as quicker scanning time, greater scanning area, and increased consistency brought by automation. While these applications have been in development for over a decade, recently several commercial platforms have emerged. In this review, we discuss the most advanced computer vision malaria diagnostic technologies and investigate several of their features which are central to field use. Additionally, we discuss the technological and policy barriers to implementing these technologies in low-resource settings world-wide.
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Abebe A, Belayneh M, Asrat H, Kassa W, Gashu A, Desale A, Hailu G, Mekonnen T, Girmachew F, Mulugeta A, Abose E, Yenealem D, Tsadik AG, Kebede A, Ayana G, Desta K. Performance evaluation of malaria microscopists working at rechecking laboratories in Ethiopia. MALARIAWORLD JOURNAL 2017; 8:6. [PMID: 34532230 PMCID: PMC8415073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
BACKGROUND Microscopic diagnosis of Giemsa-stained thick and thin blood films has remained the standard laboratory method for diagnosing malaria. High quality performance of microscopists that examine blood slides in health facilities remains critically important. MATERIALS AND METHODS A cross-sectional study was conducted to assess the performance of 107 malaria microscopists working at 23 malaria rechecking laboratories in Ethiopia. A set of 12 blood film slides was distributed to each microscopist. Data was collected and exported to SPSS version 20 for analysis. Chi-square, sensitivity, specificity, percent agreement, and kappa scores were calculated to assess performance in detecting and identification of Plasmodium species. RESULTS The mean age of the participants was 30 ± 5 yrs and most of them (54; 50.5%) were working at regional reference laboratories. Overall, the sensitivity of participants in detecting and identifying malaria parasite species was 96.8% and 56.7%, respectively. The overall agreement on detection and identification of malaria species was 96.8% (Kappa = 0.9) and 64.8% (Kappa = 0.33), respectively. The least accurately identified malaria parasite species was P. malariae (3/107; 2.8%) followed by P. ovale (35/107; 32.7%). Participants working at hospital laboratories had the highest percentage (72.3 %, Kappa=0.51) of accurate species identification. Study participants that had participated in malaria microscopy and quality assurance trainings were significantly better at quantifying parasite densities (P<0.001). CONCLUSION The accuracy of parasite identification and quantification differed strongly between participants and expert microscopists. Therefore, regular competency assessment and training for malaria microscopists should be mandatory to assure proper diagnosis and management of malaria in Ethiopia.
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Affiliation(s)
- Abnet Abebe
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia,*
| | - Meseret Belayneh
- Department of Medical Laboratory Sciences, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Habtamu Asrat
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | | | | | - Adino Desale
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Getnet Hailu
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | | | | | | | - Ebise Abose
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | | | - Abeba G Tsadik
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Adisu Kebede
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Gonfa Ayana
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Kassu Desta
- Department of Medical Laboratory Sciences, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
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Yitbarek T, Nega D, Tasew G, Taye B, Desta K. Performance Evaluation of Malaria Microscopists at Defense Health Facilities in Addis Ababa and Its Surrounding Areas, Ethiopia. PLoS One 2016; 11:e0166170. [PMID: 27893838 PMCID: PMC5125591 DOI: 10.1371/journal.pone.0166170] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Accepted: 10/23/2016] [Indexed: 11/19/2022] Open
Abstract
Background Blood film microscopy is the gold standard approach for malaria diagnosis, and preferred method for routine patient diagnosis in health facilities. However, the inability of laboratory professionals to correctly detect and identify malaria parasites microscopically leads to an inappropriate administration of anti-malarial drugs to the patients and incorrect findings in research areas. This study was carried out to evaluate the performance of laboratory professionals in malaria diagnosis in health facilities under the Defense Health Main Department in Addis Ababa and its surroundings, Ethiopia. Method A cross sectional study was conducted from June to July 2015. Totally, 60 laboratory professionals out of the selected 16 health facilities were included in the study. Data were collected by distributing standardized pre-validated malaria slide-panels and self-administered questionnaires among professionals, onsite in each study facility. Sensitivity, specificity, and strength of agreement (with kappa score) in performance among the study participants against WHO-certified expert malaria microscopists were calculated. Result Of the 60 study participants, 8.3% (5/60) correctly read all the distributed slides in terms of parasite detection, species identification and parasite counting; whereas, each of the remaining 55(91.7%) interpreted at least two slides incorrectly. The overall sensitivity and specificity of participants’ performance in detection of malaria parasites were 65.7% and 100%, respectively. Overall, fair agreement (71.4%; Kappa: 0.4) in detection of malaria parasite was observed between the study subjects and expert readers. The overall sensitivity and specificity of participants in species identification of malaria parasites were respectively 41.3% and 100%. Overall, slight agreement (51.1%; kappa: 0.04) in identification of malaria species was observed. Generally, agreement was lower in parasite detection and species identification at low parasite density and mixed infection cases. Conclusion The general agreement between the study participants and expert microscopists in malaria parasite detection and species identification was very low, particularly in the cases of low-parasite density and mixed infections. Therefore, regular external quality assessments and further refreshment trainings are crucial to enhance the skill of professionals in malaria microscopy; particularly for those in non-malarious areas where exposure to malaria diagnosis is low.
