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Choi JW, Choi MJ, Kim YJ, Kim SY. Cloning, Expression, Purification, and Characterization of Lactate Dehydrogenase from Plasmodium knowlesi: A Zoonotic Malaria Parasite. Int J Mol Sci 2024; 25:5615. [PMID: 38891805 PMCID: PMC11171812 DOI: 10.3390/ijms25115615] [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: 03/27/2024] [Revised: 05/06/2024] [Accepted: 05/09/2024] [Indexed: 06/21/2024] Open
Abstract
Plasmodium knowlesi is the only Plasmodium that causes zoonotic disease among the Plasmodium that cause infection in humans. It is fatal due to its short asexual growth cycle within 24 h. Lactate dehydrogenase (LDH), an enzyme that catalyzes the final step of glycolysis, is a biomarker for diagnosing infection by Plasmodium spp. parasite. Therefore, this study aimed to efficiently produce the soluble form of P. knowlesi LDH (PkLDH) using a bacterial expression system for studying malaria caused by P. knowlesi. Recombinant pET-21a(+)-PkLDH plasmid was constructed by inserting the PkLDH gene into a pET-21a(+) expression vector. Subsequently, the recombinant plasmid was inserted into the protein-expressing Escherichia coli Rosetta(DE3) strain, and the optimal conditions for overexpression of the PkLDH protein were established using this strain. We obtained a yield of 52.0 mg/L PkLDH from the Rosetta(DE3) strain and confirmed an activity of 483.9 U/mg through experiments. This methodology for high-efficiency PkLDH production can be utilized for the development of diagnostic methods and drug candidates for distinguishing malaria caused by P. knowlesi.
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Affiliation(s)
- Jae-Won Choi
- Department of Biomedical Science, Cheongju University, Cheongju 28160, Republic of Korea
- Department of Biopharmaceutical Sciences, Cheongju University, Cheongju 28160, Republic of Korea
| | - Min-Ji Choi
- Department of Biomedical Science, Cheongju University, Cheongju 28160, Republic of Korea
| | - Yeon-Jun Kim
- Department of Biomedical Science, Cheongju University, Cheongju 28160, Republic of Korea
| | - So Yeon Kim
- Department of Dental Hygiene, Cheongju University, Cheongju 28503, Republic of Korea
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2
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Kayiba NK, Nitahara Y, Tshibangu-Kabamba E, Mbuyi DK, Kabongo-Tshibaka A, Kalala NT, Tshiebue BM, Candray-Medina KS, Kaku N, Nakagama Y, Speybroeck N, Mumba DN, Disashi GT, Kaneko A, Kido Y. Malaria infection among adults residing in a highly endemic region from the Democratic Republic of the Congo. Malar J 2024; 23:82. [PMID: 38500094 PMCID: PMC10946143 DOI: 10.1186/s12936-024-04881-7] [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: 03/17/2023] [Accepted: 02/15/2024] [Indexed: 03/20/2024] Open
Abstract
BACKGROUND Adults infected with Plasmodium spp. in endemic areas need to be re-evaluated in light of global malaria elimination goals. They potentially undermine malaria interventions but remain an overlooked aspect of public health strategies. METHODS This study aimed to estimate the prevalence of Plasmodium spp. infections, to identify underlying parasite species, and to assess predicting factors among adults residing in an endemic area from the Democratic Republic of Congo (DRC). A community-based cross-sectional survey in subjects aged 18 years and above was therefore carried out. Study participants were interviewed using a standard questionnaire and tested for Plasmodium spp. using a rapid diagnostic test and a nested polymerase chain reaction assay. Logistic regression models were fitted to assess the effect of potential predictive factors for infections with different Plasmodium spp. RESULTS Overall, 420 adults with an estimated prevalence of Plasmodium spp. infections of 60.2% [95% CI 55.5; 64.8] were included. Non-falciparum species infected 26.2% [95% CI 22.2; 30.5] of the study population. Among infected participants, three parasite species were identified, including Plasmodium falciparum (88.5%), Plasmodium malariae (39.9%), and Plasmodium ovale (7.5%) but no Plasmodium vivax. Mixed species accounted for 42.3% of infections while single-species infections predominated with P. falciparum (56.5%) among infected participants. All infected participants were asymptomatic at the time of the survey. Adults belonging to the "most economically disadvantaged" households had increased risks of infections with any Plasmodium spp. (adjusted odds ratio, aOR = 2.87 [95% CI 1.66, 20.07]; p < 0.001), compared to those from the "less economically disadvantaged" households. Conversely, each 1 year increase in age reduced the risk of infections with any Plasmodium spp. (aOR = 0.99 [95% CI 0.97, 0.99]; p = 0.048). Specifically for non-falciparum spp., males had increased risks of infection than females (aOR = 1.83 [95% CI 1.13, 2.96]; p = 0.014). CONCLUSION Adults infected with malaria constitute a potentially important latent reservoir for the transmission of the disease in the study setting. They should specifically be taken into account in public health measures and translational research.
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Affiliation(s)
- Nadine Kalenda Kayiba
- Research Center for Infectious Disease Sciences, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan
- Departments of Virology and Parasitology, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan
- Department of Public Health, Faculty of Medicine - Pharmacy and Public Health, University of Mbujimayi, Mbuji Mayi, Democratic Republic of Congo
- Research Institute of Health and Society, Université Catholique de Louvain, Brussels, Belgium
| | - Yuko Nitahara
- Research Center for Infectious Disease Sciences, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan
- Departments of Virology and Parasitology, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan
| | - Evariste Tshibangu-Kabamba
- Research Center for Infectious Disease Sciences, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan
- Departments of Virology and Parasitology, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan
- Department of Internal Medicine, Faculty of Medicine - Pharmacy and Public Health, University of Mbujimayi, Mbuji Mayi, Democratic Republic of Congo
| | - Denis Kalambayi Mbuyi
- Department of Internal Medicine, Faculty of Medicine - Pharmacy and Public Health, University of Mbujimayi, Mbuji Mayi, Democratic Republic of Congo
| | - Augustin Kabongo-Tshibaka
- Department of Internal Medicine, Faculty of Medicine - Pharmacy and Public Health, University of Mbujimayi, Mbuji Mayi, Democratic Republic of Congo
- Department of Molecular Infection Dynamics, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
| | - Nestor Tshituka Kalala
- Research Center for Infectious Disease Sciences, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan
- Departments of Virology and Parasitology, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan
- Department of Public Health, Faculty of Medicine - Pharmacy and Public Health, University of Mbujimayi, Mbuji Mayi, Democratic Republic of Congo
| | - Barthélemy Mukenga Tshiebue
- Department of Internal Medicine, Faculty of Medicine - Pharmacy and Public Health, University of Mbujimayi, Mbuji Mayi, Democratic Republic of Congo
| | - Katherine-Sofia Candray-Medina
- Research Center for Infectious Disease Sciences, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan
- Departments of Virology and Parasitology, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan
| | - Natsuko Kaku
- Research Center for Infectious Disease Sciences, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan
- Departments of Virology and Parasitology, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan
| | - Yu Nakagama
- Research Center for Infectious Disease Sciences, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan
- Departments of Virology and Parasitology, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan
| | - Niko Speybroeck
- Research Institute of Health and Society, Université Catholique de Louvain, Brussels, Belgium
| | - Dieudonné Ngoyi Mumba
- Department of Parasitology, Institut National de Recherche Biomédicale, Kinshasa, Democratic Republic of Congo
| | - Ghislain Tumba Disashi
- Department of Internal Medicine, Faculty of Medicine - Pharmacy and Public Health, University of Mbujimayi, Mbuji Mayi, Democratic Republic of Congo
| | - Akira Kaneko
- Research Center for Infectious Disease Sciences, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan
- Departments of Virology and Parasitology, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Yasutoshi Kido
- Research Center for Infectious Disease Sciences, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan.
- Departments of Virology and Parasitology, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan.
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3
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Lupaka M, Degefa T, Eba K, Zeynudin A, Yewhalaw D. Diagnostic performance of ultrasensitive rapid diagnostic test for the detection of Plasmodium falciparum infections in asymptomatic individuals in Kisangani, Northeast Democratic Republic of Congo. Malar J 2023; 22:354. [PMID: 37981691 PMCID: PMC10658930 DOI: 10.1186/s12936-023-04790-1] [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: 07/09/2023] [Accepted: 11/13/2023] [Indexed: 11/21/2023] Open
Abstract
BACKGROUND Ultrasensitive rapid diagnostic test (usRDT) was recently developed to improve the detection of low-density Plasmodium falciparum infections. However, its diagnostic performance has not been evaluated in the Democratic Republic of Congo (DRC). This study aims to determine the performance of the usRDT in malaria diagnosis in asymptomatic individuals under field condition in Kisangani, Northeast of DRC. METHODS A community-based cross-sectional study was carried out from June to August 2022 on 312 asymptomatic individuals residing in the city of Kisangani. Capillary blood samples were collected by finger prick for microscopic examination of thick and thin blood film, RDTs, and nested polymerase chain reaction (PCR). Alere™ Malaria Ag P.f usRDT and conventional RDT (cRDT/SD Bioline Malaria Ag P.f) kits were used for the detection of Plasmodium histidine rich protein 2 (HRP2) antigen as a proxy for the presence of P. falciparum. The diagnostic performance of the usRDT was compared with cRDT, microscopy and PCR. RESULTS The prevalence of asymptomatic P. falciparum malaria was 40.4%, 42.0%, 47.1% and 54.2% by cRDT, microscopy, usRDT and PCR, respectively. By using PCR as a reference, usRDT had sensitivity and specificity of 87.0% (95% CI 81.4-91.7) and 100.0% (95% CI 97.5-100.0), respectively, whereas the cRDT had sensitivity and specificity of 74.6% (95% CI 67.3-80.9) and 100% (95% CI 97.1-100.0), respectively. By using microscopy as a reference, usRDT had sensitivity and specificity of 96.9% (95% CI 92.4-99.2) and 89.0% (95% CI 83.5-93.1), respectively, while the cRDT had sensitivity and specificity of 96.2% (95% CI 92.3-98.7) and 100% (95% CI 97.9-100.0), respectively. CONCLUSION The usRDT showed better diagnostic performance with higher sensitivity than the cRDT which is currently in use as point-of-care test. Further research is necessary to assess the access and cost-effectiveness of the usRDTs to use for malaria surveillance.
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Affiliation(s)
- Mbumba Lupaka
- Faculty of Medicine and Pharmacy, University of Kisangani, Kisangani, Democratic Republic of the Congo
- School of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
| | - Teshome Degefa
- School of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia.
| | - Kasahun Eba
- Department of Environmental Health Sciences and Technology, Institute of Health, Jimma University, Jimma, Ethiopia
| | - Ahmed Zeynudin
- School of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
| | - Delenasaw Yewhalaw
- School of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
- Tropical and Infectious Diseases Research Center (TIDRC), Jimma University, Jimma, Ethiopia
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4
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Strules J, Dawant T, Riese K, Gerhold R, Brown J, Olfenbuttel C, DePerno CS, Hunt BJ, von Dohlen AR. USE OF A POINT OF CARE TEST TO DETERMINE THE PREVALENCE OF ANTIBODIES TO TOXOPLASMA GONDII IN BLACK BEARS FROM NORTH CAROLINA AND PENNSYLVANIA. J Parasitol 2023; 109:221-224. [PMID: 37327396 DOI: 10.1645/22-72] [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] [Indexed: 06/18/2023] Open
Abstract
Toxoplasma gondii is an important protozoan parasite of humans and animals throughout the world. Black bears are among the animals with the highest seroprevalence of T. gondii in the United States. A rapid point of care (POC) test is commercially available to detect antibodies to T. gondii in humans. We evaluated the utility of the POC test to detect anti-T. gondii antibodies in 100 wild black bears from North Carolina (n = 50) and Pennsylvania (n = 50). In a blind study, sera were tested by the POC test, and results were compared to the modified agglutination test (MAT). Overall, anti-T. gondii antibodies were detected in 76% (76/100) black bears by both MAT and POC tests. One false positive and one false negative result in the POC test were obtained in bears from Pennsylvania. The sensitivity and specificity of the POC test were both 99% when compared to the MAT. Results from our study indicate the POC test could be a useful screening tool for serological surveillance of T. gondii in black bears.
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Affiliation(s)
- Jennifer Strules
- Department of Forestry and Environmental Resources, Fisheries, Wildlife, and Conservation Biology, North Carolina State University, Raleigh, North Carolina 27606
| | - Tania Dawant
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, Tennessee 37996
| | - Katie Riese
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, Tennessee 37996
| | - Richard Gerhold
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, Tennessee 37996
| | - Justin Brown
- Department of Veterinary and Biomedical Sciences, Pennsylvania State University, University Park, Pennsylvania 16802
| | | | - Christopher S DePerno
- Department of Forestry and Environmental Resources, Fisheries, Wildlife, and Conservation Biology, North Carolina State University, Raleigh, North Carolina 27606
| | - Brian J Hunt
- Department of Computer Sciences, Engineering and Mathematics, College of Science, Technology, Engineering and Mathematics, Johnson C. Smith University, Charlotte, North Carolina 28216
| | - Alexa Rosypal von Dohlen
- Department of Natural and Behavioral Sciences, College of Science, Technology, Engineering and Mathematics, Johnson C. Smith University, Charlotte, North Carolina 28216
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Perez-Ugarte A, Rubio Maturana C, Silgado A, Zarzuela Serrat F, Goterris L, Paredes-Carmona F, Sulleiro E. Unexpected false-negative result in a traveller's malaria diagnosis. J Travel Med 2023; 30:6775350. [PMID: 36300508 DOI: 10.1093/jtm/taac124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 10/19/2022] [Accepted: 10/21/2022] [Indexed: 11/13/2022]
Abstract
A 4-year-old traveller returned from Senegal with symptoms compatible with malaria. Plasmodium falciparum HRP-2 antigen detection was negative, whereas panmalarial aldolase was positive. Microscopy confirmed the presence of P. falciparum trophozoites with parasitaemia of 16%. Discarding other causes of false-negative antigen detection, this is a rare case of prozone effect.
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Affiliation(s)
- Arantxa Perez-Ugarte
- Microbiology Department, Vall d'Hebron University Hospital, PROSICS Barcelona, Universitat Autònoma de Barcelona, Barcelona 08035, España
| | - Carles Rubio Maturana
- Microbiology Department, Vall d'Hebron Research Institute (VHIR), Universitat Autònoma de Barcelona, Barcelona 08035, España
| | - Aroa Silgado
- Microbiology Department, Vall d'Hebron University Hospital, PROSICS Barcelona, Universitat Autònoma de Barcelona, Barcelona 08035, España
- CIBERINFEC, ISCIII- CIBER Infectious Diseases, Instituto de Salud Carlos III, Madrid, Spain
| | - Francesc Zarzuela Serrat
- Microbiology Department, Vall d'Hebron University Hospital, PROSICS Barcelona, Universitat Autònoma de Barcelona, Barcelona 08035, España
| | - Lidia Goterris
- Microbiology Department, Vall d'Hebron University Hospital, PROSICS Barcelona, Universitat Autònoma de Barcelona, Barcelona 08035, España
| | | | - Elena Sulleiro
- Microbiology Department, Vall d'Hebron University Hospital, PROSICS Barcelona, Universitat Autònoma de Barcelona, Barcelona 08035, España
- CIBERINFEC, ISCIII- CIBER Infectious Diseases, Instituto de Salud Carlos III, Madrid, Spain
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6
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Maturana CR, de Oliveira AD, Nadal S, Bilalli B, Serrat FZ, Soley ME, Igual ES, Bosch M, Lluch AV, Abelló A, López-Codina D, Suñé TP, Clols ES, Joseph-Munné J. Advances and challenges in automated malaria diagnosis using digital microscopy imaging with artificial intelligence tools: A review. Front Microbiol 2022; 13:1006659. [PMID: 36458185 PMCID: PMC9705958 DOI: 10.3389/fmicb.2022.1006659] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 09/26/2022] [Indexed: 09/03/2023] Open
Abstract
Malaria is an infectious disease caused by parasites of the genus Plasmodium spp. It is transmitted to humans by the bite of an infected female Anopheles mosquito. It is the most common disease in resource-poor settings, with 241 million malaria cases reported in 2020 according to the World Health Organization. Optical microscopy examination of blood smears is the gold standard technique for malaria diagnosis; however, it is a time-consuming method and a well-trained microscopist is needed to perform the microbiological diagnosis. New techniques based on digital imaging analysis by deep learning and artificial intelligence methods are a challenging alternative tool for the diagnosis of infectious diseases. In particular, systems based on Convolutional Neural Networks for image detection of the malaria parasites emulate the microscopy visualization of an expert. Microscope automation provides a fast and low-cost diagnosis, requiring less supervision. Smartphones are a suitable option for microscopic diagnosis, allowing image capture and software identification of parasites. In addition, image analysis techniques could be a fast and optimal solution for the diagnosis of malaria, tuberculosis, or Neglected Tropical Diseases in endemic areas with low resources. The implementation of automated diagnosis by using smartphone applications and new digital imaging technologies in low-income areas is a challenge to achieve. Moreover, automating the movement of the microscope slide and image autofocusing of the samples by hardware implementation would systemize the procedure. These new diagnostic tools would join the global effort to fight against pandemic malaria and other infectious and poverty-related diseases.
