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Khedhiri M, Chaouch M, Ayouni K, Chouikha A, Gdoura M, Touzi H, Hogga N, Benkahla A, Fares W, Triki H. Development and evaluation of an easy to use real-time reverse-transcription loop-mediated isothermal amplification assay for clinical diagnosis of West Nile virus. J Clin Virol 2024; 170:105633. [PMID: 38103483 DOI: 10.1016/j.jcv.2023.105633] [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: 06/17/2023] [Revised: 11/09/2023] [Accepted: 12/06/2023] [Indexed: 12/19/2023]
Abstract
West Nile Virus (WNV) causes a serious public health concern in many countries around the world. Virus detection in pathological samples is a key component of WNV infection diagnostic, classically performed by real-time PCR. In outbreak situation, rapid detection of the virus, in peripheral laboratories or at point of care, is crucial to guide decision makers and for the establishment of adequate action plans to prevent virus dissemination. Here, we evaluate a Loop-mediated isothermal amplification (LAMP) tool for WNV detection. Amplifications were performed comparatively on extracted viral RNA and on crude samples using a classical thermal cycler and a portable device (pebble device). qRT-PCR was used as gold standard and two sets of urine samples (n = 62 and n = 74) were used to evaluate the retained amplification protocols and assess their sensitivity and specificity. RT-LAMP on RNA extracts and crude samples showed a sensitivity of 90 % and 87 %, respectively. The specificity was 100 % for extracts and 97 % for crude samples. Using the device, the RT-LAMP on extracted RNA was comparable to the gold standard results (100 % sensitivity and specificity) and it was a bit lower on crude samples (65 % sensitivity and 94 % specificity). These results show that RT-LAMP is an efficient technique to detect WNV. RT-LAMP provides a rapid, sensitive, high-throughput and portable tool for accurate WNV detection and has potentials to facilitate diagnostic and surveillance efforts both in the laboratory and in the field, especially in developing countries.
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Affiliation(s)
- Marwa Khedhiri
- Laboratory of Clinical Virology, WHO Reference Laboratory for Poliomyelitis and Measles in the Eastern Mediterranean Region, Pasteur Institute of Tunis, University Tunis El Manar (UTM), Tunis 1002, Tunisia; Research Laboratory: "Virus, Vector and Host" (LR20IPT02), Pasteur Institute of Tunis, Tunis 1002, Tunisia; Clinical Investigation Center (CIC), Pasteur Institute of Tunis, University of Tunis El Manar (UTM), Tunis 1002, Tunisia.
| | - Melek Chaouch
- Laboratory of Medical Parasitology, Biotechnology and Biomolecules (LR16IPT06), Pasteur Institute of Tunis, Tunis 1002, Tunisia; Laboratory of BioInformatics, BioMathematics and BioStatistics Laboratory (LR16IPT09), Pasteur Institute of Tunis, Tunis 1002, Tunisia
| | - Kaouther Ayouni
- Laboratory of Clinical Virology, WHO Reference Laboratory for Poliomyelitis and Measles in the Eastern Mediterranean Region, Pasteur Institute of Tunis, University Tunis El Manar (UTM), Tunis 1002, Tunisia; Research Laboratory: "Virus, Vector and Host" (LR20IPT02), Pasteur Institute of Tunis, Tunis 1002, Tunisia; Clinical Investigation Center (CIC), Pasteur Institute of Tunis, University of Tunis El Manar (UTM), Tunis 1002, Tunisia
| | - Anissa Chouikha
- Laboratory of Clinical Virology, WHO Reference Laboratory for Poliomyelitis and Measles in the Eastern Mediterranean Region, Pasteur Institute of Tunis, University Tunis El Manar (UTM), Tunis 1002, Tunisia; Research Laboratory: "Virus, Vector and Host" (LR20IPT02), Pasteur Institute of Tunis, Tunis 1002, Tunisia; Clinical Investigation Center (CIC), Pasteur Institute of Tunis, University of Tunis El Manar (UTM), Tunis 1002, Tunisia
| | - Mariem Gdoura