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Affiliation(s)
- Tigist Yitbarek
- Emanuel Mental Specialized Hospital, Medical Laboratory Service, Addis Ababa, Ethiopia
- Department of Medical Laboratory Sciences, Collage of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
- * E-mail:
| | - Desalegn Nega
- Malaria, Other Parasite and Vector Borne Parasitic Diseases Research Team; Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Geremew Tasew
- Malaria, Other Parasite and Vector Borne Parasitic Diseases Research Team; Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Bineyam Taye
- Colgate University, Department of Biology, Hamilton, New York, United States of America
| | - Kassu Desta
- Department of Medical Laboratory Sciences, Collage of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
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Srivastava B, Anvikar AR, Ghosh SK, Mishra N, Kumar N, Houri-Yafin A, Pollak JJ, Salpeter SJ, Valecha N. Computer-vision-based technology for fast, accurate and cost effective diagnosis of malaria. Malar J 2015; 14:526. [PMID: 26714633 PMCID: PMC4696165 DOI: 10.1186/s12936-015-1060-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 12/17/2015] [Indexed: 01/01/2023] Open
Abstract
Background Microscopy
has long been considered to be the gold standard for diagnosis of malaria despite the introduction of newer assays. However, it has many challenges like requirement of trained microscopists and logistic issues. A vision based device that can diagnose malaria, provide speciation and estimate parasitaemia was evaluated. Methods The device was evaluated using samples from 431 consented patients, 361 of which were initially screened by RDT and microscopy and later analysed by PCR. It was a prospective, non-randomized, blinded trial. Quantification of parasitaemia was performed by two experienced technicians. Samples were subjected to diagnosis by Sight Dx digital imaging scanning. Results The sensitivity and specificity of the SightDx P1 device for analysed samples were found to be 97.05 and 96.33 %, respectively, when compared to PCR. When compared to microscopy, sensitivity and specificity were found to be 94.4 and 95.6 %, respectively. The device was able to speciate 73.3 % of the PCR Plasmodium falciparum positive samples and 91.4 % of PCR Plasmodium vivax positive samples. Conclusion The ability of the device to detect parasitaemia as compared with microscopy, was within 50 % in 71.3 % of cases and demonstrated a correlation coefficient of 0.89.
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Affiliation(s)
- Bina Srivastava
- National Institute of Malaria Research, Sector 8 Dwarka, New Delhi, 110 077, India.
| | - Anupkumar R Anvikar
- National Institute of Malaria Research, Sector 8 Dwarka, New Delhi, 110 077, India.
| | - Susanta K Ghosh
- National Institute of Malaria Research Field Unit, Bengaluru, India.
| | - Neelima Mishra
- National Institute of Malaria Research, Sector 8 Dwarka, New Delhi, 110 077, India.
| | - Navin Kumar
- National Institute of Malaria Research, Sector 8 Dwarka, New Delhi, 110 077, India.
| | - Arnon Houri-Yafin
- Sight Diagnostics, 1 Agudat Hasport Hapoel, Jerusalem Technology Park, Jerusalem, Israel.
| | - Joseph Joel Pollak
- Sight Diagnostics, 1 Agudat Hasport Hapoel, Jerusalem Technology Park, Jerusalem, Israel.
| | - Seth J Salpeter
- Sight Diagnostics, 1 Agudat Hasport Hapoel, Jerusalem Technology Park, Jerusalem, Israel.
| | - Neena Valecha
- National Institute of Malaria Research, Sector 8 Dwarka, New Delhi, 110 077, India.