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Affiliation(s)
- Carles Rubio Maturana
- Microbiology Department, Vall d’Hebron Research Institute, Vall d’Hebron Hospital Campus, Barcelona, Spain
- Universitat Autònoma de Barcelona (UAB), Barcelona, Spain
| | - Allisson Dantas de Oliveira
- Computational Biology and Complex Systems Group, Physics Department, Universitat Politècnica de Catalunya (UPC), Castelldefels, Spain
| | - Sergi Nadal
- Data Base Technologies and Information Group, Engineering Services and Information Systems Department, Universitat Politècnica de Catalunya (UPC), Barcelona, Spain
| | - Besim Bilalli
- Data Base Technologies and Information Group, Engineering Services and Information Systems Department, Universitat Politècnica de Catalunya (UPC), Barcelona, Spain
| | - Francesc Zarzuela Serrat
- Microbiology Department, Vall d’Hebron Research Institute, Vall d’Hebron Hospital Campus, Barcelona, Spain
| | - Mateu Espasa Soley
- Universitat Autònoma de Barcelona (UAB), Barcelona, Spain
- Clinical Laboratories, Microbiology Department, Hospital Universitari Parc Taulí, Sabadell, Spain
| | - Elena Sulleiro Igual
- Microbiology Department, Vall d’Hebron Research Institute, Vall d’Hebron Hospital Campus, Barcelona, Spain
- Universitat Autònoma de Barcelona (UAB), Barcelona, Spain
- CIBERINFEC, ISCIII- CIBER de Enfermedades Infecciosas, Instituto de Salud Carlos III, Madrid, Spain
| | | | | | - Alberto Abelló
- Data Base Technologies and Information Group, Engineering Services and Information Systems Department, Universitat Politècnica de Catalunya (UPC), Barcelona, Spain
| | - Daniel López-Codina
- Computational Biology and Complex Systems Group, Physics Department, Universitat Politècnica de Catalunya (UPC), Castelldefels, Spain
| | - Tomàs Pumarola Suñé
- Microbiology Department, Vall d’Hebron Research Institute, Vall d’Hebron Hospital Campus, Barcelona, Spain
- Universitat Autònoma de Barcelona (UAB), Barcelona, Spain
| | - Elisa Sayrol Clols
- Image Processing Group, Telecommunications and Signal Theory Group, Universitat Politècnica de Catalunya (UPC), Barcelona, Spain
| | - Joan Joseph-Munné
- Microbiology Department, Vall d’Hebron Research Institute, Vall d’Hebron Hospital Campus, Barcelona, Spain
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7
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Martiáñez-Vendrell X, Skjefte M, Sikka R, Gupta H. Factors Affecting the Performance of HRP2-Based Malaria Rapid Diagnostic Tests. Trop Med Infect Dis 2022; 7:tropicalmed7100265. [PMID: 36288006 PMCID: PMC9611031 DOI: 10.3390/tropicalmed7100265] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Revised: 09/14/2022] [Accepted: 09/21/2022] [Indexed: 11/16/2022] Open
Abstract
The recent COVID-19 pandemic has profoundly impacted global malaria elimination programs, resulting in a sharp increase in malaria morbidity and mortality. To reduce this impact, unmet needs in malaria diagnostics must be addressed while resuming malaria elimination activities. Rapid diagnostic tests (RDTs), the unsung hero in malaria diagnosis, work to eliminate the prevalence of Plasmodium falciparum malaria through their efficient, cost-effective, and user-friendly qualities in detecting the antigen HRP2 (histidine-rich protein 2), among other proteins. However, the testing mechanism and management of malaria with RDTs presents a variety of limitations. This paper discusses the numerous factors (including parasitic, host, and environmental) that limit the performance of RDTs. Additionally, the paper explores outside factors that can hinder RDT performance. By understanding these factors that affect the performance of HRP2-based RDTs in the field, researchers can work toward creating and implementing more effective and accurate HRP2-based diagnostic tools. Further research is required to understand the extent of these factors, as the rapidly changing interplay between parasite and host directly hinders the effectiveness of the tool.
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Affiliation(s)
- Xavier Martiáñez-Vendrell
- Molecular Virology Laboratory, Department of Medical Microbiology, LUMC Center for Infectious Diseases (LU-CID), Leiden University Medical Center, 2333 ZA Leiden, The Netherlands or
| | - Malia Skjefte
- Department of Global Health and Population, Harvard TH Chan School of Public Health, Boston, MA 02115, USA
| | - Ruhi Sikka
- Department of Biotechnology, Institute of Applied Sciences & Humanities, GLA University, Mathura 281406, UP, India
| | - Himanshu Gupta
- Department of Biotechnology, Institute of Applied Sciences & Humanities, GLA University, Mathura 281406, UP, India
- Correspondence: or
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8
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Tougan T, Hiyoshi F, Itagaki S, Horii T. Detection of histidine-rich protein 2- and/or 3-deleted Plasmodium falciparum using the automated hematology analyzer XN-31: A proof-of-concept study. Parasitol Int 2022; 91:102648. [PMID: 35988900 DOI: 10.1016/j.parint.2022.102648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 08/08/2022] [Accepted: 08/15/2022] [Indexed: 10/15/2022]
Abstract
Rapid diagnostic tests (RDTs) based on immunochromatographic detection of Plasmodium falciparum histidine-rich protein 2 (HRP2) have been frequently used for malaria diagnosis. The HRP2-based RDTs are highly sensitive and easy to use; however, their sensitivity may be low in detecting P. falciparum strains carrying deletion of the pfhrp2 and pfhrp3 genes encoding HRP2 and HRP3, respectively. The automated hematology analyzer XN-31, developed by Sysmex (Kobe, Japan) to aid in malaria diagnosis, has higher sensitivity than RDTs owing to a unique automated nucleic acid staining technology that has shown great potential in clinical settings. In this study, we compared the performance of the XN-31 analyzer and two RDTs to detect pfhrp2- and/or pfhrp3-deleted parasites cultured in vitro. The analyses showed that the analyzer was not only as sensitive to pfhrp2- and/or pfhrp3-deleted strains as it was to the wild-type strain but also had higher sensitivity than the RDTs. These results suggested that the XN-31 analyzer is useful for rapid and reliable detection of pfhrp2- and/or pfhrp3-deleted parasites in clinical settings.
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Affiliation(s)
- Takahiro Tougan
- Research Center for Infectious Disease Control, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Fumiya Hiyoshi
- Cell Technology Group, Reagent Engineering, Sysmex Corporation, 4-4-4 Takatsukadai Nishi-ku, Kobe 651-2271, Japan.
| | - Sawako Itagaki
- Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Toshihiro Horii
- Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
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9
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Vera-Arias CA, Holzschuh A, Oduma CO, Badu K, Abdul-Hakim M, Yukich J, Hetzel MW, Fakih BS, Ali A, Ferreira MU, Ladeia-Andrade S, Sáenz FE, Afrane Y, Zemene E, Yewhalaw D, Kazura JW, Yan G, Koepfli C. High-throughput Plasmodium falciparum hrp2 and hrp3 gene deletion typing by digital PCR to monitor malaria rapid diagnostic test efficacy. eLife 2022; 11:72083. [PMID: 35762586 PMCID: PMC9246365 DOI: 10.7554/elife.72083] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 06/05/2022] [Indexed: 01/11/2023] Open
Abstract
Most rapid diagnostic tests for Plasmodium falciparum malaria target the Histidine-Rich Proteins 2 and 3 (HRP2 and HRP3). Deletions of the hrp2 and hrp3 genes result in false-negative tests and are a threat for malaria control. A novel assay for molecular surveillance of hrp2/hrp3 deletions was developed based on droplet digital PCR (ddPCR). The assay quantifies hrp2, hrp3, and a control gene with very high accuracy. The theoretical limit of detection was 0.33 parasites/µl. The deletion was reliably detected in mixed infections with wild-type and hrp2-deleted parasites at a density of >100 parasites/reaction. For a side-by-side comparison with the conventional nested PCR (nPCR) assay, 248 samples were screened in triplicate by ddPCR and nPCR. No deletions were observed by ddPCR, while by nPCR hrp2 deletion was observed in 8% of samples. The ddPCR assay was applied to screen 830 samples from Kenya, Zanzibar/Tanzania, Ghana, Ethiopia, Brazil, and Ecuador. Pronounced differences in the prevalence of deletions were observed among sites, with more hrp3 than hrp2 deletions. In conclusion, the novel ddPCR assay minimizes the risk of false-negative results (i.e., hrp2 deletion observed when the sample is wild type), increases sensitivity, and greatly reduces the number of reactions that need to be run.
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Affiliation(s)
| | - Aurel Holzschuh
- University of Notre Dame, Notre Dame, United States.,Swiss Tropical and Public Health Institute, Allschwil, Switzerland
| | - Colins O Oduma
- Kenya Medical Research Institute-Centre for Global Health Research, Kisumu, Kenya.,Department of Biochemistry and Molecular Biology, Egerton University, Nakuru, Kenya
| | - Kingsley Badu
- Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | | | | | - Manuel W Hetzel
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland.,University of Basel, Basel, Switzerland
| | - Bakar S Fakih
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland.,University of Basel, Basel, Switzerland.,Ifakara Health Institute, Dar es Salaam, United Republic of Tanzania
| | - Abdullah Ali
- Zanzibar Malaria Elimination Programme, Zanzibar, Zanzibar, United Republic of Tanzania
| | | | | | - Fabián E Sáenz
- Centro de Investigación para la Salud en América Latina, Facultad de Ciencias Exactas y Naturales, Pontificia Universidad Católica del Ecuador, Quito, Ecuador
| | - Yaw Afrane
- Department of Medical Microbiology, University of Ghana, Accra, Ghana
| | - Endalew Zemene
- Tropical and Infectious Diseases Research Center, Jimma University, Jimma, Ethiopia
| | - Delenasaw Yewhalaw
- Tropical and Infectious Diseases Research Center, Jimma University, Jimma, Ethiopia
| | - James W Kazura
- Case Western Reserve University, Cleveland, United States
| | - Guiyun Yan
- Program in Public Health, University of California, Irvine, Irvine, United States
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10
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Mischlinger J, Jochum J, Ramharter M, Kurth F. [Malaria and its importance in travel medicine]. Dtsch Med Wochenschr 2022; 147:745-755. [PMID: 35672022 DOI: 10.1055/a-1661-3783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Malaria remains one of the most important infectious diseases worldwide. The annual number of cases is currently estimated at around 240 million globally, of which more than 500,000 cases are fatal. The majority of malaria cases in Europe are imported from the African continent. Plasmodium falciparum, the causative agent of malaria tropica, causes 75-90 % of all infections imported to Germany. Artemisinin-based combination therapies are the standard treatment for uncomplicated malaria worldwide. In addition to uncomplicated malaria infections, Plasmodium falciparum can cause severe malaria, characterized by vital organ dysfunction and hyperparasitaemia. The treatment of choice for severe malaria is parenteral artesunate. For all patients presenting with febrile illness after a stay in a malaria-endemic area malaria must be ruled out immediately. Microscopy of the thick drop remains the gold standard for diagnosis in clinical routine.
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11
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Momenbeitollahi N, Aggarwal R, Strohle G, Bouriayee A, Li H. Extracellular Vesicle (EV) Dot Blotting for Multiplexed EV Protein Detection in Complex Biofluids. Anal Chem 2022; 94:7368-7374. [PMID: 35533397 DOI: 10.1021/acs.analchem.2c00846] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Extracellular vesicles (EVs) are nanoscale vesicles secreted from cells, carrying biomolecular cargos similar to their cells of origin. Measuring the protein content of EVs in biofluids can offer a crucial insight into human health and disease. For example, detecting tumor-derived EVs' protein markers can aid in early diagnosis of cancer, which is life-saving. In order to use these EV proteins for diagnosis, sensitive and multiplexed methods are required. The current methods for EV protein detection typically require large sample consumption due to challenges with sensitivity and often need an EV isolation step for complex biofluid samples such as blood plasma. In this work, we have developed a simple and sensitive method for multiplexed detection of protein markers on EV membrane surfaces, which we call "EV dot blotting", inspired by conventional dot blotting techniques. After optimization of multiple factors such as antibody concentration, blocking reagent, type of 3D membranes, and use of gold nanoparticles for signal enhancement, cancer-cell-derived EVs were spiked in pooled normal human plasma for conducting a multiplexed assay in a microarray format. Without the need of isolating EVs from blood plasma, a limit of detection of 3.1 × 105 EVs/mL or 1863 EVs/sample was achieved for CD9 protein, 4.7 × 104 EVs/mL or 281 EVs/sample for CD24, and 9.0 × 104 EVs/mL or 538 EVs/sample for EpCAM, up to 4 orders of magnitude lower than those of conventional ELISA. This platform offers sensitive, multiplexed, simple, and low-cost EV protein detection directly from complex biofluids with minimal sample consumption, providing a useful tool for multiplexed EV protein quantification for a variety of applications.
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Affiliation(s)
| | - Roshan Aggarwal
- School of Engineering, University of Guelph, Guelph, Ontario N1G2W1, Canada
| | - Gisela Strohle
- School of Engineering, University of Guelph, Guelph, Ontario N1G2W1, Canada
| | - Amirashkan Bouriayee
- School of Engineering, University of Guelph, Guelph, Ontario N1G2W1, Canada.,Department of Biomedical Sciences, University of Guelph, Guelph, Ontario N1G2W1, Canada
| | - Huiyan Li
- School of Engineering, University of Guelph, Guelph, Ontario N1G2W1, Canada
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12
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Sood SK, Rawat KS, Kumar D. Analytical mapping of information and communication technology in emerging infectious diseases using CiteSpace. TELEMATICS AND INFORMATICS 2022; 69:101796. [PMID: 35282387 PMCID: PMC8901238 DOI: 10.1016/j.tele.2022.101796] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Revised: 01/24/2022] [Accepted: 02/28/2022] [Indexed: 11/05/2022]
Abstract
The prevalence of severe infectious diseases has become a major global health concern. Currently, the COVID-19 outbreak has spread across the world and has created an unprecedented humanitarian crisis. The proliferation of novel viruses has put traditional health systems under immense pressure and posed several serious issues. Henceforth, early detection, identification, rapid testing, and advanced surveillance systems are required to address public health emergencies. However, Information and Communication Technology (ICT) tackles several issues raised by this pandemic and significantly improves the quality of services in the health care sector. This paper presents an ICT-assisted scientometric analysis of infectious diseases, namely, airborne, food & waterborne, fomite-borne, sexually transmitted illnesses, and vector-borne illnesses. It assesses the international research status of this field in terms of citation structure, prolific journals, and country contributions. It has used the CiteSpace tool to address the visualization needs and in-depth insights of scientific literature to pinpoint core hotspots, research frontiers, emerging research areas, and ICT trends. The research finding reveals that mobile apps, telemedicine, and artificial intelligence technologies have greater scope to reduce the threats of infectious diseases. COVID-19, influenza, HIV, and malaria viruses have been identified as research hotspots whereas COVID-19, contact tracing applications, security and privacy concerns about users' data are the recent challenges in this field that need to address. The United States has produced higher research output in all domains of infectious diseases. Furthermore, it explores the co-occurrence network analysis and intellectual landscape of each domain of infectious diseases. It provides potential research directions and insightful clues to researchers and the academic fraternity for further research.