- Laboratory of Clinical Virology, WHO Reference Laboratory for Poliomyelitis and Measles in the Eastern Mediterranean Region, Pasteur Institute of Tunis, University Tunis El Manar (UTM), Tunis 1002, Tunisia; Research Laboratory: "Virus, Vector and Host" (LR20IPT02), Pasteur Institute of Tunis, Tunis 1002, Tunisia; Clinical Investigation Center (CIC), Pasteur Institute of Tunis, University of Tunis El Manar (UTM), Tunis 1002, Tunisia
| | - Henda Touzi
- Laboratory of Clinical Virology, WHO Reference Laboratory for Poliomyelitis and Measles in the Eastern Mediterranean Region, Pasteur Institute of Tunis, University Tunis El Manar (UTM), Tunis 1002, Tunisia; Research Laboratory: "Virus, Vector and Host" (LR20IPT02), Pasteur Institute of Tunis, Tunis 1002, Tunisia; Clinical Investigation Center (CIC), Pasteur Institute of Tunis, University of Tunis El Manar (UTM), Tunis 1002, Tunisia
| | - Nahed Hogga
- Laboratory of Clinical Virology, WHO Reference Laboratory for Poliomyelitis and Measles in the Eastern Mediterranean Region, Pasteur Institute of Tunis, University Tunis El Manar (UTM), Tunis 1002, Tunisia; Research Laboratory: "Virus, Vector and Host" (LR20IPT02), Pasteur Institute of Tunis, Tunis 1002, Tunisia; Clinical Investigation Center (CIC), Pasteur Institute of Tunis, University of Tunis El Manar (UTM), Tunis 1002, Tunisia
| | - Alia Benkahla
- Laboratory of Medical Parasitology, Biotechnology and Biomolecules (LR16IPT06), Pasteur Institute of Tunis, Tunis 1002, Tunisia
| | - Wasfi Fares
- Laboratory of Clinical Virology, WHO Reference Laboratory for Poliomyelitis and Measles in the Eastern Mediterranean Region, Pasteur Institute of Tunis, University Tunis El Manar (UTM), Tunis 1002, Tunisia; Research Laboratory: "Virus, Vector and Host" (LR20IPT02), Pasteur Institute of Tunis, Tunis 1002, Tunisia; Clinical Investigation Center (CIC), Pasteur Institute of Tunis, University of Tunis El Manar (UTM), Tunis 1002, Tunisia
| | - Henda Triki
- Laboratory of Clinical Virology, WHO Reference Laboratory for Poliomyelitis and Measles in the Eastern Mediterranean Region, Pasteur Institute of Tunis, University Tunis El Manar (UTM), Tunis 1002, Tunisia; Research Laboratory: "Virus, Vector and Host" (LR20IPT02), Pasteur Institute of Tunis, Tunis 1002, Tunisia; Clinical Investigation Center (CIC), Pasteur Institute of Tunis, University of Tunis El Manar (UTM), Tunis 1002, Tunisia
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Dias BDP, Barbosa CC, Ferreira CS, Mayra Soares Alves Dos Santos S, Arrieta OAP, Malta WC, Gomes MLMD, Alves E Silva M, Fonseca JDM, Borges LP, Silva BDM. Challenges in Direct Detection of Flaviviruses: A Review. Pathogens 2023; 12:pathogens12050643. [PMID: 37242313 DOI: 10.3390/pathogens12050643] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 04/18/2023] [Accepted: 04/20/2023] [Indexed: 05/28/2023] Open
Abstract
Arthropods transmit arboviruses via mosquito and tick bites to humans and other animals. The genus flavivirus, which causes diseases, sequelae, and thousands of deaths, mainly in developing and underdeveloped countries, is among the arboviruses of interest to public health. Given the importance of early and accurate diagnosis, this review analyzes the methods of direct detection of flaviviruses, such as reverse transcription loop-mediated isothermal amplification, microfluidics, localized surface plasmon resonance, and surface-enhanced Raman scattering, and presents the advantages, disadvantages, and detection limits identified in studies reported in the literature for each methodology. Among the different methods available, it is essential to balance four fundamental indicators to determine the ideal test: good sensitivity, high specificity, low false positive rate, and rapid results. Among the methods analyzed, reverse transcription loop-mediated isothermal amplification stands out, owing to result availability within a few minutes, with good sensitivity and specificity; in addition, it is the best-characterized methodology.