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15
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Linder N, Turkki R, Walliander M, Mårtensson A, Diwan V, Rahtu E, Pietikäinen M, Lundin M, Lundin J. A malaria diagnostic tool based on computer vision screening and visualization of Plasmodium falciparum candidate areas in digitized blood smears. PLoS One 2014; 9:e104855. [PMID: 25144549 PMCID: PMC4140733 DOI: 10.1371/journal.pone.0104855] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 07/16/2014] [Indexed: 11/26/2022] Open
Abstract
Introduction Microscopy is the gold standard for diagnosis of malaria, however, manual evaluation of blood films is highly dependent on skilled personnel in a time-consuming, error-prone and repetitive process. In this study we propose a method using computer vision detection and visualization of only the diagnostically most relevant sample regions in digitized blood smears. Methods Giemsa-stained thin blood films with P. falciparum ring-stage trophozoites (n = 27) and uninfected controls (n = 20) were digitally scanned with an oil immersion objective (0.1 µm/pixel) to capture approximately 50,000 erythrocytes per sample. Parasite candidate regions were identified based on color and object size, followed by extraction of image features (local binary patterns, local contrast and Scale-invariant feature transform descriptors) used as input to a support vector machine classifier. The classifier was trained on digital slides from ten patients and validated on six samples. Results The diagnostic accuracy was tested on 31 samples (19 infected and 12 controls). From each digitized area of a blood smear, a panel with the 128 most probable parasite candidate regions was generated. Two expert microscopists were asked to visually inspect the panel on a tablet computer and to judge whether the patient was infected with P. falciparum. The method achieved a diagnostic sensitivity and specificity of 95% and 100% as well as 90% and 100% for the two readers respectively using the diagnostic tool. Parasitemia was separately calculated by the automated system and the correlation coefficient between manual and automated parasitemia counts was 0.97. Conclusion We developed a decision support system for detecting malaria parasites using a computer vision algorithm combined with visualization of sample areas with the highest probability of malaria infection. The system provides a novel method for blood smear screening with a significantly reduced need for visual examination and has a potential to increase the throughput in malaria diagnostics.
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Affiliation(s)
- Nina Linder
- Institute for Molecular Medicine Finland, University of Helsinki, Helsinki, Finland
- * E-mail:
| | - Riku Turkki
- Institute for Molecular Medicine Finland, University of Helsinki, Helsinki, Finland
| | - Margarita Walliander
- Institute for Molecular Medicine Finland, University of Helsinki, Helsinki, Finland
| | - Andreas Mårtensson
- Department of Public Health Sciences, Karolinska Institute, Stockholm, Sweden
| | - Vinod Diwan
- Department of Public Health Sciences, Karolinska Institute, Stockholm, Sweden
| | - Esa Rahtu
- Department of Computer Science and Engineering, University of Oulu, Oulu, Finland
| | - Matti Pietikäinen
- Department of Computer Science and Engineering, University of Oulu, Oulu, Finland
| | - Mikael Lundin
- Institute for Molecular Medicine Finland, University of Helsinki, Helsinki, Finland
| | - Johan Lundin
- Institute for Molecular Medicine Finland, University of Helsinki, Helsinki, Finland
- Department of Public Health Sciences, Karolinska Institute, Stockholm, Sweden
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16
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Horning MP, Delahunt CB, Singh SR, Garing SH, Nichols KP. A paper microfluidic cartridge for automated staining of malaria parasites with an optically transparent microscopy window. LAB ON A CHIP 2014; 14:2040-2046. [PMID: 24781199 DOI: 10.1039/c4lc00293h] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A paper microfluidic cartridge for the automated staining of malaria parasites (Plasmodium) with acridine orange prior to microscopy is presented. The cartridge enables simultaneous, sub-minute generation of both thin and thick smears of acridine orange stained parasites. Parasites are stained in a cellulose matrix, after which the parasites are ejected via capillary forces into an optically transparent chamber. The unique slanted design of the chamber ensures that a high percentage of the stained blood will be of the required thickness for a thin smear, without resorting to spacers or other methods that can increase production cost or require tight quality controls. A hydrophobic snorkel facilitates the removal of air bubbles during filling. The cartridge contains both a thin smear region, where a single layer of cells is presented unobstructed, for ease of species identification, and a thick smear region, containing multiple cell layers, for enhanced limit of detection.