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Affiliation(s)
- Sandeep Kumar Sood
- Department of Computer Aplications, National Institute of Technology, Kurukshetra, Haryana 136119, India
| | - Keshav Singh Rawat
- Department of Computer Science and Informatics, Central University of Himachal Pradesh, Dharmashala, Himachal Pradesh 176215, India
| | - Dheeraj Kumar
- Department of Computer Science and Informatics, Central University of Himachal Pradesh, Dharmashala, Himachal Pradesh 176215, India,Corresponding author
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13
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Izere C, Niyigena J, Tuyishime JDD, Nshimiyimana A, Habyarimana T, Ndishimye P, Yadufashije C, Niyonzima FN. Correlation of Malaria Rapid Test and Peripheral Blood Smear Microscopy among Patients attending Byumba Health Centre. East Afr Health Res J 2022; 6:203-207. [PMID: 36751677 PMCID: PMC9887511 DOI: 10.24248/eahrj.v6i2.700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 11/25/2022] [Indexed: 01/02/2023] Open
Abstract
Background Malaria presents a diagnostic challenge in most tropical countries including Rwanda. Microscopy remains the gold standard for diagnosing malaria, however, it is labour intensive and depends upon the skill of the examiner. Malaria rapid diagnostic tests (MRDTs) have been developed as an easy, convenient alternative to microscopy. Methods A cross sectional study was conducted from October to November 2019 on 130 febrile patients who were directed to the laboratory department for blood screening for malaria parasites at Byumba Health centre. The main objective of this study was to correlate Microscopy and MRDTs in diagnosis of malaria. Results After signing a consent form, blood samples were collected and screened for malaria parasites microscopically and by using MRDTs. Data collection forms were filled with relevant information and obtained results for MRDTs and for peripheral blood smear were recorded. The collected data were statistically analyzed using GraphPad Prism 9 software. The mean age found to be 16 years old. In this study peripheral blood smear microscopy was considered as a reference method. The sensitivity and specificity of RDT Histidine-Rich Protein 2 (HRP-2) were calculated and found to be 96.6% and 60% respectively. The negative predictive value was found to be 92.85% where positive predictive value was 73.3%. Conclusion MRDTs should be used along with microscopy to avert complications associated with delayed diagnosis and similar studies are required to identify alternative techniques with high specificity for the diagnosis of malaria.
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Affiliation(s)
- Cedrick Izere
- Department of Biomedical Laboratory Sciences, Ines-Ruhengeri Institute of Applied Sciences, Musanze district, Northern Province, Rwanda,Correspondence to Cedrick Izere ()
| | - Joyce Niyigena
- Department of Biomedical Laboratory Sciences, Ines-Ruhengeri Institute of Applied Sciences, Musanze district, Northern Province, Rwanda
| | - Jean de Dieu Tuyishime
- Department of Biomedical Laboratory Sciences, Ines-Ruhengeri Institute of Applied Sciences, Musanze district, Northern Province, Rwanda
| | - Alexis Nshimiyimana
- Department of Biomedical Laboratory Sciences, Ines-Ruhengeri Institute of Applied Sciences, Musanze district, Northern Province, Rwanda
| | - Thierry Habyarimana
- Department of Biomedical Laboratory Sciences, Ines-Ruhengeri Institute of Applied Sciences, Musanze district, Northern Province, Rwanda
| | - Pacifique Ndishimye
- Department of Medical Research Center, Rwanda Biomedical Center, Kigali City, Rwanda
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14
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Christopher H, Burns A, Josephat E, Makani J, Schuh A, Nkya S. Using DNA testing for the precise, definite, and low-cost diagnosis of sickle cell disease and other Haemoglobinopathies: findings from Tanzania. BMC Genomics 2021; 22:902. [PMID: 34915846 PMCID: PMC8679995 DOI: 10.1186/s12864-021-08220-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 11/22/2021] [Indexed: 11/30/2022] Open
Abstract
Background Sickle cell disease (SCD) is an important cause of under-five mortality. Tanzania is the 5th country in the world with the highest births prevalence of SCD individuals. Significant advances in the neonatal diagnosis of SCD using rapid point-of-care testing have been made. However genetic confirmation is still required for positive cases, in uncertain cases, in multiply transfused patients, to resolve compound heterozygosity (Hb S/ β0 Thal or Hb S/ β+ thal) not uncommon in the coastal regions of East Africa and increasingly also for pre-marital counselling and potentially for future curative approaches such as gene therapy. The currently available DNA tests are prohibitively expensive. Here, we describe an easy-to-use, affordable and accurate β-globin sequencing approach that can be easily integrated within existing NBS for SCD and other haemoglobinopathies especially in Low- and Middle-income Countries. Aim To evaluate an affordable DNA technology for the diagnosis of Sickle cell disease and other haemoglobinopathies in a resource-limited setting. Methods Laboratory-based validation study was conducted by Muhimbili University of Health and Allied Sciences and the University of Oxford involving sequencing of the entire β -haemoglobin locus using the Oxford Nanopore MinION platform. A total number of 36 Dried blood spots and whole blood samples were subjected to conventional protein-based methods (isoelectric focusing, HPLC), and/or sequenced by the Sanger method as comparators. Results Sequencing results for SCD using the MinION were 100% concordant with those from the Sanger method. In addition, the long-read DNA sequencing method enabled the resolution of cases with unusual phenotypes which make up 1% of all children in Tanzania. The cost is £11/ sample for consumables, which is cheaper compared to other sequencing platforms. Conclusions This is the first report of a comprehensive single DNA assay as a definitive diagnostic test for SCD and other haemoglobinopathies. The test is fast, precise, accurate and affordable.
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Affiliation(s)
- Heavenlight Christopher
- Sickle cell programme, Department of haematology and Blood Transfusion, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania.
| | - Adam Burns
- Oxford Molecular Diagnostics Centre, University of Oxford, Oxford, UK
| | - Emmanuel Josephat
- Sickle cell programme, Department of haematology and Blood Transfusion, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Julie Makani
- Sickle cell programme, Department of haematology and Blood Transfusion, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Anna Schuh
- Sickle cell programme, Department of haematology and Blood Transfusion, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania.,Oxford Molecular Diagnostics Centre, University of Oxford, Oxford, UK
| | - Siana Nkya
- Sickle cell programme, Department of haematology and Blood Transfusion, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania.,Department of Biological Sciences, Dar es Salaam University College of Education (DUCE), Dar es Salaam, Tanzania
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15
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Assessing the Performance of CareStart™ Malaria Rapid Diagnostic Tests in Northwest Ethiopia: A Cross-Sectional Study. J Parasitol Res 2021; 2021:7919984. [PMID: 34725569 PMCID: PMC8556986 DOI: 10.1155/2021/7919984] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 10/05/2021] [Indexed: 11/18/2022] Open
Abstract
Background While rapid diagnostic tests are an alternative diagnostic tests for microscopy in the diagnosis of malaria in rural settings, their performance has been inconsistent. Performance of rapid diagnostic tests might be affected by manufacturing process, transportation and storage, parasitemia level, and skill of personnel who perform the tests. Therefore, periodic evaluation of the local field performance of rapid diagnostic tests is mandatory in order to make early corrections in case of decreased performance. Methods A facility-based cross-sectional study was conducted from January to May 2020 among 257 malaria-suspected patients attending selected health centers in Bahir Dar Zuria district. Capillary blood was collected from each participant and tested for Plasmodium infection by CareStart™ rapid diagnostic test kit and thin and thick blood film microscopy. Data were analyzed using statistical software for social sciences version 20 and MedCalc software version 19.3. Sensitivity, specificity, positive and negative predictive values, and kappa value were calculated to evaluate the performance of rapid diagnostic tests against microscopy. Results Among 257 study participants, 47 (18.3%) were tested positive for Plasmodium infection by at least one of the diagnostic methods. Rapid diagnostic tests revealed 3 false positive and 3 false negative results. The sensitivity and specificity of CareStart Malaria Pf/Pv Combo test were 93.2% and 98.6%, respectively (kappa = 0.918). Conclusion CareStart™ rapid diagnostic test has comparable performance with microscopy for malaria diagnosis. We recommend continued use of CareStart Malaria Pf/Pv Combo test at health posts in Ethiopia where microscopy is not available.
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16
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The Brief Case: A 6-Year-Old with Fever, Abdominal Pain, and Recent Travel to Sierra Leone. J Clin Microbiol 2021; 59:e0053421. [PMID: 34664995 DOI: 10.1128/jcm.00534-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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17
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Boonstra MB, Koelewijn R, Brienen EAT, Silvis W, Stelma FF, Mank TG, Mulder B, van Lieshout L, van Hellemond JJ. Malaria diagnosis in a malaria non-endemic high-resource country: high variation of diagnostic strategy in clinical laboratories in the Netherlands. Malar J 2021; 20:411. [PMID: 34666766 PMCID: PMC8524939 DOI: 10.1186/s12936-021-03889-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 08/20/2021] [Indexed: 11/10/2022] Open
Abstract
Background Microscopic examination of thick and thin blood films is the gold standard in current guidelines for the diagnosis of malaria, but guidelines do not uniformly agree on which combination of other methods should be used and when. Methods Three questionnaires were sent between March 2018 and September 2019 to laboratories subscribing to the external quality assessment scheme for the diagnosis of blood and intestinal parasites of the Dutch Foundation for Quality Assessment in Medical Laboratories in order to investigate how much variation in the laboratory diagnosis of malaria between different clinical laboratories is present in the Netherlands. Results The questionnaires were partially or fully completed by 67 of 77 (87%) laboratories. Only 9 laboratories reported 10 or more malaria positive patients per year. Most laboratories use a different diagnostic strategy, within office versus outside office hours depending on the screening assay result. Within office hours, 62.5% (35/56) of the responding laboratories perform an immunochromatographic test (ICT) in combination with microscopic examination of thick and thin blood films without additional examinations, such as Quantitative Buffy Coat and/or rtPCR analysis. Outside office hours 85.7% (48/56) of laboratories use an ICT as single screening assay and positive results are immediately confirmed by thick and thin blood films without additional examinations (89.6%, 43/48). In case of a negative ICT result outside office hours, 70.8% (34/48) of the laboratories perform microscopic examination of the thick film the next morning and 22.9% (11/48) confirm the negative ICT result immediately. Furthermore, substantial differences were found in the microscopic examinations of thick and thin blood films; the staining, theoretical sensitivity of the thick film and determination of parasitaemia. Conclusions This study demonstrated a remarkably high variation between laboratories in both their diagnostic strategy as well as their methods for microscopic examination for the diagnosis of malaria in a clinical setting, despite existing national and international guidelines. While the impact of these variations on the accuracy of the diagnosis of malaria is yet unknown, these findings should stimulate clinical laboratories to critically review their own diagnostic strategy. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-021-03889-7.
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Affiliation(s)
- Marrit B Boonstra
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Rob Koelewijn
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Eric A T Brienen
- Department of Parasitology, Leiden University Medical Centre, Leiden, The Netherlands
| | - Welmoed Silvis
- Laboratory for Medical Microbiology and Public Health (LabMicTA), Hengelo, The Netherlands
| | - Foekje F Stelma
- Department of Medical Microbiology, Radboudumc, Nijmegen, The Netherlands
| | - Theo G Mank
- Regional Laboratory for Medical Microbiology and Public Health, Haarlem, The Netherlands
| | - Bert Mulder
- Department of Medical Microbiology, Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands
| | - Lisette van Lieshout
- Department of Parasitology, Leiden University Medical Centre, Leiden, The Netherlands
| | - Jaap J van Hellemond
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC University Medical Center, Rotterdam, The Netherlands.
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Michael O, Orimadegun A, Falade C. PERSISTENCE OF PLASMODIUM FALCIPARUM HRP2 ANTIGEN AFTER EFFECTIVE ANTIMALARIAL THERAPY. Ann Ib Postgrad Med 2021; 19:15-21. [PMID: 35330886 PMCID: PMC8935674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Introduction Histidine Rich Protein 2 based (HRP2-based) malaria rapid diagnostic tests (mRDTs) have been shown to perform as well as routine light microscopy, however, they are limited by some factors including persistence of HRP2 antigenemia. In this paper we report the evaluation of an HRP2-based mRDT in a prospective study that enrolled children and followed them up for 28 days. Methods Children aged below five years, with acute episode of fever/pyrexia, were enrolled. The enrolled participants had expert malaria microscopy and RDT done at enrolment (Day 0), and on days 1, 2, 3, 7, 14, 21, and 28. The malaria RDT test was considered positive when the antigen and control lines were visible in their respective windows, negative when only the control band was visible and invalid when the control band was not visible. Faint test lines were considered positive. The RDT results were compared to those of expert microscopy. Results Two hundred and twenty-six children aged 29.2 ± 15.5 months were enrolled. The proportion of children positive by expert malaria microscopy and RDT was 100% and 95.6% respectively. During the 28 day follow up of the children the proportions positive by microscopy and RDT on days 3, 7, 14, and 28 were 1% and 94.6%, 0% and 93.5%, 0% and 91%, and 16.5% and 80.6% respectively. Gender and age dependent analysis of proportion of positive children were similar. Proportion of children with persistence of HRP2 antigen appeared to be lower in those with parasite density below 200/µL, however, this observation requires further evaluation in larger studies. Conclusion the study revealed a high proportion of persistence of HRP2 antigen in the children 28 days after effective antimalarial therapy. Histidine rich protein 2 based malaria rapid diagnostic tests are not recommended for monitoring of antimalarial therapies.
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Affiliation(s)
- O.S. Michael
- Department of Pharmacology and Therapeutics, College of Medicine, University of Ibadan, Nigeria
| | - A.E. Orimadegun
- Institute of Child Health, College of Medicine, University of Ibadan, Nigeria
| | - C.O. Falade
- Department of Pharmacology and Therapeutics, College of Medicine, University of Ibadan, Nigeria
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Liu F, Zou J, Luo X, Liu Y, Huang C, He X, Wang Y. A point-of-care chemiluminescence immunoassay for pepsinogen I enables large-scale community health screening. Anal Bioanal Chem 2021; 413:4493-4500. [PMID: 34041573 DOI: 10.1007/s00216-021-03412-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 05/10/2021] [Accepted: 05/17/2021] [Indexed: 11/28/2022]
Abstract
Pepsinogen I (PGI) can reflect the morphology and function of the gastric mucosa. Accordingly, the large-scale community health screening of PGI can dramatically increase the early diagnosis rate of gastric cancer. However, PGI testing can only be carried out in comprehensive hospitals and health examination centers. To ameliorate this issue, a point-of-care chemiluminescent immunoassay for PGI was developed in a fully automated miniaturized instrument. This instrument was especially developed for health check-ups in the grassroots communities; its volume of which is only 0.18 m3. Critically, the entire detection process for a single sample only requires 20 min, and the samples can be loaded continuously, making the method suitable for high-throughput analysis. The assay displayed an excellent detection limit of 0.048 ng/mL with a broad detection range of 0-200 ng/mL. Furthermore, this assay exhibited high sensitivity and specificity, had low intra- and inter-assay coefficients of variation (<10%), and was not affected after storage at 37 °C for 7 days. The assay was used to detect PGI in 95 clinical serum samples, and the results were highly correlated with those that were clinically tested (correlation coefficient, R2 = 0.998). Hence, the method established in this work has great application value and can be broadly applied for the large-scale screening of gastric cancer in resource-limited areas.
