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Hallmann E, Masny A, Poznańska A, Pozo F, Casas I, Brydak LB. Molecular Determinants of Drug Resistance and Mutation Patterns in Influenza Viruses Circulating in Poland Across Multiple Epidemic Seasons: Implications for Vaccination Strategies. Med Sci Monit 2024; 30:e942125. [PMID: 38446736 PMCID: PMC10926709 DOI: 10.12659/msm.942125] [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: 08/10/2023] [Accepted: 01/15/2024] [Indexed: 03/08/2024] Open
Abstract
BACKGROUND According to the WHO, up to 650 000 people die each year from seasonal flu-related respiratory illnesses. The most effective method of fighting the virus is seasonal vaccination. However, if an infection does occur, antiviral medications should be used as soon as possible. No studies of drug resistance in influenza viruses circulating in Poland have been systematically conducted. Therefore, the aim of the present study was to investigate the drug resistance and genetic diversity of influenza virus strains circulating in Poland by determining the presence of mutations in the neuraminidase gene. MATERIAL AND METHODS A total of 258 clinical specimens were collected during the 2016-2017, 2017-2018, and 2018-2019 epidemic seasons. The samples containing influenza A and B were analyzed by RT-PCR and Sanger sequencing. RESULTS Differences were found between the influenza virus strains detected in different epidemic seasons, demonstrating the occurrence of mutations. Influenza A virus was found to be more genetically variable than influenza B virus (P<0.001, Kruskal-Wallis test). However, there was no significant difference in the resistance prevalence between the influenza A subtypes A/H1N1/pdm09 (4.8%) and A/H3N2/ (6.1%). In contrast, more mutations of drug-resistance genes were found in the influenza B virus (P<0.001, chi-square test). In addition, resistance mutations appeared en masse in vaccine strains circulating in unvaccinated populations. CONCLUSIONS It seems important to determine whether the influenza virus strains tested for drug resistance as part of global influenza surveillance are equally representative of viruses circulating in populations with high and low vaccination rates, for all countries. Our results suggest that countries with low levels of influenza immunization may constitute reservoirs of drug-resistant influenza viruses.
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Affiliation(s)
- Ewelina Hallmann
- Department of Virology, National Institute of Public Health NIH – National Research Institute, Warsaw, Poland
| | - Aleksander Masny
- Department of Virology, National Institute of Public Health NIH – National Research Institute, Warsaw, Poland
| | - Anna Poznańska
- Department of Population Health Monitoring and Analysis, National Institute of Public Health NIH – National Research Institute, Warsaw, Poland
| | - Francisco Pozo
- National Center for Microbiology, Instituto de Salud Carlos III, Majadahonda, Spain
- CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | - Inmaculada Casas
- National Center for Microbiology, Instituto de Salud Carlos III, Majadahonda, Spain
- CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | - Lidia Bernadeta Brydak
- Department of Virology, National Institute of Public Health NIH – National Research Institute, Warsaw, Poland
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Zhang M, Zhou J, Ni R, Zhao X, Chen Y, Sun Y, Liu Z, Han X, Luo C, Fu X, Shao Y. Genomic Analyses Uncover Evolutionary Features of Influenza A/H3N2 Viruses in Yunnan Province, China, from 2017 to 2022. Viruses 2024; 16:138. [PMID: 38257838 PMCID: PMC10820241 DOI: 10.3390/v16010138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2023] [Revised: 01/13/2024] [Accepted: 01/16/2024] [Indexed: 01/24/2024] Open
Abstract
Influenza A viruses evolve at a high rate of nucleotide substitution, thereby requiring continuous monitoring to determine the efficacy of vaccines and antiviral drugs. In the current study, we performed whole-genome sequencing analyses of 253 influenza A/H3N2 strains from Yunnan Province, China, during 2017-2022. The hemagglutinin (HA) segments of Yunnan A/H3N2 strains isolated during 2017-2018 harbored a high genetic diversity due to heterogeneous distribution across branches. The mutation regularity of the predominant antigenic epitopes of HA segments in Yunnan was inconsistent in different years. Some important functional mutations in gene segments associated with viral adaptation and drug tolerance were revealed. The rapid genomic evolution of Yunnan A/H3N2 strains from 2017 to 2022 mainly concentrated on segments, i.e., matrix protein 2 (M2), non-structural protein 1 (NS1), neuraminidase (NA), NS2, and HA, with a high overall non-synonymous/synonymous substitution ratio (dN/dS). Our results highlighted a decline in vaccine efficacy against the A/H3N2 circulating strains, particularly against the Yunnan 2021-2022 A/H3N2 strains. These findings aid our understanding of evolutionary characteristics and epidemiological monitoring of the A/H3N2 viruses and provide in-depth insights into the protective efficacy of influenza vaccines.