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Affiliation(s)
- Matthew P Horning
- Intellectual Ventures Laboratory, 1555 132nd Ave NE, Bellevue, WA 98005, USA.
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17
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Delahunt C, Horning MP, Wilson BK, Proctor JL, Hegg MC. Limitations of haemozoin-based diagnosis of Plasmodium falciparum using dark-field microscopy. Malar J 2014; 13:147. [PMID: 24739286 PMCID: PMC4021049 DOI: 10.1186/1475-2875-13-147] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2014] [Accepted: 04/12/2014] [Indexed: 11/13/2022] Open
Abstract
Background The haemozoin crystal continues to be investigated extensively for its potential as a biomarker for malaria diagnostics. In order for haemozoin to be a valuable biomarker, it must be present in detectable quantities in the peripheral blood and distinguishable from false positives. Here, dark-field microscopy coupled with sophisticated image processing algorithms is used to characterize the abundance of detectable haemozoin within infected erythrocytes from field samples in order to determine the window of detection in peripheral blood. Methods Thin smears from Plasmodium falciparum-infected and uninfected patients were imaged in both dark field (DF) unstained and bright field (BF) Giemsa-stained modes. The images were co-registered such that each parasite had thumbnails in both BF and DF modes, providing an accurate map between parasites and DF objects. This map was used to find the abundance of haemozoin as a function of parasite stage through careful parasite staging and correlation with DF objects. An automated image-processing and classification algorithm classified the bright spots in the DF images as either haemozoin or non-haemozoin objects. Results The algorithm distinguishes haemozoin from non-haemozoin objects in DF images with an object-level sensitivity of 95% and specificity of 97%. Ring stages older than about 6 hours begin to show detectable haemozoin, and rings between 10–16 hours reliably contain detectable haemozoin. However, DF microscopy coupled with the image-processing algorithm detect no haemozoin in rings younger than six hours. Discussion Although this method demonstrates the most sensitive detection of haemozoin in field samples reported to date, it does not detect haemozoin in ring-stage parasites younger than six hours. Thus, haemozoin is a poor biomarker for field samples primarily composed of young ring-stage parasites because the crystal is not present in detectable quantities by the methods described here. Based on these results, the implications for patient-level diagnosis and recommendations for future work are discussed.
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18
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Murphy SC, Shott JP, Parikh S, Etter P, Prescott WR, Stewart VA. Malaria diagnostics in clinical trials. Am J Trop Med Hyg 2013; 89:824-39. [PMID: 24062484 PMCID: PMC3820323 DOI: 10.4269/ajtmh.12-0675] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Accepted: 08/05/2013] [Indexed: 11/07/2022] Open
Abstract
Malaria diagnostics are widely used in epidemiologic studies to investigate natural history of disease and in drug and vaccine clinical trials to exclude participants or evaluate efficacy. The Malaria Laboratory Network (MLN), managed by the Office of HIV/AIDS Network Coordination, is an international working group with mutual interests in malaria disease and diagnosis and in human immunodeficiency virus/acquired immunodeficiency syndrome clinical trials. The MLN considered and studied the wide array of available malaria diagnostic tests for their suitability for screening trial participants and/or obtaining study endpoints for malaria clinical trials, including studies of HIV/malaria co-infection and other malaria natural history studies. The MLN provides recommendations on microscopy, rapid diagnostic tests, serologic tests, and molecular assays to guide selection of the most appropriate test(s) for specific research objectives. In addition, this report provides recommendations regarding quality management to ensure reproducibility across sites in clinical trials. Performance evaluation, quality control, and external quality assessment are critical processes that must be implemented in all clinical trials using malaria tests.