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Affiliation(s)
- Bruna de Paula Dias
- Department of Biological Sciences, Federal University of Ouro Preto, Ouro Preto 35400-000, Brazil
| | - Camila Cavadas Barbosa
- Department of Biological Sciences, Federal University of Ouro Preto, Ouro Preto 35400-000, Brazil
| | - Cyntia Silva Ferreira
- Department of Biological Sciences, Federal University of Ouro Preto, Ouro Preto 35400-000, Brazil
| | | | | | | | | | - Mariela Alves E Silva
- Department of Biological Sciences, Federal University of Ouro Preto, Ouro Preto 35400-000, Brazil
| | - Júlia de Matos Fonseca
- Department of Biological Sciences, Federal University of Ouro Preto, Ouro Preto 35400-000, Brazil
| | - Lysandro Pinto Borges
- Department of Pharmacy, Federal University of Sergipe, São Cristóvão 9100-000, Brazil
| | - Breno de Mello Silva
- Department of Biological Sciences, Federal University of Ouro Preto, Ouro Preto 35400-000, Brazil
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Febrer-Sendra B, Fernández-Soto P, García-Bernalt Diego J, Crego-Vicente B, Negredo A, Muñor-Bellido JL, Belhassen-García M, Sánchez-Seco MP, Muro A. A Novel RT-LAMP for the Detection of Different Genotypes of Crimean–Congo Haemorrhagic Fever Virus in Patients from Spain. Int J Mol Sci 2023; 24:ijms24076411. [PMID: 37047384 PMCID: PMC10094476 DOI: 10.3390/ijms24076411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 03/25/2023] [Accepted: 03/27/2023] [Indexed: 03/31/2023] Open
Abstract
Crimean–Congo haemorrhagic fever (CCHF) is a potentially lethal tick-borne viral disease with a wide distribution. In Spain, 12 human cases of CCHF have been confirmed, with four deaths. The diagnosis of CCHF is hampered by the nonspecific symptoms, the high genetic diversity of CCHFV, and the biosafety requirements to manage the virus. RT-qPCR and serological tests are used for diagnosis with limitations. Reverse-transcription loop-mediated isothermal amplification (RT-LAMP) could be an effective alternative in the diagnosis of the disease. However, none of the few RT-LAMP assays developed to date has detected different CCHFV genotypes. Here, we designed a RT-LAMP using a degenerate primer set to compensate for the variability of the CCHFV target sequence. RT-LAMP was performed in colorimetric and real-time tests on RT-qPCR-confirmed CCHF patient samples notified in Spain in 2020 and 2021. Urine from an inpatient was analysed by RT-LAMP for the first time and compared with RT-qPCR. The amplicons obtained by RT-qPCR were sequenced and African III and European V genotypes were identified. RT-LAMP amplified both genotypes and was more sensitive than RT-qPCR in urine samples. We have developed a novel, rapid, specific, and sensitive RT-LAMP test that allows the detection of different CCHFV genotypes in clinical samples. This pan-CCHFV RT-LAMP detected viral RNA for the first time in urine samples. It can be easily performed as a single-tube isothermal colorimetric method on a portable platform in real time and without the need for expensive equipment, thus bringing molecular diagnostics closer to rural or resource-poor areas, where CCHF usually occurs.
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Boora S, Khan A, Sharma V, Kaushik S, Mehta PK, Singh S, Kaushik S. RT-LAMP is a potential future molecular diagnostic tool for influenza A virus. Future Virol 2023. [DOI: 10.2217/fvl-2022-0136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2023]
Abstract
Aim: Influenza A virus (IAV) causes serious illness and is responsible for significant morbidity and mortality. To diagnose IAV infection in its early stages, a quick, sensitive, precise detection method is needed for effective clinical management. Materials & methods: In-house hydroxylnaphthol blue (HNB)-based RT-LAMP assay for early detection of IAV using the HA gene was compared with RT-PCR/multiplex-RT-PCR. Results: For the reference strains of IAV, (H1N1 (A/Texas/50/2012) and H3N2 (A/Malaysia/2089302/2009)) RT-LAMP and RT-PCR/M-RT-PCR exhibited a limit of detection (LOD) of 10 and 100 fg/ml, respectively. Conclusion: HNB-based RT-LAMP is a rapid, sensitive, cost-effective diagnostic tool, and could be a point-of-care test for IAV patients during outbreaks.