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Affiliation(s)
- Meiling Zhang
- Department of Acute Infectious Diseases Control and Prevention, Yunnan Center for Disease Control and Prevention, Kunming 650022, China; (M.Z.); (J.Z.); (R.N.); (X.Z.); (Y.C.); (Y.S.); (Z.L.); (X.H.); (C.L.)
| | - Jienan Zhou
- Department of Acute Infectious Diseases Control and Prevention, Yunnan Center for Disease Control and Prevention, Kunming 650022, China; (M.Z.); (J.Z.); (R.N.); (X.Z.); (Y.C.); (Y.S.); (Z.L.); (X.H.); (C.L.)
| | - Ruize Ni
- Department of Acute Infectious Diseases Control and Prevention, Yunnan Center for Disease Control and Prevention, Kunming 650022, China; (M.Z.); (J.Z.); (R.N.); (X.Z.); (Y.C.); (Y.S.); (Z.L.); (X.H.); (C.L.)
| | - Xiaonan Zhao
- Department of Acute Infectious Diseases Control and Prevention, Yunnan Center for Disease Control and Prevention, Kunming 650022, China; (M.Z.); (J.Z.); (R.N.); (X.Z.); (Y.C.); (Y.S.); (Z.L.); (X.H.); (C.L.)
| | - Yaoyao Chen
- Department of Acute Infectious Diseases Control and Prevention, Yunnan Center for Disease Control and Prevention, Kunming 650022, China; (M.Z.); (J.Z.); (R.N.); (X.Z.); (Y.C.); (Y.S.); (Z.L.); (X.H.); (C.L.)
| | - Yanhong Sun
- Department of Acute Infectious Diseases Control and Prevention, Yunnan Center for Disease Control and Prevention, Kunming 650022, China; (M.Z.); (J.Z.); (R.N.); (X.Z.); (Y.C.); (Y.S.); (Z.L.); (X.H.); (C.L.)
| | - Zhaosheng Liu
- Department of Acute Infectious Diseases Control and Prevention, Yunnan Center for Disease Control and Prevention, Kunming 650022, China; (M.Z.); (J.Z.); (R.N.); (X.Z.); (Y.C.); (Y.S.); (Z.L.); (X.H.); (C.L.)
| | - Xiaoyu Han
- Department of Acute Infectious Diseases Control and Prevention, Yunnan Center for Disease Control and Prevention, Kunming 650022, China; (M.Z.); (J.Z.); (R.N.); (X.Z.); (Y.C.); (Y.S.); (Z.L.); (X.H.); (C.L.)
| | - Chunrui Luo
- Department of Acute Infectious Diseases Control and Prevention, Yunnan Center for Disease Control and Prevention, Kunming 650022, China; (M.Z.); (J.Z.); (R.N.); (X.Z.); (Y.C.); (Y.S.); (Z.L.); (X.H.); (C.L.)
| | - Xiaoqing Fu
- Department of Acute Infectious Diseases Control and Prevention, Yunnan Center for Disease Control and Prevention, Kunming 650022, China; (M.Z.); (J.Z.); (R.N.); (X.Z.); (Y.C.); (Y.S.); (Z.L.); (X.H.); (C.L.)