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Affiliation(s)
- Fangfang Liu
- College of Food Science and Engineering, South China University of Technology, Guangzhou, 510640, China
| | - Jingjing Zou
- College of Food Science and Engineering, South China University of Technology, Guangzhou, 510640, China
| | - Xiangxiang Luo
- College of Food Science and Engineering, South China University of Technology, Guangzhou, 510640, China
| | - Yu Liu
- College of Food Science and Engineering, South China University of Technology, Guangzhou, 510640, China
| | - Chunrong Huang
- National & Local United Engineering Lab of Rapid Diagnostic Test, Guangzhou Wondfo Biotech Co., Ltd., Guangzhou, 5l0663, China
| | - Xiaowei He
- College of Food Science and Engineering, South China University of Technology, Guangzhou, 510640, China.
| | - Yu Wang
- Department of Laboratory Medicine, Guangzhou First People's Hospital, the Second Affiliated Hospital of South China University of Technology, Guangzhou, 510180, China.
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20
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Nolder D, Stewart L, Tucker J, Ibrahim A, Gray A, Corrah T, Gallagher C, John L, O'Brien E, Aggarwal D, Benavente ED, van Schalkwyk D, Henriques G, Sepúlveda N, Campino S, Chiodini P, Sutherland C, Beshir KB. Failure of rapid diagnostic tests in Plasmodium falciparum malaria cases among travelers to the UK and Ireland: Identification and characterisation of the parasites. Int J Infect Dis 2021; 108:137-144. [PMID: 33991679 PMCID: PMC8295040 DOI: 10.1016/j.ijid.2021.05.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 05/05/2021] [Accepted: 05/07/2021] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVES Our objective was to systematically investigate false-negative histidine-rich protein 2 rapid diagnostic tests (HRP2-RDT) in imported Plasmodium falciparum malaria cases from travelers to the UK and the Republic of Ireland (RoI). METHODS Five imported malaria cases in travellers returning to the UK and RoI from East Africa were reported to the PHE Malaria Reference Laboratory as negative according to histidine-rich protein (HRP2)-RDT. The cases were systematically investigated using microscopic, RDT, molecular, genomic, and in in vitro approaches. RESULTS In each case, HRP2-RDT was negative, whereas microscopy confirmed the presence of P. falciparum. Further analysis revealed that the genes encoding HRP2 and HRP3 were deleted in three of the five cases. Whole-genome sequencing in one of these isolates confirmed deletions in P. falciparum chromosomes 8 and 13. Our study produced evidence that the fourth case, which had high parasitemia at clinical presentation, was a rare example of antigen saturation ('prozone-like effect'), leading to a false negative in the HRP2-RDT, while the fifth case was due to low parasitemia. CONCLUSIONS False-negative HRP2-RDT results with P. falciparum are concerning. Our findings emphasise the necessity of supporting the interpretation of RDT results with microscopy, in conjunction with clinical observations, and sets out a systematic approach to identifying parasites carrying pfhrp2 and pfhrp3 deletions.
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Affiliation(s)
- Debbie Nolder
- PHE Malaria Reference Laboratory, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Lindsay Stewart
- PHE Malaria Reference Laboratory, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK; Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Julie Tucker
- PHE Malaria Reference Laboratory, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Amy Ibrahim
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Adam Gray
- Department of Infectious Diseases, Northwick Park Hospital, London North West University Healthcare NHS Trust, London HA1 3UJ, UK
| | - Tumena Corrah
- Department of Infectious Diseases, Northwick Park Hospital, London North West University Healthcare NHS Trust, London HA1 3UJ, UK
| | - Carmel Gallagher
- Department of Infectious Diseases, Northwick Park Hospital, London North West University Healthcare NHS Trust, London HA1 3UJ, UK
| | - Laurence John
- Department of Infectious Diseases, Northwick Park Hospital, London North West University Healthcare NHS Trust, London HA1 3UJ, UK
| | - Edel O'Brien
- Haematology Lab, University Hospital Limerick, Ireland
| | - Dinesh Aggarwal
- Department of Clinical Parasitology, Hospital for Tropical Diseases, University College London Hospitals NHS Foundation Trust, London, UK
| | - Ernest Diez Benavente
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Donelly van Schalkwyk
- PHE Malaria Reference Laboratory, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK; Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Gisela Henriques
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Nuno Sepúlveda
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK; CEAUL - Centro de Estatística e Aplicações da Universidade de Lisboa, Lisbon, Portugal
| | - Susana Campino
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Peter Chiodini
- PHE Malaria Reference Laboratory, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK; Department of Clinical Parasitology, Hospital for Tropical Diseases, University College London Hospitals NHS Foundation Trust, London, UK
| | - Colin Sutherland
- PHE Malaria Reference Laboratory, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK; Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Khalid B Beshir
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK.
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Malaria Rapid Diagnostic Tests: Literary Review and Recommendation for a Quality Assurance, Quality Control Algorithm. Diagnostics (Basel) 2021; 11:diagnostics11050768. [PMID: 33922917 PMCID: PMC8145891 DOI: 10.3390/diagnostics11050768] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 04/20/2021] [Accepted: 04/21/2021] [Indexed: 01/24/2023] Open
Abstract
Malaria rapid diagnostic tests (RDTs) have had an enormous global impact which contributed to the World Health Organization paradigm shift from empiric treatment to obtaining a parasitological diagnosis prior to treatment. Microscopy, the classic standard, requires significant expertise, equipment, electricity, and reagents. Alternatively, RDT’s lower complexity allows utilization in austere environments while achieving similar sensitivities and specificities. Worldwide, there are over 200 different RDT brands that utilize three antigens: Plasmodium histidine-rich protein 2 (PfHRP-2), Plasmodium lactate dehydrogenase (pLDH), and Plasmodium aldolase (pALDO). pfHRP-2 is produced exclusively by Plasmodium falciparum and is very Pf sensitive, but an alternative antigen or antigen combination is required for regions like Asia with significant Plasmodium vivax prevalence. RDT sensitivity also decreases with low parasitemia (<100 parasites/uL), genetic variability, and prozone effect. Thus, proper RDT selection and understanding of test limitations are essential. The Center for Disease Control recommends confirming RDT results by microscopy, but this is challenging, due to the utilization of clinical laboratory standards, like the College of American Pathologists (CAP) and the Clinical Lab Improvement Act (CLIA), and limited recourses. Our focus is to provide quality assurance and quality control strategies for resource-constrained environments and provide education on RDT limitations.
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Dejazmach Z, Alemu G, Yimer M, Muluneh C, Tegegne B. Evaluation of the performance of health extension workers on malaria rapid diagnostic tests and predictor factors in Bahir Dar Zuria district, northwest Ethiopia: A cross-sectional study. PLoS One 2021; 16:e0249708. [PMID: 33831059 PMCID: PMC8031431 DOI: 10.1371/journal.pone.0249708] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Accepted: 03/23/2021] [Indexed: 11/19/2022] Open
Abstract
Background In Ethiopia, anti-malaria treatment is initiated after parasitological confirmation using blood film microscopy at health centers and hospitals, or serological rapid diagnostic tests at health posts. At health posts, the diagnosis is performed by health extension workers using rapid diagnostic tests after little training. However, there is paucity of data about the health extension workers’ performance on rapid diagnostic tests. Hence, periodic monitoring of the performances of health extension workers on malaria rapid diagnostic tests and predicted factors plays a pivotal role for the control of malaria. Methods A cross sectional study was conducted in May 2020, among 75 health extension workers working at health posts in Bahir Dar Zuria district, Northwest Ethiopia. Their performance on malaria rapid diagnostic tests was assessed by distributing known positive and negative samples as confirmed by investigators using both rapid diagnostic test and blood film microscopy. Test results from health extension workers were then compared with that of investigators. Procedural errors committed while performing the tests were assessed using observational checklist. Data were analyzed using SPSS software version 20. Results The overall sensitivity and specificity of health extension workers in detecting Plasmodium species were 96.8% and 98.7%, respectively with 97.3% result agreement between the health extension workers and investigators (kappa value = 0.949). The most common procedural errors committed by health extension workers was ‘not checking expiry date of the test kits’ followed by ‘not adhering to the appropriate time of reading results’ that 70.7% and 64% of the participants committed these errors, respectively. Total number of procedural errors committed by those who have got in-service training was decreased by 47.3% as compared to those without in-service training. Conclusions Health extension workers had high performance on malaria rapid diagnostic tests. However, in-service training and periodic supervision should be given in order to maximize performance on these tests.
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Affiliation(s)
- Zelalem Dejazmach
- Department of Medical Laboratory Science, College of Health Sciences, Woldia University, Woldia, Ethiopia
- * E-mail:
| | - Getaneh Alemu
- Department of Medical Laboratory Science, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia
| | - Mulat Yimer
- Department of Medical Laboratory Science, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia
- Medical Parasitology, Amhara Public Health Institute, Bahir Dar, Ethiopia
| | - Chalachew Muluneh
- Medical Parasitology and Vector Control, Bahir Dar Zuria Woreda Health Office, Bahir Dar, Ethiopia
| | - Banchamlak Tegegne
- Medical Parasitology, Amhara Public Health Institute, Bahir Dar, Ethiopia
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Kim J, Lim DH, Mihn DC, Nam J, Jang WS, Lim CS. Clinical Usefulness of LabChip Real-time PCR using Lab-On-a-Chip Technology for Diagnosing Malaria. THE KOREAN JOURNAL OF PARASITOLOGY 2021; 59:77-82. [PMID: 33684990 PMCID: PMC7939964 DOI: 10.3347/kjp.2021.59.1.77] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 11/30/2020] [Accepted: 12/06/2020] [Indexed: 12/29/2022]
Abstract
As malaria remains a major health problem worldwide, various diagnostic tests have been developed, including microscopy-based and rapid diagnostic tests. LabChip real-time PCR (LRP) is a small and portable device used to diagnose malaria using lab-on-a-chip technology. This study aimed to evaluate the diagnostic performance of LRP for detecting malaria parasites. Two hundred thirteen patients and 150 healthy individuals were enrolled from May 2009 to October 2015. A diagnostic detectability of LRP for malaria parasites was compared to that of conventional RT-PCR. Sensitivity of LRP for Plasmodium vivax, P. falciparum, P. malariae, and P. ovale was 95.5%, 96.0%, 100%, and 100%, respectively. Specificity of LRP for P. vivax, P. falciparum, P. malariae, and P. ovale was 100%, 99.3%, 100%, and 100%, respectively. Cohen's Kappa coefficients between LRP and CFX96 for detecting P. vivax, P. falciparum, P. malariae, and P. ovale were 0.96, 0.98, 1.00, and 1.00, respectively. Significant difference was not observed between the results of LRP and conventional RT-PCR and microscopic examination. A time required to amplify DNAs using LRP and conventional RT-PCR was 27 min and 86 min, respectively. LRP amplified DNAs 2 times more fast than conventional RT-PCR due to the faster heat transfer. Therefore, LRP could be employed as a useful tool for detecting malaria parasites in clinical laboratories.
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Affiliation(s)
- Jeeyong Kim
- Department of Laboratory Medicine, Korea University College of Medicine, Seoul 08308, Korea
| | - Da Hye Lim
- Department of Laboratory Medicine, Korea University College of Medicine, Seoul 08308, Korea
| | - Do-CiC Mihn
- Department of Diagnostic Immunology, Seegene Medical Foundation, Seoul 04805, Korea
| | - Jeonghun Nam
- Department of Laboratory Medicine, Korea University College of Medicine, Seoul 08308, Korea
| | - Woong Sik Jang
- Department of Laboratory Medicine, Korea University College of Medicine, Seoul 08308, Korea
| | - Chae Seung Lim
- Department of Laboratory Medicine, Korea University College of Medicine, Seoul 08308, Korea
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Galatas B, Mayor A, Gupta H, Balanza N, Jang IK, Nhamussua L, Simone W, Cisteró P, Chidimatembue A, Munguambe H, Saúte F, Aide P, Bassat Q. Field performance of ultrasensitive and conventional malaria rapid diagnostic tests in southern Mozambique. Malar J 2020; 19:451. [PMID: 33287822 PMCID: PMC7720469 DOI: 10.1186/s12936-020-03526-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 11/26/2020] [Indexed: 01/01/2023] Open
Abstract
Background An ultrasensitive malaria rapid diagnostic test (RDT) was recently developed for the improved detection of low-density Plasmodium falciparum infections. This study aimed to compare the diagnostic performance of the PfHRP2-based Abbott Malaria Ag P. falciparum ultrasensitive RDT (uRDT) to that of the conventional SD-Bioline Malaria Ag P. falciparum RDT (cRDT) when performed under field conditions. Methods Finger-prick blood samples were collected from adults and children in two cross-sectional surveys in May of 2017 in southern Mozambique. Using real-time quantitative PCR (RT-qPCR) as the reference method, the age-specific diagnostic performance indicators of the cRDT and uRDT were compared. The presence of histidine-rich protein 2 (HRP2) and Plasmodium lactate dehydrogenase (pLDH) antigens was evaluated in a subset from dried blood spots by a quantitative antigen assay. pfhrp2 and pfhrp3 gene deletions were assessed in samples positive by RT-qPCR and negative by both RDTs. Results Among the 4,396 participants with complete test results, the sensitivity of uRDTs (68.2; 95% CI 60.8 to 74.9) was marginally better than that of cRDTs (61.5; 95% CI 53.9 to 68.6) (p-value = 0.004), while the specificities were similar (uRDT: 99.0 [95% CI 98.6 to 99.2], cRDT: 99.2 [95% CI 98.9 to 99.4], p-value = 0.02). While the performance of both RDTs was lowest in ≥ 15-year-olds, driven by the higher prevalence of low parasite density infections in this group, the sensitivity of uRDTs was significantly higher in this age group (54.9, 95% CI 40.3 to 68.9) compared to the sensitivity of cRDTs (39.2, 95% CI 25.8 to 53.9) (p-value = 0.008). Both RDTs detected P. falciparum infections at similar geometric mean parasite densities (112.9 parasites/μL for uRDTs and 145.5 parasites/μL for cRDTs). The presence of HRP2 antigen was similar among false positive (FP) samples of both tests (80.5% among uRDT-FPs and 84.4% among cRDT-FPs). Only one false negative sample was detected with a partial pfhrp2 deletion. Conclusion This study showed that the uRDTs developed by Abbott do not substantially outperform SD-Bioline Pf malaria RDTs in the community and are still not comparable to molecular methods to detect P. falciparum infections in this study setting.
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Affiliation(s)
- Beatriz Galatas
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain. .,Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique.
| | - Alfredo Mayor
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain.,Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique.,CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | - Himanshu Gupta
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain.,Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Núria Balanza
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | | | - Lidia Nhamussua
- Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique
| | - Wilson Simone
- Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique
| | - Pau Cisteró
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | | | | | - Francisco Saúte
- Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique
| | - Pedro Aide
- Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique.,National Institute of Health, Ministry of Health, Maputo, Mozambique
| | - Quique Bassat
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain.,Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique.,CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain.,ICREA, Pg. Lluís Companys 23, 08010, Barcelona, Spain.,Pediatric Infectious Diseases Unit, Pediatrics Department, Hospital Sant Joan de Déu (University of Barcelona), Barcelona, Spain
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Varo R, Balanza N, Mayor A, Bassat Q. Diagnosis of clinical malaria in endemic settings. Expert Rev Anti Infect Ther 2020; 19:79-92. [PMID: 32772759 DOI: 10.1080/14787210.2020.1807940] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
INTRODUCTION Malaria continues to be a major global health problem, with over 228 million cases and 405,000 deaths estimated to occur annually. Rapid and accurate diagnosis of malaria is essential to decrease the burden and impact of this disease, particularly in children. We aimed to review the main available techniques for the diagnosis of clinical malaria in endemic settings and explore possible future options to improve its rapid recognition. AREAS COVERED literature relevant to malaria diagnosis was identified through electronic searches in Pubmed, with no language or date restrictions and limited to humans. EXPERT OPINION Light microscopy is still considered the gold standard method for malaria diagnosis and continues to be at the frontline of malaria diagnosis. However, technologies as rapid diagnostic tests, mainly those who detect histidine-rich protein-2, offer an accurate, rapid and affordable alternative for malaria diagnosis in endemic areas. They are now the technique most extended in endemic areas for parasitological confirmation. In these settings, PCR-based assays are usually restricted to research and they are not currently helpful in the management of clinical malaria. Other technologies, such as isothermal methods could be an interesting and alternative approach to PCR in the future.