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Affiliation(s)
- Sanjit Boora
- Centre for Biotechnology, Maharshi Dayanand University, Rohtak, Haryana, 124001, India
| | - Anish Khan
- Centre for Biotechnology, Maharshi Dayanand University, Rohtak, Haryana, 124001, India
- Department of Biochemistry, Maharshi Dayanand University, Rohtak, Haryana, 124001, India
| | - Vikrant Sharma
- Centre for Biotechnology, Maharshi Dayanand University, Rohtak, Haryana, 124001, India
- Department of Virology, Postgraduate Institute of Medical Education & Research (PGIMER), Chandigarh, 160012, India
| | - Sulochana Kaushik
- Centre for Biotechnology, Maharshi Dayanand University, Rohtak, Haryana, 124001, India
| | - Promod K Mehta
- Centre for Biotechnology, Maharshi Dayanand University, Rohtak, Haryana, 124001, India
| | - Sandeep Singh
- Department of Biochemistry, Maharshi Dayanand University, Rohtak, Haryana, 124001, India
| | - Samander Kaushik
- Centre for Biotechnology, Maharshi Dayanand University, Rohtak, Haryana, 124001, India
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Ji C, Xue S, Yu M, Liu J, Zhang Q, Zuo F, Zheng Q, Zhao L, Zhang H, Cao J, Wang K, Liu W, Zheng W. Rapid Detection of SARS-CoV-2 Virus Using Dual Reverse Transcriptional Colorimetric Loop-Mediated Isothermal Amplification. ACS OMEGA 2021; 6:8837-8849. [PMID: 33842755 PMCID: PMC8008787 DOI: 10.1021/acsomega.0c05781] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 03/09/2021] [Indexed: 05/12/2023]
Abstract
The outbreak and pandemic of COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has developed into a public health emergency of international concern. The rapid and accurate detection of the virus is a critical means to prevent and control the disease. Herein, we provide a novel, rapid, and simple approach, named dual reverse transcriptional colorimetric loop-mediated isothermal amplification (dRT-cLAMP) assay, to accelerate the detection of the SARS-CoV-2 virus without using expensive equipment. The result of this assay is shown by color change and is easily detected by the naked eye. To improve the detection accuracy, we included two primer sets that specifically target the viral orf1ab and N genes in the same reaction mixture. Our assay can detect the synthesized SARS-CoV-2 N and orf1ab genes at a low level of 100 copies/μL. Sequence alignment analysis of the two synthesized genes and those of 9968 published SARS-CoV-2 genomes and 17 genomes of other pathogens from the same infection site or similar symptoms as COVID-19 revealed that the primers for the dRT-cLAMP assay are highly specific. Our assay of 27 clinical samples of SARS-CoV-2 virus and 27 standard-added environmental simulation samples demonstrated that compared to the commercial kits, the consistency of the positive, negative, and probable clinical samples was 100, 92.31, and 44.44%, respectively. Moreover, our results showed that the positive, but not negative, standard-added samples displayed a naked-eye-detectable color change. Together, our results demonstrate that the dRT-cLAMP assay is a feasible detection assay for SARS-CoV-2 virus and is of great significance since rapid onsite detection of the virus is urgently needed at the ports of entry, health care centers, and for internationally traded goods.