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Affiliation(s)
- Sean C. Murphy
- Department of Laboratory Medicine, University of Washington Medical Center, Seattle, Washington; Division of Intramural Research, National Institute of Allergy and Infectious Diseases,National Institutes of Health, Bethesda, Maryland; Yale University School of Public Health, New Haven, Connecticut; Office of HIV/AIDS Network Coordination, Fred Hutchinson Cancer Research Center, Seattle, Washington; Hydas World Health, Hershey, Pennsylvania; Uniformed Services University of the Health Sciences, Bethesda, Maryland
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19
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Serebrennikova YM, Patel J, Milhous WK, Garcia-Rubio LH, Huffman DE, Smith JM. Spectrophotometric detection of susceptibility to anti-malarial drugs. Malar J 2013; 12:305. [PMID: 23992478 PMCID: PMC3849014 DOI: 10.1186/1475-2875-12-305] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Accepted: 08/02/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND With malaria drug resistance increasing in prevalence and severity, new technologies are needed to aid and improve the accuracy and clinical relevance of laboratory or field testing for malaria drug resistance. This study presents a method based on simple and reagentless spectroscopic measurements coupled with comprehensive spectral interpretation analysis that provides valuable quantitative information on the morphological and compositional responses of Plasmodium falciparum and infected red blood cells (IRBCs) to anti-malarial treatment. METHODS The changes in the size, internal structure, nucleotide and haemozoin composition of the parasites as well as the morphology (size and shape) and haemoglobin composition of the IRBCs treated with dihydroartemisinin (DHA) and mefloquine (MFQ) were investigated using a spectral interpretation analysis. RESULTS DHA treatment reduced the sizes of the parasites and their structural organelles. The haemoglobin composition of the host IRBCs determined from spectroscopic analysis changed negligibly following DHA treatment. MFQ treated parasites grew to the same size as those from parallel non-treated cultures but lacked haemozoin. Lesser deformation of the cell shape and no haemoglobin depletion were detected for the IRBCs of MFQ treated cultures. CONCLUSIONS The spectroscopic analysis method proved to be sensitive for recognition of the effects of anti-malarial treatment on the structure and composition of the parasites and IRBCs. The method can have significant potential for research and clinical applications such as evaluating patient specimens for drug action, drug effects or for therapeutic monitoring.
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Affiliation(s)
- Yulia M Serebrennikova
- College of Public Health, University of South Florida, 13201 Bruce B, Downs Blvd,, Tampa, FL 33612, USA.
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20
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Luengo-Oroz MA, Arranz A, Frean J. Crowdsourcing malaria parasite quantification: an online game for analyzing images of infected thick blood smears. J Med Internet Res 2012. [PMID: 23196001 PMCID: PMC3510720 DOI: 10.2196/jmir.2338] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Background There are 600,000 new malaria cases daily worldwide. The gold standard for estimating the parasite burden and the corresponding severity of the disease consists in manually counting the number of parasites in blood smears through a microscope, a process that can take more than 20 minutes of an expert microscopist’s time. Objective This research tests the feasibility of a crowdsourced approach to malaria image analysis. In particular, we investigated whether anonymous volunteers with no prior experience would be able to count malaria parasites in digitized images of thick blood smears by playing a Web-based game. Methods The experimental system consisted of a Web-based game where online volunteers were tasked with detecting parasites in digitized blood sample images coupled with a decision algorithm that combined the analyses from several players to produce an improved collective detection outcome. Data were collected through the MalariaSpot website. Random images of thick blood films containing Plasmodium falciparum at medium to low parasitemias, acquired by conventional optical microscopy, were presented to players. In the game, players had to find and tag as many parasites as possible in 1 minute. In the event that players found all the parasites present in the image, they were presented with a new image. In order to combine the choices of different players into a single crowd decision, we implemented an image processing pipeline and a quorum algorithm that judged a parasite tagged when a group of players agreed on its position. Results Over 1 month, anonymous players from 95 countries played more than 12,000 games and generated a database of more than 270,000 clicks on the test images. Results revealed that combining 22 games from nonexpert players achieved a parasite counting accuracy higher than 99%. This performance could be obtained also by combining 13 games from players trained for 1 minute. Exhaustive computations measured the parasite counting accuracy for all players as a function of the number of games considered and the experience of the players. In addition, we propose a mathematical equation that accurately models the collective parasite counting performance. Conclusions This research validates the online gaming approach for crowdsourced counting of malaria parasites in images of thick blood films. The findings support the conclusion that nonexperts are able to rapidly learn how to identify the typical features of malaria parasites in digitized thick blood samples and that combining the analyses of several users provides similar parasite counting accuracy rates as those of expert microscopists. This experiment illustrates the potential of the crowdsourced gaming approach for performing routine malaria parasite quantification, and more generally for solving biomedical image analysis problems, with future potential for telediagnosis related to global health challenges.