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Affiliation(s)
- Rosauro Varo
- ISGlobal, Hospital Clínic - Universitat De Barcelona , Barcelona, Spain.,Centro De Investigação Em Saúde De Manhiça (CISM) , Maputo, Mozambique
| | - Núria Balanza
- ISGlobal, Hospital Clínic - Universitat De Barcelona , Barcelona, Spain
| | - Alfredo Mayor
- ISGlobal, Hospital Clínic - Universitat De Barcelona , Barcelona, Spain.,Centro De Investigação Em Saúde De Manhiça (CISM) , Maputo, Mozambique
| | - Quique Bassat
- ISGlobal, Hospital Clínic - Universitat De Barcelona , Barcelona, Spain.,Centro De Investigação Em Saúde De Manhiça (CISM) , Maputo, Mozambique.,ICREA, Pg. Lluís Companys 23 , Barcelona, Spain.,Pediatric Infectious Diseases Unit, Pediatrics Department, Hospital Sant Joan De Deu (University of Barcelona) , Barcelona, Spain.,Consorcio De Investigación Biomédica En Red De Epidemiología Y Salud Publica (CIBERESP) , Madrid, Spain
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Candel FJ, Viñuela-Prieto JM, González Del Castillo J, Barreiro García P, Fragiel Saavedra M, Hernández Píriz A, Jiménez Virumbrales D, Canora Lebrato J, García de Casasola G, Gil Prieto R, San-Román Montero J, Ortega Anselmi J, Barba Martín R, Prados Roa F, Marco Martínez J, Zapatero Gaviria A. Utility of lateral flow tests in SARS-CoV-2 infection monitorization. REVISTA ESPANOLA DE QUIMIOTERAPIA : PUBLICACION OFICIAL DE LA SOCIEDAD ESPANOLA DE QUIMIOTERAPIA 2020; 33:258-266. [PMID: 32492991 PMCID: PMC7374028 DOI: 10.37201/req/052.2020] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 06/01/2020] [Accepted: 06/03/2020] [Indexed: 12/15/2022]
Abstract
OBJECTIVE The diagnosis of SARS-CoV-2 infection is crucial for medical and public health reasons, to allow the best treatment of cases and the best control of the pandemic. Serology testing allows for the detection of asymptomatic infections and 19-COVID cases once the virus has been cleared. We analyzed the usefulness of the SARS-CoV-2 rapid test of Autobio and tried to correlate its pattern with the severity of COVID19 infection. METHODS We analyzed the accuracy and clinical usefulness of a point-of-care IgM and/or IgG test for SARS-CoV-2 in 35 COVID-19 patients [12 (34.3%) mild-moderate and 23 (65.7%) severe-critical] admitted to a field hospital in Madrid, as well as in 5 controls. RESULTS The mean time from the first day of symptoms to the antibody test was 28 days (SD: 8.7), similar according to the severity of the disease. All patients with SARS-CoV-2 PCR+ showed the corresponding IgG positivity, while these results were negative in all control individuals. A total of 26 (74%) cases also presented with positive IgM, 19 (83%) were severe-critical cases and 7 (58%) were mild-moderate cases. The IgM response lasted longer in the severe critical cases (mean: 29.7 days; SD: 8.4) compared to the moderate cases (mean: 21.2 days; SD: 2.0).. CONCLUSIONS Rapid serology tests are useful for the diagnosis of patients with COVID-19 (mainly IgG detection) and may also be correlated with the severity of the infection (based on IgM detection).
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Affiliation(s)
- F J Candel
- Francisco Javier Candel González. Clinical Microbiology and Infectious Diseases. Hospital Clínico San Carlos. Madrid. Spain. COVID-19 IFEMA Field Hospital.
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Krockenberger MB, Marschner C, Martin P, Reppas G, Halliday C, Schmertmann LJ, Harvey AM, Malik R. Comparing immunochromatography with latex antigen agglutination testing for the diagnosis of cryptococcosis in cats, dogs and koalas. Med Mycol 2020; 58:39-46. [PMID: 31220311 DOI: 10.1093/mmy/myz010] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 11/07/2018] [Accepted: 02/14/2019] [Indexed: 11/13/2022] Open
Abstract
Although the point-of-care cryptococcal antigen lateral flow assay (LFA) has revolutionized the diagnosis of cryptococcosis in human patients, to date there has been no large-scale examination of this test in animals. We therefore assessed the LFA in cats, dogs and koalas suspected of having cryptococcosis. In sum, 528 serum specimens (129 from cats, 108 from dogs, 291 from koalas) were tested using the LFA and one of two commercially available latex cryptococcal antigen agglutination test (LCAT) kits. The LCAT is a proven and well-accepted method in veterinary patients and therefore taken as the "gold standard" against which the LFA was compared. The LFA achieved a sensitivity of 92%, 100%, and 98% in cats, dogs, and koalas, respectively, with corresponding negative predictive values of 94%, 100%, and 98%. The specificity of the LFA was 81%, 84%, and 62% for cats, dogs, and koalas, respectively, with corresponding positive predictive values of 76%, 48%, and 69%. These findings suggest the most appropriate role for the LFA is as a screening test to rule out a diagnosis of cryptococcosis in cats, dogs, and koalas. Point-of-care accessibility makes it equally suited for use in the field and as a cage-side test in veterinary hospitals. The suboptimal specificity of the LFA makes it less suited to definitive confirmation of cryptococcosis in animals; therefore, all LFA-positive test results should be confirmed by LCAT testing. The discrepancy between these observations and the high specificity of the LFA in humans may reflect differences in the host-pathogen interactions amongst the species.
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Affiliation(s)
- Mark B Krockenberger
- Veterinary Pathology Diagnostic Services, Sydney School of Veterinary Science, McMaster Building, B14, University of Sydney NSW Australia 2006
| | - Caroline Marschner
- Veterinary Pathology Diagnostic Services, Sydney School of Veterinary Science, McMaster Building, B14, University of Sydney NSW Australia 2006
| | - Patricia Martin
- Veterinary Pathology Diagnostic Services, Sydney School of Veterinary Science, McMaster Building, B14, University of Sydney NSW Australia 2006
| | - George Reppas
- Vetnostics, 60 Waterloo Rd, North Ryde, NSW Australia 2113
| | - Catriona Halliday
- Clinical Mycology Reference Laboratory, CIDMLS - NSW Health Pathology, Level 3, ICPMR, Westmead Hospital, Westmead, NSW Australia
| | - Laura J Schmertmann
- Veterinary Pathology Diagnostic Services, Sydney School of Veterinary Science, McMaster Building, B14, University of Sydney NSW Australia 2006
| | | | - Richard Malik
- Centre for Veterinary Education, Veterinary Science Conference Centre, B22, University of Sydney NSW Australia 2006; Adjunct Professor Charles Sturt University
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Ogunfowokan O, Ogunfowokan BA, Nwajei AI. Sensitivity and specificity of malaria rapid diagnostic test (mRDT CareStatTM) compared with microscopy amongst under five children attending a primary care clinic in southern Nigeria. Afr J Prim Health Care Fam Med 2020; 12:e1-e8. [PMID: 32634015 PMCID: PMC7380062 DOI: 10.4102/phcfm.v12i1.2212] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 11/03/2019] [Accepted: 11/09/2019] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND Malaria diagnosis using microscopy is currently the gold standard. However, malaria rapid diagnostic tests (mRDTs) were developed to simplify the diagnosis in regions without access to functional microscopy. AIM The objective of this study was to compare the diagnostic accuracy of mRDT CareStatTM with microscopy. SETTING This study was conducted in the paediatric primary care clinic of the Federal Medical Centre, Asaba, Nigeria. METHODS A cross-sectional study for diagnostic accuracy was conducted from May 2016 to October 2016. Ninety-eight participants were involved to obtain a precision of 5%, sensitivity of mRDT CareStatTM of 95% from published work and 95% level of confidence after adjusting for 20% non-response rate or missing data. Consecutive participants were tested using both microscopy and mRDT. The results were analysed using EPI Info Version 7. RESULTS A total of 98 children aged 3-59 months were enrolled. Malaria prevalence was found to be 53% (95% confidence interval [CI] = 46% - 60%), whilst sensitivity and specificity were 29% (95% CI = 20% - 38%) and 89% (95% CI = 83% - 95%), respectively. The positive and negative predictive values were 75% (95% CI = 66.4% - 83.6%) and 53% (95% CI = 46% - 60%), respectively. CONCLUSION Agreement between malaria parasitaemia using microscopy and mRDT positivity increased with increase in the parasite density. The mRDT might be negative when malaria parasite density using microscopy is low.
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Chawla SS, Gorakshakar AC, Ghosh KK, Madkaikar MR, Devarajan PV. Fabrication of gelatin functionalized silver nanoparticles for blood group profiling. NANOTECHNOLOGY 2020; 31:295102. [PMID: 32213681 DOI: 10.1088/1361-6528/ab83b9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We report the fabrication of silver nanoparticles (AgNPs) surface functionalized with gelatin at different concentrations (G10/G20/G40 AgNPs) with an average particle size of ∼200 nm, bioconjugated with antisera antibodies (AsAbs) of the major and clinically significant blood groups (CSBGs) at different titres from neat to 1:128. Bioconjugation using ionic interaction at pH 7.4 enabled 'end-on' configuration, with the -NH2 group of the antibody free for interaction with the red blood cell antigen, as confirmed by Fourier transform infrared spectroscopy. The tube agglutination test (TAT) revealed optimum agglutination with G20NPs, while SDS PAGE confirmed the optimal titre as 1:8 for the major blood groups A, B, AB and O. Bioconjugated AgNPs coated onto microtitre assay plates with the major blood groups and CSBGs to enable simultaneous identification, were validated against the TAT on 400 random blood samples for the major blood groups and revealed high accuracy (95%). While similar accuracy was seen for most of the CSBGs with only false negatives, the method was not found to be suitable for the Kell, Kidd and Duffy groups. The absence of false positives reflects high safety, and eliminates the risk of a mismatched blood transfusion. The method uses diluted blood and hence could enable point-of-care detection. The significantly lower AsAb requirement also provides a cost advantage.
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Affiliation(s)
- Shweta S Chawla
- Department of Pharmaceutical Sciences, Institute of Chemical Technology, Mumbai, India
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Imported Malaria in Countries where Malaria Is Not Endemic: a Comparison of Semi-immune and Nonimmune Travelers. Clin Microbiol Rev 2020; 33:33/2/e00104-19. [PMID: 32161068 DOI: 10.1128/cmr.00104-19] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The continuous increase in long-distance travel and recent large migratory movements have changed the epidemiological characteristics of imported malaria in countries where malaria is not endemic (here termed non-malaria-endemic countries). While malaria was primarily imported to nonendemic countries by returning travelers, the proportion of immigrants from malaria-endemic regions and travelers visiting friends and relatives (VFRs) in malaria-endemic countries has continued to increase. VFRs and immigrants from malaria-endemic countries now make up the majority of malaria patients in many nonendemic countries. Importantly, this group is characterized by various degrees of semi-immunity to malaria, resulting from repeated exposure to infection and a gradual decline of protection as a result of prolonged residence in non-malaria-endemic regions. Most studies indicate an effect of naturally acquired immunity in VFRs, leading to differences in the parasitological features, clinical manifestation, and odds for severe malaria and clinical complications between immune VFRs and nonimmune returning travelers. There are no valid data indicating evidence for differing algorithms for chemoprophylaxis or antimalarial treatment in semi-immune versus nonimmune malaria patients. So far, no robust biomarkers exist that properly reflect anti-parasite or clinical immunity. Until they are found, researchers should rigorously stratify their study results using surrogate markers, such as duration of time spent outside a malaria-endemic country.
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HRP2: Transforming Malaria Diagnosis, but with Caveats. Trends Parasitol 2020; 36:112-126. [DOI: 10.1016/j.pt.2019.12.004] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 11/29/2019] [Accepted: 12/02/2019] [Indexed: 11/23/2022]
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Amoah LE, Donu D, Abuaku B, Ahorlu C, Arhinful D, Afari E, Malm K, Koram KA. Probing the composition of Plasmodium species contained in malaria infections in the Eastern region of Ghana. BMC Public Health 2019; 19:1617. [PMID: 31791319 PMCID: PMC6889690 DOI: 10.1186/s12889-019-7989-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 11/21/2019] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND Asymptomatic falciparum and non-falciparum malaria infections are major challenges to malaria control interventions, as they remain a source of continual infection in the community. This becomes even more important as the debate moves towards elimination and eradication. This study sought to quantify the burden of Plasmodium malaria infection in seven communities in the Eastern Region of Ghana. METHODS The cross-sectional study recruited 729 participants aged 85 years old and below from 7 closely linked communities. Finger pricked blood was used to prepare thick and thin blood smears as well as spot filter paper and an histidine rich protein 2 (HRP2) rapid diagnostic test kit (RDT). Genomic DNA was extracted from the filter paper dry blood spot (DBS) and used in PCR to amplify the Plasmodium 18S rRNA gene using species specific PCR. RESULTS 96.6% of the participants were identified as afebrile, with axillary temperatures below 37.5 °C. PCR identified 66% of the participants to harbor malaria parasites, with 9 P. malariae and 7 P. ovale mono-infections accounting for 2.2% and P. falciparum combined with either 36 P. malariae or 25 P. ovale infections, accounting for 13.3%. Parasite prevalence by microscopy (32%) was similar to the RDT positivity rate (33%). False positive RDT results ranged from 64.6% in children aged between 5 and 9 years to 10% in adults aged 20 years and above. No significant differences were observed in falciparum and non-falciparum parasite carriage at the community level, however young adults aged between 15 and 19 years had the highest prevalence (34.8% (16/46)) of P. falciparum and P. malariae parasite carriage whilst children aged between 5 and 9 years had the highest level (11.4% (14/123)) of P. ovale carriage. CONCLUSION The high rate of misidentification of non-falciparum parasites and the total absence of detection of P. ovale by microscopy suggests that more sensitive malaria diagnostic tools including molecular assays are required to accurately determine the prevalence of carriers of non-falciparum parasites and low density P. falciparum infections, especially during national surveillance exercises. Additionally, malaria control interventions targeting the non-falciparum species P. malariae and P. ovale parasites are needed.
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Affiliation(s)
- Linda Eva Amoah
- Immunology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana. .,West Africa Center for Cell biology of Infectious Pathogens (WACCBIP), College of Basic and Applied Sciences, University of Ghana, Accra, Ghana.
| | - Dickson Donu
- Immunology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Benjamin Abuaku
- Epidemiology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Colins Ahorlu
- Epidemiology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Daniel Arhinful
- Epidemiology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Edwin Afari
- School of Public Health, University of Ghana, Accra, Ghana
| | - Keziah Malm
- National Malaria Control Program, Accra, Ghana
| | - Kwadwo Ansah Koram
- West Africa Center for Cell biology of Infectious Pathogens (WACCBIP), College of Basic and Applied Sciences, University of Ghana, Accra, Ghana.,Epidemiology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
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Kamaliddin C, Le Bouar M, Berry A, Fenneteau O, Gillet P, Godineau N, Candolfi E, Houzé S. Assessment of diagnostic methods for imported malaria in mainland France. Med Mal Infect 2019; 50:141-160. [PMID: 31375372 DOI: 10.1016/j.medmal.2019.07.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 07/04/2019] [Indexed: 12/29/2022]
Affiliation(s)
- C Kamaliddin
- Centre national de référence du paludisme, hôpital Bichat, 75018 Paris, France
| | - M Le Bouar
- Service de parasitologie-mycologie, CHU de Toulouse, 31300 Toulouse, France
| | - A Berry
- Service de parasitologie-mycologie, CHU de Toulouse, 31300 Toulouse, France
| | - O Fenneteau
- Service d'hématologie biologique, CHU Robert-Debré, AP-HP, 75018 Paris, France
| | - P Gillet
- Department of clinical sciences, institute of tropical medicine, 2000 Anvers, Belgium
| | - N Godineau
- Service de parasitologie, centre hospitalier Delafontaine, 93200 Saint-Denis, France
| | - E Candolfi
- Laboratoire de parasitologie, institut de parasitologie et de pathologie tropicale, hôpitaux civils de Strasbourg, CHU, 67000 Strasbourg, France
| | - S Houzé
- Centre national de référence du paludisme, hôpital Bichat, 75018 Paris, France; Service de parasitologie, hôpital Bichat, AP-HP, 75018 Paris, France.