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Affiliation(s)
- Chao Ji
- State
Key Laboratory for Conservation and Utilization of Bio-Resources in
Yunnan, Yunnan Agricultural University, Kunming 650201, P. R. China
- Key
Laboratory for Agro-Biodiversity and Pest Control of Ministry of Education, Yunnan Agricultural University, Kunming 650201, P. R. China
- Laboratory
for Quality Control and Traceability of Food, Tianjin Normal University, Tianjin 300387, P. R. China
| | - Shuxia Xue
- Laboratory
for Quality Control and Traceability of Food, Tianjin Normal University, Tianjin 300387, P. R. China
| | - Min Yu
- Department
of Gynecologic Oncology, Tianjin Medical University Cancer Institute
and Hospital, National Clinical Research
Center for Cancer, Tianjin 300060, P. R. China
| | - Jinyu Liu
- Laboratory
for Quality Control and Traceability of Food, Tianjin Normal University, Tianjin 300387, P. R. China
| | - Qin Zhang
- Laboratory
for Quality Control and Traceability of Food, Tianjin Normal University, Tianjin 300387, P. R. China
| | - Feng Zuo
- Tianjin
Customs District, Tianjin 300308, China
| | - Qiuyue Zheng
- Key Laboratory
of Biotechnology and Bioresources Utilization of Ministry of Education,
College of Life Science, Dalian Minzu University, Dalian 116600, P. R. China
| | | | | | - Jijuan Cao
- Key Laboratory
of Biotechnology and Bioresources Utilization of Ministry of Education,
College of Life Science, Dalian Minzu University, Dalian 116600, P. R. China
| | - Ke Wang
- Department
of Gynecologic Oncology, Tianjin Medical University Cancer Institute
and Hospital, National Clinical Research
Center for Cancer, Tianjin 300060, P. R. China
| | - Wei Liu
- Tianjin
Customs District, Tianjin 300308, China
| | - Wenjie Zheng
- Laboratory
for Quality Control and Traceability of Food, Tianjin Normal University, Tianjin 300387, P. R. China
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Tomar PS, Kumar JS, Patel S, Sharma S. Polymerase Spiral Reaction Assay for Rapid and Real Time Detection of West Nile Virus From Clinical Samples. Front Cell Infect Microbiol 2020; 10:426. [PMID: 32984063 PMCID: PMC7492713 DOI: 10.3389/fcimb.2020.00426] [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: 11/13/2019] [Accepted: 07/13/2020] [Indexed: 12/02/2022] Open
Abstract
West Nile virus (WNV) is a mosquito-borne virus of public health importance. Currently, there is no FDA approved vaccine available against WNV infection in humans. Therefore, the early diagnosis of the WNV infection is important for epidemiologic control and timely clinical management in areas where multiple Flaviviruses are endemic. The present study aimed to develop reverse transcription polymerase spiral reaction (RT-PSR) assay that rapidly and accurately detects the envelope (env) gene of WNV. RT-PSR assay was optimized at 63°C for 60 min using real-time turbidimeter or visual detection by the addition of SYBR Green I dye. The standard curve for RT-PSR assay was generated using the 10-fold serial dilutions of in vitro transcribed WNV RNA. To determine the detection limit of RT-PSR assay, an amplified product of conventional RT-PCR was in vitro transcribed as per standard protocol. The detection limit of the newly developed RT-PSR assay was compared with that of conventional RT-PCR and CDC reported TaqMan real-time RT-PCR using a serial 10-fold dilution of IVT WNV RNA. The detection limit of RT-PSR was found to be 1 RNA copy, which is 100-fold higher than that of conventional RT-PCR (100 copies). This suggests that RT-PSR assay is a valuable diagnostic tool for rapid and real-time detection of WNV in acute-phase serum samples. The assay was validated with a panel of 107 WNV suspected human clinical samples with signs of acute posterior uveitis and onset of febrile illness. Out of 107 samples, 30 were found positive by RT-PSR assay. The specificities of the selected primer sets were established by the absence of cross-reactivity with other closely related members viruses of the Flaviviruses, Alphaviruses, and Morbilliviruses groups. No cross-reactivity was observed with other viruses. To best of our knowledge, this is the first report describing the RT-PSR assay for the detection of RNA virus (WNV) in clinical samples. RT-PSR is a high throughput method and more than 30 reactions can be run at once in real-time turbidimeter. PSR assay has potential to be used for a rapid screening of large number of clinical samples in endemic areas during an outbreak.