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Affiliation(s)
- Miguel Angel Luengo-Oroz
- Biomedical Image Technologies group, DIE, ETSI Telecomunicación, Universidad Politécnica de Madrid, CEI Moncloa UPM-UCM, Madrid, Spain.
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Mavandadi S, Feng S, Yu F, Dimitrov S, Nielsen-Saines K, Prescott WR, Ozcan A. A mathematical framework for combining decisions of multiple experts toward accurate and remote diagnosis of malaria using tele-microscopy. PLoS One 2012; 7:e46192. [PMID: 23071544 PMCID: PMC3469564 DOI: 10.1371/journal.pone.0046192] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 08/28/2012] [Indexed: 11/19/2022] Open
Abstract
We propose a methodology for digitally fusing diagnostic decisions made by multiple medical experts in order to improve accuracy of diagnosis. Toward this goal, we report an experimental study involving nine experts, where each one was given more than 8,000 digital microscopic images of individual human red blood cells and asked to identify malaria infected cells. The results of this experiment reveal that even highly trained medical experts are not always self-consistent in their diagnostic decisions and that there exists a fair level of disagreement among experts, even for binary decisions (i.e., infected vs. uninfected). To tackle this general medical diagnosis problem, we propose a probabilistic algorithm to fuse the decisions made by trained medical experts to robustly achieve higher levels of accuracy when compared to individual experts making such decisions. By modelling the decisions of experts as a three component mixture model and solving for the underlying parameters using the Expectation Maximisation algorithm, we demonstrate the efficacy of our approach which significantly improves the overall diagnostic accuracy of malaria infected cells. Additionally, we present a mathematical framework for performing ‘slide-level’ diagnosis by using individual ‘cell-level’ diagnosis data, shedding more light on the statistical rules that should govern the routine practice in examination of e.g., thin blood smear samples. This framework could be generalized for various other tele-pathology needs, and can be used by trained experts within an efficient tele-medicine platform.
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Affiliation(s)
- Sam Mavandadi
- Electrical Engineering Department, University of California Los Angeles, Los Angeles, California, United States of America
- Bioengineering Department, University of California Los Angeles, Los Angeles, California, United States of America
| | - Steve Feng
- Electrical Engineering Department, University of California Los Angeles, Los Angeles, California, United States of America
- Bioengineering Department, University of California Los Angeles, Los Angeles, California, United States of America
| | - Frank Yu
- Electrical Engineering Department, University of California Los Angeles, Los Angeles, California, United States of America
- Bioengineering Department, University of California Los Angeles, Los Angeles, California, United States of America
| | - Stoyan Dimitrov
- Electrical Engineering Department, University of California Los Angeles, Los Angeles, California, United States of America
- Bioengineering Department, University of California Los Angeles, Los Angeles, California, United States of America
| | - Karin Nielsen-Saines
- Division of Infectious Diseases, Department of Pediatrics, School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | | | - Aydogan Ozcan
- Electrical Engineering Department, University of California Los Angeles, Los Angeles, California, United States of America
- Bioengineering Department, University of California Los Angeles, Los Angeles, California, United States of America
- California NanoSystems Institute, University of California Los Angeles, Los Angeles, California, United States of America
- Department of Surgery, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- * E-mail:
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