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Sitali L, Miller JM, Mwenda MC, Bridges DJ, Hawela MB, Hamainza B, Chizema-Kawesha E, Eisele TP, Chipeta J, Lindtjørn B. Distribution of Plasmodium species and assessment of performance of diagnostic tools used during a malaria survey in Southern and Western Provinces of Zambia. Malar J 2019; 18:130. [PMID: 30971231 PMCID: PMC6458729 DOI: 10.1186/s12936-019-2766-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 04/04/2019] [Indexed: 11/10/2022] Open
Abstract
Background Zambia continues to make strides in reducing malaria burden through the use of proven malaria interventions and has recently pledged to eliminate malaria by 2021. Case management services have been scaled up at community level with rapid diagnostic tests (RDTs) providing antigen-based detection of falciparum malaria only. Key to national malaria elimination goals is the ability to identify, treat and eliminate all Plasmodium species. This study sought to determine the distribution of non-falciparum malaria and assess the performance of diagnostic tests for Plasmodium falciparum in Western and Southern Provinces of Zambia, two provinces planned for early malaria elimination. Methods A sub-set of individuals’ data and samples from a cross-sectional household survey, conducted during peak malaria transmission season in April and May 2017, was used. The survey collected socio-demographic information on household members and coverage of malaria interventions. Malaria testing was done on respondents of all ages using blood smears and RDTs while dried blood spots were collected on filter papers for analysis using photo-induced electron transfer polymerase chain reaction (PET-PCR). Slides were stained using Giemsa stain and examined by microscopy for malaria parasites. Results From the 1567 individuals included, the overall prevalence of malaria was 19.4% (CI 17.5–21.4) by PCR, 19.3% (CI 17.4–21.4) by RDT and 12.9% (CI 11.3–14.7) by microscopy. Using PET-PCR as the gold standard, RDTs showed a sensitivity of 75.7% (CI 70.4–80.4) and specificity of 94.2% (CI 92.8–95.4). The positive predictive value (PPV) was 75.9% (CI 70.7–80.6) and negative predictive value (NPV) was 94.1% (CI 92.1–95.4). In contrast, microscopy for sensitivity, specificity, PPV, and NPV values were 56.9% (CI 51.1–62.5), 97.7% (CI 96.7–98.5), 85.6% (CI 80.0–90.2), 90.4% (CI 88.7–91.9), respectively. Non-falciparum infections were found only in Western Province, where 11.6% of P. falciparum infections were co-infections with Plasmodium ovale or Plasmodium malariae. Conclusion From the sub-set of survey data analysed, non-falciparum species are present and occurred as mixed infections. As expected, PET-PCR was slightly more sensitive than both malaria RDTs and microscopy to detecting malaria infections.
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Affiliation(s)
- Lungowe Sitali
- Centre for International Health, Faculty of Medicine, University of Bergen, Bergen, Norway. .,Department of Biomedical Science, School of Health Sciences, University of Zambia, Lusaka, Zambia. .,School of Medicine and University Teaching Hospital Malaria Research Unit (SMUTH-MRU), Lusaka, Zambia.
| | - John M Miller
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), National Malaria Elimination Centre, Ministry of Health, Chainama Grounds, Lusaka, Zambia
| | - Mulenga C Mwenda
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), National Malaria Elimination Centre, Ministry of Health, Chainama Grounds, Lusaka, Zambia
| | - Daniel J Bridges
- PATH Malaria Control and Elimination Partnership in Africa (MACEPA), National Malaria Elimination Centre, Ministry of Health, Chainama Grounds, Lusaka, Zambia
| | - Moonga B Hawela
- National Malaria Elimination Centre, Ministry of Health, Chainama Hospital and College Grounds, Lusaka, Zambia
| | - Busiku Hamainza
- National Malaria Elimination Centre, Ministry of Health, Chainama Hospital and College Grounds, Lusaka, Zambia
| | - Elizabeth Chizema-Kawesha
- National Malaria Elimination Centre, Ministry of Health, Chainama Hospital and College Grounds, Lusaka, Zambia
| | - Thomas P Eisele
- Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA, USA.,Center for Applied Malaria Research and Evaluation, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA, USA
| | - James Chipeta
- School of Medicine and University Teaching Hospital Malaria Research Unit (SMUTH-MRU), Lusaka, Zambia.,Department of Paediatrics and Child Health, University of Zambia School of Medicine, Lusaka, Zambia
| | - Bernt Lindtjørn
- Centre for International Health, Faculty of Medicine, University of Bergen, Bergen, Norway
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Gao Y, Zhu Z, Xi X, Cao T, Wen W, Zhang X, Wang S. An aptamer-based hook-effect-recognizable three-line lateral flow biosensor for rapid detection of thrombin. Biosens Bioelectron 2019; 133:177-182. [PMID: 30928736 DOI: 10.1016/j.bios.2019.03.036] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Revised: 03/10/2019] [Accepted: 03/18/2019] [Indexed: 12/11/2022]
Abstract
In this paper, a three-line LFB was successfully developed by adding a thrombin line to a conventional two-line LFB for the detection of thrombin in a wide range of human serum. We introduced a thrombin line between the test line and the control line. The concentration of thrombin in the sample was quantitatively related to the signal formation on the three lines of the LFB. We can make use of signal on three lines to quantitative determinate the thrombin by data processing. The detection range of thrombin concentrations measured in 10 min was 1 nM to 100 μM and the LOD was 0.85 nM. Our approach paves way for rapid and sensitive thrombin detection and a superior device for testing in a wide range of physiological concentrations, which also can be used in other hook-effect-limited aptamers or antibodies based sandwich LFBs, and has a high accuracy even within the range of the hook-effect.
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Affiliation(s)
- Ya Gao
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Hubei University, Wuhan 430062, China; Ministry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, China
| | - Ziyu Zhu
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Hubei University, Wuhan 430062, China; Ministry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, China
| | - Xiaoxue Xi
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Hubei University, Wuhan 430062, China; Ministry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, China
| | - Tingwei Cao
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Hubei University, Wuhan 430062, China; Ministry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, China
| | - Wei Wen
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Hubei University, Wuhan 430062, China; Ministry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, China
| | - Xiuhua Zhang
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Hubei University, Wuhan 430062, China; Ministry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, China
| | - Shengfu Wang
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Hubei University, Wuhan 430062, China; Ministry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, China.
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Comparison of the Accuracy of Four Malaria Diagnostic Methods in a High Transmission Setting in Coastal Cameroon. J Parasitol Res 2019; 2019:1417967. [PMID: 30984417 PMCID: PMC6431520 DOI: 10.1155/2019/1417967] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 02/19/2019] [Accepted: 02/25/2019] [Indexed: 11/18/2022] Open
Abstract
Background Despite recommendation from the World Health Organization that all malaria suspected patients undergo a parasitological confirmation using rapid diagnostic test or light microscopy prior to treatment, health facilities in remote malaria endemic settings sometimes resort to presumptive diagnosis of malaria for clinical management for various reasons. Following observation of this practice, we undertook a cross-sectional study aimed at comparing presumptive diagnosis based on axillary temperature, SD Bioline™ rapid test, and light microscopy as strategies for malaria diagnosis in the coastal region of Mutengene in the South West of Cameroon with the overall goal of supporting improved malaria diagnosis at local levels. Methodology Venous blood from 320 participants was used to detect the presence of malaria parasite using SD Bioline™ mRDT and Giemsa stained microscopy or spotted on filter paper for PCR amplification of the 18s rRNA gene of Plasmodium sp following standard procedures. The axillary temperature of each participant was also measured. The sensitivity, specificity, and predictive values and their confidence intervals were determined for each of the methods with PCR as the reference. The area under the curve was used to estimate accuracy of diagnostic method and compared between test method using the X2 test with P<0.05 considered significant. Results The overall diagnostic sensitivities of presumptive diagnosis using axillary temperature, light microscopy, and SD Bioline™ were observed to be 74.30% (95%CI: 67.90-80.01), 94.86% (95%CI: 90.99-97.41), and 95.33% (95%CI: 91.57-97.74), respectively, and their respective diagnostic specificities were 53.77% (95%CI: 43.82-63.51), 94.34% (95%CI: 88.09-97.87), and 94.34%(95%CI: 88.09-97.89). SD Bioline™ had a diagnostic sensitivity of 91.80% [95%CI: 81.90-97.28] at a parasitaemia of less than 500 parasites/μl of blood but a sensitivity of 100% for parasite counts above 500 parasites/μl of blood. The predictive values of the positive test were highly comparable between light microscopy (90.09%, [95%CI: 83.61-94.18]) and SD Bioline™ mRDT (90.91%, [95%CI: 84.50-94.83]), P=0.98 with kappa values of 0.898 but lower for presumptive diagnosis (50.89%, [95%CI: 43.72-58.03]), P<0.0001, and kappa value of 0.277. Perfect agreement was observed between SD Bioline™ mRDT and light microscopy (Cohen kappa= 0.924). Conclusions The study showed that SD Bioline™ was as good as light microscopy in the diagnosis of malaria in remote areas of perennial transmission in South West Cameroon. This study equally revealed the limitations of presumptive diagnosis of malaria (as opposed to the use of RDTs or microscopy). Efforts should be made in such areas to promote parasitological confirmation of malaria using quality assured rapid tests or light microscopy for case management of malaria. The presence of nonnegligible levels of Plasmodium ovale in this study area indicate that treatment guidelines may require revision if same trend is proven in several other areas of same ecology.
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Simultaneous Quantification of Plasmodium Antigens and Host Factor C-Reactive Protein in Asymptomatic Individuals with Confirmed Malaria by Use of a Novel Multiplex Immunoassay. J Clin Microbiol 2019; 57:JCM.00948-18. [PMID: 30404944 PMCID: PMC6322473 DOI: 10.1128/jcm.00948-18] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 10/29/2018] [Indexed: 12/14/2022] Open
Abstract
Malaria rapid diagnostic tests (RDTs) primarily detect Plasmodium falciparum antigen histidine-rich protein 2 (HRP2) and the malaria-conserved antigen lactate dehydrogenase (LDH) for P. vivax and other malaria species. The performance of RDTs and their utility is dependent on circulating antigen concentration distributions in infected individuals in a population in which malaria is endemic and on the limit of detection of the RDT for the antigens. Malaria rapid diagnostic tests (RDTs) primarily detect Plasmodium falciparum antigen histidine-rich protein 2 (HRP2) and the malaria-conserved antigen lactate dehydrogenase (LDH) for P. vivax and other malaria species. The performance of RDTs and their utility is dependent on circulating antigen concentration distributions in infected individuals in a population in which malaria is endemic and on the limit of detection of the RDT for the antigens. A multiplexed immunoassay for the quantification of HRP2, P. vivax LDH, and all-malaria LDH (pan LDH) was developed to accurately measure circulating antigen concentration and antigen distribution in a population with endemic malaria. The assay also measures C-reactive protein (CRP) levels as an indicator of inflammation. Validation was conducted with clinical specimens from 397 asymptomatic donors from Myanmar and Uganda, confirmed by PCR for infection, and from participants in induced blood-stage malaria challenge studies. The assay lower limits of detection for HRP2, pan LDH, P. vivax LDH, and CRP were 0.2 pg/ml, 9.3 pg/ml, 1.5 pg/ml, and 26.6 ng/ml, respectively. At thresholds for HRP2, pan LDH, and P. vivax LDH of 2.3 pg/ml, 47.8 pg/ml, and 75.1 pg/ml, respectively, and a specificity ≥98.5%, the sensitivities for ultrasensitive PCR-confirmed infections were 93.4%, 84.9%, and 48.9%, respectively. Plasmodium LDH (pLDH) concentration, in contrast to that of HRP2, correlated closely with parasite density. CRP levels were moderately higher in P. falciparum infections with confirmed antigenemia versus those in clinical specimens with no antigen. The 4-plex array is a sensitive tool for quantifying diagnostic antigens in malaria infections and supporting the evaluation of new ultrasensitive RDTs.
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Steele C, Sinski A, Asibey J, Hardy-Dessources MD, Elana G, Brennan C, Odame I, Hoppe C, Geisberg M, Serrao E, Quinn CT. Point-of-care screening for sickle cell disease in low-resource settings: A multi-center evaluation of HemoTypeSC, a novel rapid test. Am J Hematol 2019; 94:39-45. [PMID: 30290004 DOI: 10.1002/ajh.25305] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 10/01/2018] [Indexed: 01/02/2023]
Abstract
Sickle cell disease (SCD) is a common, life-threatening genetic disorder that is best managed when diagnosed early by newborn screening. However, SCD is most prevalent in low-resource regions of the world where newborn screening is rare and diagnosis at the point-of-care is challenging. In many such regions, the majority of affected children die, undiagnosed, before the age of 5 years. A rapid and affordable point-of-care test for SCD is needed. The diagnostic accuracy of HemoTypeSC, a point-of-care immunoassay, for SCD was evaluated in individuals who had SCD, hemoglobin C disease, the related carrier (trait) states, or a normal hemoglobin phenotype. Children and adults participated in low-, medium- and high-resource environments (Ghana [n = 383], Martinique [n = 46], and USA [n = 158]). Paired blood specimens were obtained for HemoTypeSC and a reference diagnostic assay. HemoTypeSC testing was performed at the site of blood collection, and the reference test was performed in a laboratory at each site. In 587 participants, across all study sites, HemoTypeSC had an overall sensitivity of 99.5% and specificity of 99.9% across all hemoglobin phenotypes. The test had 100% sensitivity and specificity for sickle cell anemia. Sensitivity and specificity for detection of normal and trait states were >99%. HemoTypeSC is an inexpensive (<$2 per test), accurate, and rapid point-of-care test that can be used in resource-limited regions with a high prevalence of SCD to provide timely diagnosis and support newborn screening programs.
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Affiliation(s)
- Cindy Steele
- Operation International Kids; Southampton New York
- Children's Blood and Cancer Institute, Joseph M. Sanzari Children's Hospital; Hackensack New Jersey
| | - Annette Sinski
- Operation International Kids; Southampton New York
- Children's Blood and Cancer Institute, Joseph M. Sanzari Children's Hospital; Hackensack New Jersey
| | | | | | - Gisèle Elana
- Referral Center for Sickle Cell Disease; Department of Pediatrics, University Hospital of Martinique; Martinique
| | | | - Isaac Odame
- The Hospital for Sick Children, Department of Paediatrics; University of Toronto; Toronto Canada
| | - Carolyn Hoppe
- Department of Hematology-Oncology; UCSF Benioff Children's Hospital Oakland; Oakland California
| | | | - Erik Serrao
- Silver Lake Research Corporation; Azusa California
| | - Charles T. Quinn
- Division of Hematology; Cincinnati Children's Hospital Medical Center; Cincinnati Ohio
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Nkenfou CN, Hell VN, Georges NT, Ngoufack MN, Nkenfou CN, Kamgaing N, Ndjolo A. USAGE OF A RAPID DIAGNOSTIC TEST FOR MALARIA IN CHILDREN. Afr J Infect Dis 2018; 13:24-31. [PMID: 30596193 PMCID: PMC6305079 DOI: 10.21010/ajid.v13i1.3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 06/14/2017] [Accepted: 07/12/2017] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Malaria is still the primary cause of pediatric deaths. The efficient management of pediatric malaria requires its rapid and accurate diagnosis. To fulfill this requirement, rapid diagnostic tests have been developed, but their evaluation before commercialization is never exhaustive. The aim of this study was to evaluate the performance of a rapid diagnostic test (SD Bioline Malaria Antigen P.f/Pan) to diagnose malaria in children. MATERIALS AND METHODS Testing was conducted on children aged between 6 months and 15 years who were examined at the "Centre Mère Enfant (CME) of the "Chantal Biya" Foundation (FCB). as a result of fever. Enrollment took place from April to October 2014. All children presenting with fever were sampled (3ml of blood). These blood samples were tested for malaria using microscopy on a thick blood smear and by a rapid diagnostic test (RDT) SD Bioline Malariae Antigen P.f/Pan. RESULTS A total of 249 children were enrolled in this study. Malaria presence as determined by microscopy and by RDT was 30.9% and 58.2% respectively. The sensitivity, specificity, positive and negative predictive values compared to microscopy were: 75; 48.8; 39, and 81.6%. With these performances, the malaria SD Bioline rapid test presents lower values compared to WHO recommendations for rapid tests (sensitivity > 95%) in children. CONCLUSION SD Bioline Malaria Antigen P.f/Pan test should only be used in peripheral health structures that lack resources, and should be aided by clinical diagnosis.