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Affiliation(s)
- Priyanka Singh Tomar
- Division of Virology, Defence Research and Development Establishment, Gwalior, India
| | - Jyoti S Kumar
- Division of Virology, Defence Research and Development Establishment, Gwalior, India
| | - Sapan Patel
- School of Studies in Botany, Jiwaji University, Gwalior, India
| | - Shashi Sharma
- Division of Virology, Defence Research and Development Establishment, Gwalior, India
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Deepthi KG, Prabagaran SR. Ocular bacterial infections: Pathogenesis and diagnosis. Microb Pathog 2020; 145:104206. [PMID: 32330515 DOI: 10.1016/j.micpath.2020.104206] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 04/14/2020] [Accepted: 04/14/2020] [Indexed: 12/19/2022]
Abstract
The human eye is a rigid asymmetric structure with unique defence system. Despite considerable resident microbiota, eye is exposed to external environment where a range of microorganisms also inhabits. Opportunistically, some of these microorganisms could associate with eye pathogen that could contact incidentally, leading to destructive visual consequences. Among such microbiota, bacteria form the major proportion concerning ocular complications worldwide. The succession of genome based approach through 16S rRNA gene based identification tremendously augmented the knowledge on diversity of ocular surface bacteria. Such evidence suggests that while few bacteria contribute towards normal ocular functions, considerable number of bacteria play active role in pathophysiology of ocular diseases. Thus, understanding the complexity of ocular microflora not only throw light on their critical role towards normal function of the eye, but also enlighten on certain visual exigencies. Under these circumstances, development of a rapid, reliable and cost effective method is essential that eventually evolve as a routine diagnostic protocol. Such precise prognostic modalities facilitate ophthalmologists to formulate pioneering therapeutics towards challenging ocular diseases.
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A need to raise the bar - A systematic review of temporal trends in diagnostics for Japanese encephalitis virus infection, and perspectives for future research. Int J Infect Dis 2020; 95:444-456. [PMID: 32205287 PMCID: PMC7294235 DOI: 10.1016/j.ijid.2020.03.039] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 03/09/2020] [Accepted: 03/15/2020] [Indexed: 12/14/2022] Open
Abstract
Japanese encephalitis virus (JEV) remains a leading cause of neurological infection in Asia. A systematic review identified 20,212 published human cases of laboratory-confirmed JEV infections from 205 studies. 15,167 (75%) of cases were confirmed with the lowest confidence diagnostic test, i.e., level 3 or 4, or level 4. Only 109 (53%) of the studies reported contemporaneous testing for dengue-specific antibodies. A fundamental pre-requisite for the control of JE is lacking — that of a simple and specific diagnostic procedure that can be adapted for point-of-care tests and readily used throughout JE endemic regions of the world.
Objective Japanese encephalitis virus infection (JE) remains a leading cause of neurological disease in Asia, mainly involving individuals living in remote areas with limited access to treatment centers and diagnostic facilities. Laboratory confirmation is fundamental for the justification and implementation of vaccination programs. We reviewed the literature on historical developments and current diagnostic capability worldwide, to identify knowledge gaps and instill urgency to address them. Methods Searches were performed in Web of Science and PubMed using the term 'Japanese encephalitis' up to 13th October 2019. Studies reporting laboratory-confirmed symptomatic JE cases in humans were included, and data on details of diagnostic tests were extracted. A JE case was classified according to confirmatory levels (Fischer et al., 2008; Campbell et al., 2011; Pearce et al., 2018; Heffelfinger et al., 2017), where level 1 represented the highest level of confidence. Findings 20,212 published JE cases were identified from 205 studies. 15,167 (75%) of these positive cases were confirmed with the lowest-confidence diagnostic tests (level 3 or 4, or level 4). Only 109 (53%) of the studies reported contemporaneous testing for dengue-specific antibodies. Conclusion A fundamental pre-requisite for the control of JEV is lacking — that of a simple and specific diagnostic procedure that can be adapted for point-of-care tests and readily used throughout JE-endemic regions of the world.
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