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Affiliation(s)
- Céline Nguefeu Nkenfou
- Laboratory of Systems Biology, “Chantal Biya” International Reference Centre for Research on HIV/AIDS Prevention and Management (CBIRC), Yaounde, Cameroon
- Department of Biological Sciences, Higher Teacher Training College, University of Yaounde I, Yaounde, Cameroon
| | - Vestale Ngo Hell
- Catholic University, School of Health Sciences, Yaounde, Cameroon
| | | | - Marie Nicole Ngoufack
- Laboratory of Systems Biology, “Chantal Biya” International Reference Centre for Research on HIV/AIDS Prevention and Management (CBIRC), Yaounde, Cameroon
- Faculty of Sciences, University of Yaounde I, Yaounde, Cameroon
| | | | - Nelly Kamgaing
- Laboratory of Systems Biology, “Chantal Biya” International Reference Centre for Research on HIV/AIDS Prevention and Management (CBIRC), Yaounde, Cameroon
- Faculty of Medicine and Biomedical Sciences, University of Yaounde, Yaounde, Cameroon
| | - Alexis Ndjolo
- Laboratory of Systems Biology, “Chantal Biya” International Reference Centre for Research on HIV/AIDS Prevention and Management (CBIRC), Yaounde, Cameroon
- Faculty of Medicine and Biomedical Sciences, University of Yaounde, Yaounde, Cameroon
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Mbah HA, Jegede FE, Abdulrahman SA, Oyeyi TI. Evaluation of standard diagnostic rapid test kits for malaria diagnosis among HIV patients in Kano, Nigeria. Afr J Lab Med 2018; 7:698. [PMID: 30568892 PMCID: PMC6295795 DOI: 10.4102/ajlm.v7i1.698] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 08/13/2018] [Indexed: 12/03/2022] Open
Abstract
Background Malaria diagnosis among HIV-positive patients is uncommon in Nigeria despite the high burden of both diseases. Objectives We evaluated the performance of a malaria rapid diagnostic test (MRDT) against blood smear microscopy (BSM) among HIV-positive patients in relation to anti-retroviral treatment (ART) status, CD4+ count, fever, cotrimoxazole prophylaxis and malaria density count. Method A cross-sectional study involving 1521 consenting randomly selected HIV-positive adults attending two ART clinics in Kano, Nigeria, between June 2015 and May 2016. Venous blood samples were collected for testing with MRDT, BSM, and CD4+ T cells count by cytometry. Biodata and other clinical details were extracted from patient folders into an Excel file, cleaned, validated, and exported for analysis into SPSS version 23.0. Sensitivity, specificity, predictive values of MRDT were compared with BSM with a 95% confidence interval. Results Malaria parasites were detected in 25.4% of enrollees by BSM and 16.4% by MRDT. Overall sensitivity of MRDT was 58% and specificity was 97%. Cotrimoxazole prophylaxis and fever status did not affect MRDT sensitivity and specificity. Unexpectedly, the sensitivity was highest at parasite density count of less than 500 cells/µL. At CD4+ T cells count over 500 cells/µL the sensitivity was higher (62.4%) compared to 56% at less than 500 cells/µL. In the non-ART group sensitivity was higher (65%) compared to those on ART (56%) but the specificity was similar. All differences were significant for all variables (p < 0.05). Conclusion Although the MRDT specificity was good, the sensitivity was poor, requiring further evaluation for use in malaria diagnosis among HIV-malaria co-infected persons in these settings.
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Affiliation(s)
- Henry A Mbah
- LabTrail Global LLC, Smyrna, Delaware, United States
| | - Feyisayo E Jegede
- Biological Science Department, Bayero University Kano, Gwarzo Road Kano, Nigeria.,Family Health International-360, Garki,Federal Capital Territory, Abuja, Nigeria
| | | | - Tinuade I Oyeyi
- Biological Science Department, Bayero University Kano, Gwarzo Road Kano, Nigeria
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Orish VN, De-Gaulle VF, Sanyaolu AO. Interpreting rapid diagnostic test (RDT) for Plasmodium falciparum. BMC Res Notes 2018; 11:850. [PMID: 30509313 PMCID: PMC6278119 DOI: 10.1186/s13104-018-3967-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 11/29/2018] [Indexed: 12/21/2022] Open
Abstract
Objective Rapid diagnostic tests have been of tremendous help in malaria control in endemic areas, helping in diagnosis and treatment of malaria cases. It is heavily relied upon in many endemic areas where microscopy cannot be obtained. However, caution should be taken in the interpretation of its result in clinical setting due to its limitations and inherent weakness. This paper seeks to present the varying malaria RDT test results, the possible interpretations and explanation of these results common in endemic regions. Published works on malaria RDT studies were identified using the following search terms “malaria RDT in endemic areas”, “Plasmodium falciparum and bacterial coinfection” “Plasmodium falciparum RDT test results in children in endemic areas” in Google Scholar and PubMed. Results The review results show that RDT positive results in febrile patients can either be true or false positive. True positive, representing either a possible single infection of Plasmodium or a co-infection of bacteria and P. falciparum. False RDT negative results can be seen in febrile patient with P. falciparum infection in prozone effect, Histidine rich protein 2 (HRP2) gene deletion and faulty RDT kits. Hence, a scale up of laboratory facilities especially expert microscopy and other diagnostic tools is imperative.
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Affiliation(s)
- Verner N Orish
- Department of Microbiology and Immunology, School of Medicine, University of Health and Allied Sciences, Ho, Volta Region, Ghana
| | - Virtue F De-Gaulle
- Department of Social and Behavioural Sciences, School of Public Health, College of Health Sciences, University of Ghana, Accra, P. O. Box LG 13, Legon, Ghana.
| | - Adekunle O Sanyaolu
- Department of Medical Microbiology and Parasitology, College of Medicine of the University of Lagos, Idi-araba, Lagos, Nigeria
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Vernelen K, Barbé B, Gillet P, Van Esbroeck M, China B, Jacobs J. Photo-based External Quality Assessment of Malaria rapid diagnostic tests in a non-endemic setting. PLoS One 2018; 13:e0201622. [PMID: 30169508 PMCID: PMC6118386 DOI: 10.1371/journal.pone.0201622] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 07/18/2018] [Indexed: 11/20/2022] Open
Abstract
Introduction In non-endemic settings, expertise in malaria microscopy is limited and rapid diagnostic tests (RDTs) are an adjunct to malaria diagnosis. Aim We performed an External Quality Assessment (EQA) on reading and interpretation of malaria RDTs in a non-endemic setting. Methods Participants were medical laboratories in Belgium and the Grand Duchy of Luxembourg using malaria RDTs; they received (i) 10 high-resolution photographs presenting test line combinations of RDTs with interpretations listed in a multiple choice format and (ii) a questionnaire about their practices of malaria diagnosis. Results Among 135 subscribing laboratories, 134 (99.3%) used 139 RDT products (11 different products from 8 brands). After exclusion of the results of one laboratory, analysis was done for 133 laboratories using 137 RDT products. Scores of 10/10, 9/10 and 8/10 were achieved for 58.4%, 13.1% and 8.0% of 137 RDT products respectively. For three-band P. falciparum–pan-Plasmodium RDTs (113 (82.5%) products, 6 brands), most frequent errors were (1) disregarding faint test lines (18.6%), (2) reporting invalid instead of P. falciparum (16.8%) and (3) reporting “Plasmodium spp., no further differentiation possible” without mentioning the presence or absence of P. falciparum (11.5%). For four-band RDTs (21 (15.3%) products, 1 brand), errors were (4) disregarding faint P. vivax test lines (47.6%) and (5) reporting “Plasmodium spp., no further differentiation possible” without mentioning the presence of P. falciparum and P. vivax (28.6%). Instructions for use (IFU) of only 4 out of 10 RDT products mentioned to interpret faint-intensity test lines as positive (conducive to errors 1 and 4) and IFU of 2 products displayed incorrect information (conducive to errors 2 and 5). Outside of office hours, 36.1% of participants relied on RDTs as the initial diagnostic test; 13.9% did not perform microscopic confirmation. Conclusion Reading and interpretation of malaria RDTs was satisfactory, but errors were embedded in the instructions for use of the products. Relying on RDTs alone for malaria diagnosis (about one third of participants) is not a recommended practice.
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Affiliation(s)
- Kris Vernelen
- Quality of Medical Laboratories, Institute of Public Health, Sciensano, Brussels, Belgium
- * E-mail:
| | | | | | | | - Bernard China
- Quality of Medical Laboratories, Institute of Public Health, Sciensano, Brussels, Belgium
| | - Jan Jacobs
- Institute of Tropical Medicine, Antwerp, Belgium
- KU Leuven, Department of Microbiology and Immunology, Leuven, Belgium
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Peeters M, Chung P, Lin H, Mortelmans K, Phe C, San C, Kuijpers LMF, Teav S, Phe T, Jacobs J. Diagnostic accuracy of the InBiOS AMD rapid diagnostic test for the detection of Burkholderia pseudomallei antigen in grown blood culture broth. Eur J Clin Microbiol Infect Dis 2018; 37:1169-1177. [PMID: 29594800 PMCID: PMC5948296 DOI: 10.1007/s10096-018-3237-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 03/19/2018] [Indexed: 01/18/2023]
Abstract
To assess the diagnostic and operational performance of the InBiOS AMD rapid diagnostic test (RDT) (Seattle, USA) for the detection of B. pseudomallei in grown blood culture broth. The InBiOS RDT is a lateral flow immunoassay in a strip format detecting B. pseudomallei capsular polysaccharide in culture fluids, marketed for research only. Broth of blood culture bottles (BacT/Alert, bioMérieux, Marcy L’Etoile, France) sampled in adult patients at the Sihanouk Hospital Center of HOPE, Phnom Penh, Cambodia, during 2010–2017 and stored at − 80 °C was tested. They included samples grown with B. pseudomallei (n = 114), samples with no growth (n = 12), and samples with growth of other pathogens (n = 139, among which Burkholderia cepacia (n = 5)). Diagnostic sensitivity and specificity were 96.5% [95% confidence interval (CI): 91.3–98.6%] and 100% [CI: 97.5–100%] respectively. Background clearance and line intensities were good and very good. The RDT’s test strip, not housed in a cassette, caused difficulties in manipulation and biosafety. The centrifugation step prescribed by the procedure challenged biosafety, but processing of 19 B. pseudomallei samples without centrifugation showed similar results for line intensity and background clearance, compared to centrifugation. The InBiOS RDT showed excellent accuracy for detection of B. pseudomallei in grown blood culture broth. Provided operational adaptations such as cassette housing, it has the potential to reduce time to diagnosis of melioidosis.
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Affiliation(s)
- Marjan Peeters
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium.
| | - Panha Chung
- Sihanouk Hospital Center of HOPE, Phnom Penh, Cambodia
| | - Hua Lin
- SRI International, Menlo Park, CA, USA
| | | | - Chhundy Phe
- Sihanouk Hospital Center of HOPE, Phnom Penh, Cambodia
| | - Chentha San
- Sihanouk Hospital Center of HOPE, Phnom Penh, Cambodia
| | - Laura Maria Francisca Kuijpers
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
- Department of Microbiology and Immunology, KU Leuven, Leuven, Belgium
| | - Syna Teav
- Sihanouk Hospital Center of HOPE, Phnom Penh, Cambodia
| | - Thong Phe
- Sihanouk Hospital Center of HOPE, Phnom Penh, Cambodia
| | - Jan Jacobs
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
- Department of Microbiology and Immunology, KU Leuven, Leuven, Belgium
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Falade CO, Ajayi IO, Nsungwa-Sabiiti J, Siribié M, Diarra A, Sermé L, Afonne C, Yusuf OB, Gansane Z, Jegede AS, Singlovic J, Gomes M. Malaria Rapid Diagnostic Tests and Malaria Microscopy for Guiding Malaria Treatment of Uncomplicated Fevers in Nigeria and Prereferral Cases in 3 African Countries. Clin Infect Dis 2018; 63:S290-S297. [PMID: 27941107 PMCID: PMC5146700 DOI: 10.1093/cid/ciw628] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Background. The World Health Organization recommends that malaria treatment be based on demonstration of the infecting Plasmodium parasite specie. Malaria rapid diagnostic tests (RDTs) are recommended at community points of care because they are accurate and rapid. We report on parasitological results in a malaria study in selected rural communities in 3 African countries. Methods. In Nigeria, community health workers (CHWs) performed RDTs (SD-Bioline) and thick blood smears on all children suspected to have malaria. Malaria RDT-positive children able to swallow received artemisinin-based combination therapy (Coartem). In all countries, children unable to take oral drugs received prereferral rectal artesunate irrespective of RDT result and were referred to the nearest health facility. Thick blood smears and RDTs were usually taken at hospital admission. In Nigeria and Burkina Faso, RDT cassettes and blood smears were re-read by an experienced investigator at study end. Results. Trained CHWs enrolled 2148 children in Nigeria. Complete parasitological data of 1860 (86.6%) enrollees were analyzed. The mean age of enrollees was 30.4 ± 15.7 months. The prevalence of malaria parasitemia in the study population was 77.8% (1447/1860), 77.6% (1439/1855), and 54.1% (862/1593) by RDT performed by CHWs vs an expert clinical research assistant vs microscopy (gold standard), respectively. Geometric mean parasite density was 6946/µL (range, 40–436 450/µL). There were 49 cases of RDT false-negative results with a parasite density range of 40–54 059/µL. False-negative RDT results with high parasitemia could be due to non-falciparum infection or result from a prozone effect. Sensitivity and specificity of SD-Bioline RDT results as read by CHWs were 94.3% and 41.6%, respectively, while the negative and positive predictive values were 86.1% and 65.6%, respectively. The level of agreement in RDT reading by the CHWs and experienced research staff was 86.04% and κ statistic of 0.60. The malaria parasite positivity rate by RDT and microscopy among children with danger signs in the 3 countries was 67.9% and 41.8%, respectively. Conclusions. RDTs are useful in guiding malaria management and were successfully used for diagnosis by trained CHWs. However, false-negative RDT results were identified and can undermine confidence in results and control efforts.
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Affiliation(s)
| | - IkeOluwapo O Ajayi
- Department of Epidemiology and Medical Statistics, College of Medicine, University of Ibadan, Nigeria
| | | | | | - Amidou Diarra
- Groupe de Recherche Action en Santé, Ouagadougou, Burkina Faso
| | - Luc Sermé
- Groupe de Recherche Action en Santé, Ouagadougou, Burkina Faso
| | - Chinenye Afonne
- Epidemiology and Biostatistics Research Unit, Institute of Advanced Medical Research and Training, College of Medicine
| | - Oyindamola B Yusuf
- Department of Epidemiology and Medical Statistics, College of Medicine, University of Ibadan, Nigeria
| | - Zakaria Gansane
- Groupe de Recherche Action en Santé, Ouagadougou, Burkina Faso
| | - Ayodele S Jegede
- Department of Sociology, Faculty of Social Sciences, University of Ibadan, Nigeria
| | - Jan Singlovic
- UNICEF/UNDP/World Bank/WHO/Special Programme for Research & Training in Tropical Diseases, World Health Organization, Geneva, Switzerland
| | - Melba Gomes
- UNICEF/UNDP/World Bank/WHO/Special Programme for Research & Training in Tropical Diseases, World Health Organization, Geneva, Switzerland
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Iwuafor AA, Ita OI, Ogban GI, Udoh UA, Amajor CA. Evaluation of Diagnostic Accuracy of Rapid Diagnostic Test for Malaria Diagnosis among Febrile Children in Calabar, Nigeria. Niger Med J 2018; 59:64-69. [PMID: 31423044 PMCID: PMC6668302 DOI: 10.4103/nmj.nmj_165_18] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Background The WHO recommends that all cases of suspected malaria should undergo parasitological test. Currently, the parasitological test comprises the rapid diagnostic test (RDT) or the microscopy. The performance of RDT in relation to microscopy is yet to be fully comprehended. Objectives This study evaluated the diagnostic accuracy of RDT as against the diagnosis provided by microscopy in detecting malaria parasites among febrile under-5 children. Design The study was a cross-sectional hospital-based design. Materials and Methods Capillary blood samples were collected from 167 children who came to the hospital with a history of fever over a period of 6 months. The Paracheck-Pf RDT kit was used and its performance was compared with the gold standard, microscopy using thick film. Results The prevalence of malaria infection was 41.9%. On comparing RDT with microscopy (microscopy assumed to be 100% sensitive and specific), RDT had a sensitivity of 51.4% and a specificity of 73.2%. The false-positive rate was 26.8% whereas the false-negative rate was 48.6%. The positive predictive value was 58.1% whereas the negative predictive value (NPV) was 67.6%. The RDT also had a positive likelihood ratio (LR) of 1.92 and a negative LR of 0.67. The RDT test accuracy was 64.1%. Conclusion Malaria prevalence among febrile children was found to be high. The findings also suggest that inconsistencies in the performance of RDT kits may arise from many extraneous factors, and as such, they should not be used as a stand-alone test kit except a prior batch/lot validation test was carried on them.
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Affiliation(s)
- Anthony Achizie Iwuafor
- Department of Medical Microbiology and Parasitology, Faculty of Medicine, College of Medical Sciences, University of Calabar, Calabar, Cross River State, Nigeria
| | - Okokon Ita Ita
- Department of Medical Microbiology and Parasitology, Faculty of Medicine, College of Medical Sciences, University of Calabar, Calabar, Cross River State, Nigeria
| | - Godwin Ibitham Ogban
- Department of Medical Microbiology and Parasitology, Faculty of Medicine, College of Medical Sciences, University of Calabar, Calabar, Cross River State, Nigeria
| | - Ubong A Udoh
- Department of Medical Microbiology and Parasitology, Faculty of Medicine, College of Medical Sciences, University of Calabar, Calabar, Cross River State, Nigeria
| | - Chimereze Anthony Amajor
- Department of Paediatrics, Faculty of Medicine, College of Medical Sciences, University of Calabar, Calabar, Cross River State, Nigeria
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Godakhindi VS, Kang P, Serre M, Revuru NA, Zou JM, Roner MR, Levitz R, Kahn JS, Randrianalisoa J, Qin Z. Tuning the Gold Nanoparticle Colorimetric Assay by Nanoparticle Size, Concentration, and Size Combinations for Oligonucleotide Detection. ACS Sens 2017; 2:1627-1636. [PMID: 28994578 DOI: 10.1021/acssensors.7b00482] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Gold nanoparticle (GNP)-based aggregation assay is simple, fast, and employs a colorimetric detection method. Although previous studies have reported using GNP-based colorimetric assay to detect biological and chemical targets, a mechanistic and quantitative understanding of the assay and effects of GNP parameters on the assay performance is lacking. In this work, we investigated this important aspect of the GNP aggregation assay including effects of GNP concentration and size on the assay performance to detect malarial DNA. Our findings lead us to propose three major competing factors that determine the final assay performance including the nanoparticle aggregation rate, plasmonic coupling strength, and background signal. First, increasing nanoparticle size reduces the Brownian motion and thus aggregation rate, but significantly increases plasmonic coupling strength. We found that larger GNP leads to stronger signal and improved limit of detection (LOD), suggesting a dominating effect of plasmonic coupling strength. Second, higher nanoparticle concentration increases the probability of nanoparticle interactions and thus aggregation rate, but also increases the background extinction signal. We observed that higher GNP concentration leads to stronger signal at high target concentrations due to higher aggregation rate. However, the fact the optimal LOD was found at intermediate GNP concentrations suggests a balance of two competing mechanisms between aggregation rate and signal/background ratio. In summary, our work provides new guidelines to design GNP aggregation-based POC devices to meet the signal and sensitivity needs for infectious disease diagnosis and other applications.
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Affiliation(s)
| | | | - Maud Serre
- Ecole
Nationale Supérieure d’Ingénieurs de Reims (ESIReims), University of Reims Champagne - Ardenne, 3 Espl. Roland Garros, 51100 Reims, France
| | | | | | - Michael R. Roner
- Department
of Biology, University of Texas at Arlington, 701 South Nedderman Drive, Arlington, Texas 76019, United States
| | | | | | - Jaona Randrianalisoa
- Groupe
de Recherche en Sciences pour l’Ingénieur (GRESPI) -
EA 4694, University of Reims Champagne - Ardenne, 51687 Reims Cedex 2, France
| | - Zhenpeng Qin
- Children’s Medical Center, 1935
Medical District Drive, Dallas, Texas 75235, United States
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De Koninck AS, Cnops L, Hofmans M, Jacobs J, Van den Bossche D, Philippé J. Diagnostic performance of the loop-mediated isothermal amplification (LAMP) based illumigene ® malaria assay in a non-endemic region. Malar J 2017; 16:418. [PMID: 29041927 PMCID: PMC5645927 DOI: 10.1186/s12936-017-2065-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 10/13/2017] [Indexed: 01/09/2023] Open
Abstract
Background Light microscopy and antigen-based rapid diagnostic tests are the primary diagnostic tools for detecting malaria, although being labour-intensive and frequently challenged by lack of personnel’s experience and low levels of parasite density. The latter being especially important in non-endemic settings. Novel molecular techniques aim to overcome this drawback. The objective of this study was to assess the diagnostic performance of the illumigene malaria assay® (Meridian Bioscience) compared to microscopy, RDT and real-time PCR. This loop-mediated isothermal amplification (LAMP) assay is a qualitative in vitro diagnostic test for the direct detection of Plasmodium spp. DNA in human venous whole blood samples. Methods The illumigene assay was assessed on a retrospective panel of stored blood samples (n = 103) from returned travellers and external quality control samples (n = 12). Additionally the assay was prospectively assessed on 30 fresh routine samples with a request for malaria diagnosis. The illumigene assay was compared to microscopy, RDT and Plasmodium species specific real-time PCR. Results In the retrospective evaluation, the illumigene assay showed 100% agreement with the real-time PCR, RDT and microscopy yielding a sensitivity and specificity of 100% (95% CI 95.1–100% and 89.7–100%, respectively). Seven samples from patients recently treated for Plasmodium falciparum infection that were RDT positive and microscopy negative yielded positive test results. The performance of the illumigene assay equals that of microscopy combined with RDT in the prospective panel with three false negative RDT results and one false negative microscopy result. Excellent concordance with PCR was observed. The limit of detection of the assay approached 0.5 parasites/µL for both P. falciparum and Plasmodium vivax. Conclusion In non-endemic regions where the diagnostic process for malaria infections is questioned by lack of experience and low levels of parasite densities, the illumigene assay can be of value. Due to its high sensitivity, the LAMP assay may be considered as primary diagnostic test. The results of this study indicate that negative screen results do not need further confirmation. However, before implementation, this approach needs to be confirmed in larger, prospective studies. A shortcoming of this assay is that no species identification nor determination of parasite density are possible.
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Affiliation(s)
- Anne-Sophie De Koninck
- Department of Laboratory Medicine, Ghent University Hospital (GUH), De Pintelaan 185, 9000, Ghent, Belgium
| | - Lieselotte Cnops
- Institute of Tropical Medicine (ITM) Antwerp, Nationalestraat 155, 2000, Antwerp, Belgium
| | - Mattias Hofmans
- Department of Laboratory Medicine, Ghent University Hospital (GUH), De Pintelaan 185, 9000, Ghent, Belgium
| | - Jan Jacobs
- Institute of Tropical Medicine (ITM) Antwerp, Nationalestraat 155, 2000, Antwerp, Belgium
| | - Dorien Van den Bossche
- Institute of Tropical Medicine (ITM) Antwerp, Nationalestraat 155, 2000, Antwerp, Belgium
| | - Jan Philippé
- Department of Laboratory Medicine, Ghent University Hospital (GUH), De Pintelaan 185, 9000, Ghent, Belgium.
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Ratanabanangkoon K, Simsiriwong P, Pruksaphon K, Tan KY, Eursakun S, Tan CH, Chantrathonkul B, Wongwadhunyoo W, Youngchim S, Tan NH. A novel in vitro potency assay of antisera against Thai Naja kaouthia based on nicotinic acetylcholine receptor binding. Sci Rep 2017; 7:8545. [PMID: 28819275 PMCID: PMC5561211 DOI: 10.1038/s41598-017-08962-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 07/17/2017] [Indexed: 11/30/2022] Open
Abstract
Snake envenomation is an important medical problem. One of the hurdles in antivenom development is the in vivo assay of antivenom potency which is expensive, gives variable results and kills many animals. We report a novel in vitro assay involving the specific binding of the postsynaptic neurotoxins (PSNTs) of elapid snakes with purified Torpedo californica nicotinic acetylcholine receptor (nAChR). The potency of an antivenom is determined by its antibody ability to bind and neutralize the PSNT, thus preventing it from binding to nAChR. The PSNT of Naja kaouthia (NK3) was immobilized on microtiter wells and nAChR was added to bind with it. The in vitro IC50 of N. kaouthia venom that inhibited 50% of nAChR binding to the immobilized NK3 was determined. Varying concentrations of antisera against N. kaouthia were separately pre-incubated with 5xIC50 of N. kaouthia venom. The remaining free NK3 were incubated with nAChR before adding to the NK3 coated plates. The in vitro and in vivo median effective ratio, ER50s of 12 batches of antisera showed correlation (R 2) of 0.9809 (p < 0.0001). This in vitro assay should be applicable to antisera against other elapid venoms and should reduce the use of live animals and accelerate development of life-saving antivenoms.
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Affiliation(s)
- Kavi Ratanabanangkoon
- Laboratory of Immunology, Chulabhorn Research Institute, Bangkok, Thailand
- Chulabhorn Graduate Institute, Bangkok, 10210 Thailand
- Department of Microbiology, Faculty of Science, Mahidol University, Rama 6 Road, Bangkok, 10400 Thailand
| | | | - Kritsada Pruksaphon
- Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Kae Yi Tan
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, 50603 Malaysia
| | - Sukanya Eursakun
- Laboratory of Immunology, Chulabhorn Research Institute, Bangkok, Thailand
| | - Choo Hock Tan
- Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, 50603 Malaysia
| | | | | | - Sirida Youngchim
- Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Nget Hong Tan
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, 50603 Malaysia
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Roy RD, Rosenmund C, Stefan MI. Cooperative binding mitigates the high-dose hook effect. BMC SYSTEMS BIOLOGY 2017; 11:74. [PMID: 28807050 PMCID: PMC5556679 DOI: 10.1186/s12918-017-0447-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 07/19/2017] [Indexed: 11/29/2022]
Abstract
Background The high-dose hook effect (also called prozone effect) refers to the observation that if a multivalent protein acts as a linker between two parts of a protein complex, then increasing the amount of linker protein in the mixture does not always increase the amount of fully formed complex. On the contrary, at a high enough concentration range the amount of fully formed complex actually decreases. It has been observed that allosterically regulated proteins seem less susceptible to this effect. The aim of this study was two-fold: First, to investigate the mathematical basis of how allostery mitigates the prozone effect. And second, to explore the consequences of allostery and the high-dose hook effect using the example of calmodulin, a calcium-sensing protein that regulates the switch between long-term potentiation and long-term depression in neurons. Results We use a combinatorial model of a “perfect linker protein” (with infinite binding affinity) to mathematically describe the hook effect and its behaviour under allosteric conditions. We show that allosteric regulation does indeed mitigate the high-dose hook effect. We then turn to calmodulin as a real-life example of an allosteric protein. Using kinetic simulations, we show that calmodulin is indeed subject to a hook effect. We also show that this effect is stronger in the presence of the allosteric activator Ca 2+/calmodulin-dependent kinase II (CaMKII), because it reduces the overall cooperativity of the calcium-calmodulin system. It follows that, surprisingly, there are conditions where increased amounts of allosteric activator actually decrease the activity of a protein. Conclusions We show that cooperative binding can indeed act as a protective mechanism against the hook effect. This will have implications in vivo where the extent of cooperativity of a protein can be modulated, for instance, by allosteric activators or inhibitors. This can result in counterintuitive effects of decreased activity with increased concentrations of both the allosteric protein itself and its allosteric activators. Electronic supplementary material The online version of this article (doi:10.1186/s12918-017-0447-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ranjita Dutta Roy
- Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden.,NWFZ, Charité Crossover, Charite Universitätsmedizin, Berlin, Germany
| | | | - Melanie I Stefan
- Department of Neurobiology, Harvard Medical School, Boston, USA. .,Babraham Institute, Cambridge, UK. .,Centre for Integrative Physiology, University of Edinburgh, Edinburgh, UK.
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Boyce MR, O'Meara WP. Use of malaria RDTs in various health contexts across sub-Saharan Africa: a systematic review. BMC Public Health 2017; 17:470. [PMID: 28521798 PMCID: PMC5437623 DOI: 10.1186/s12889-017-4398-1] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 05/08/2017] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND The World Health Organization recommends parasitological confirmation of malaria prior to treatment. Malaria rapid diagnostic tests (RDTs) represent one diagnostic method that is used in a variety of contexts to overcome limitations of other diagnostic techniques. Malaria RDTs increase the availability and feasibility of accurate diagnosis and may result in improved quality of care. Though RDTs are used in a variety of contexts, no studies have compared how well or effectively RDTs are used across these contexts. This review assesses the diagnostic use of RDTs in four different contexts: health facilities, the community, drug shops and schools. METHODS A comprehensive search of the Pubmed database was conducted to evaluate RDT execution, test accuracy, or adherence to test results in sub-Saharan Africa. Original RDT and Plasmodium falciparum focused studies conducted in formal health care facilities, drug shops, schools, or by CHWs between the year 2000 and December 2016 were included. Studies were excluded if they were conducted exclusively in a research laboratory setting, where staff from the study team conducted RDTs, or in settings outside of sub-Saharan Africa. RESULTS The literature search identified 757 reports. A total of 52 studies were included in the analysis. Overall, RDTs were performed safely and effectively by community health workers provided they receive proper training. Analogous information was largely absent for formal health care workers. Tests were generally accurate across contexts, except for in drug shops where lower specificities were observed. Adherence to RDT results was higher among drug shop vendors and community health workers, while adherence was more variable among formal health care workers, most notably with negative test results. CONCLUSIONS Malaria RDTs are generally used well, though compliance with test results is variable - especially in the formal health care sector. If low adherence rates are extrapolated, thousands of patients may be incorrectly diagnosed and receive inappropriate treatment resulting in a low quality of care and unnecessary drug use. Multidisciplinary research should continue to explore determinants of good RDT use, and seek to better understand how to support and sustain the correct use of this diagnostic tool.
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Affiliation(s)
| | - Wendy P O'Meara
- Duke Global Health Institute, Durham, NC, USA.,School of Public Health, Moi University College of Health Sciences, Eldoret, Kenya
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