| | - Yong Shao
- State Key Laboratory of Genetic Resources and Evolution, Chinese Academy of Sciences, Kunming Institute of Zoology, Kunming 650201, China
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3
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Nabakooza G, Galiwango R, Frost SDW, Kateete DP, Kitayimbwa JM. Molecular Epidemiology and Evolutionary Dynamics of Human Influenza Type-A Viruses in Africa: A Systematic Review. Microorganisms 2022; 10:900. [PMID: 35630344 PMCID: PMC9145646 DOI: 10.3390/microorganisms10050900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 03/21/2022] [Accepted: 03/22/2022] [Indexed: 02/01/2023] Open
Abstract
Genomic characterization of circulating influenza type-A viruses (IAVs) directs the selection of appropriate vaccine formulations and early detection of potentially pandemic virus strains. However, longitudinal data on the genomic evolution and transmission of IAVs in Africa are scarce, limiting Africa's benefits from potential influenza control strategies. We searched seven databases: African Journals Online, Embase, Global Health, Google Scholar, PubMed, Scopus, and Web of Science according to the PRISMA guidelines for studies that sequenced and/or genomically characterized Africa IAVs. Our review highlights the emergence and diversification of IAVs in Africa since 1993. Circulating strains continuously acquired new amino acid substitutions at the major antigenic and potential N-linked glycosylation sites in their hemagglutinin proteins, which dramatically affected vaccine protectiveness. Africa IAVs phylogenetically mixed with global strains forming strong temporal and geographical evolution structures. Phylogeographic analyses confirmed that viral migration into Africa from abroad, especially South Asia, Europe, and North America, and extensive local viral mixing sustained the genomic diversity, antigenic drift, and persistence of IAVs in Africa. However, the role of reassortment and zoonosis remains unknown. Interestingly, we observed substitutions and clades and persistent viral lineages unique to Africa. Therefore, Africa's contribution to the global influenza ecology may be understated. Our results were geographically biased, with data from 63% (34/54) of African countries. Thus, there is a need to expand influenza surveillance across Africa and prioritize routine whole-genome sequencing and genomic analysis to detect new strains early for effective viral control.
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Affiliation(s)
- Grace Nabakooza
- Department of Immunology and Molecular Biology, Makerere University, Old Mulago Hill Road, P.O. Box 7072, Kampala 256, Uganda;
- UVRI Centre of Excellence in Infection and Immunity Research and Training (MUII-Plus), Makerere University, Plot No: 51-59 Nakiwogo Road, P.O. Box 49, Entebbe 256, Uganda; (R.G.); (J.M.K.)
| | - Ronald Galiwango
- UVRI Centre of Excellence in Infection and Immunity Research and Training (MUII-Plus), Makerere University, Plot No: 51-59 Nakiwogo Road, P.O. Box 49, Entebbe 256, Uganda; (R.G.); (J.M.K.)
- Centre for Computational Biology, Uganda Christian University, Plot 67-173, Bishop Tucker Road, P.O. Box 4, Mukono 256, Uganda
- African Center of Excellence in Bioinformatics and Data Intensive Sciences, Infectious Diseases Institute, Makerere University, Kampala 256, Uganda
| | - Simon D. W. Frost
- Microsoft Research, Redmond, 14820 NE 36th Street, Washington, DC 98052, USA;
- London School of Hygiene & Tropical Medicine (LSHTM), University of London, Keppel Street, Bloomsbury, London WC1E7HT, UK
| | - David P. Kateete
- Department of Immunology and Molecular Biology, Makerere University, Old Mulago Hill Road, P.O. Box 7072, Kampala 256, Uganda;
- UVRI Centre of Excellence in Infection and Immunity Research and Training (MUII-Plus), Makerere University, Plot No: 51-59 Nakiwogo Road, P.O. Box 49, Entebbe 256, Uganda; (R.G.); (J.M.K.)
| | - John M. Kitayimbwa
- UVRI Centre of Excellence in Infection and Immunity Research and Training (MUII-Plus), Makerere University, Plot No: 51-59 Nakiwogo Road, P.O. Box 49, Entebbe 256, Uganda; (R.G.); (J.M.K.)
- Centre for Computational Biology, Uganda Christian University, Plot 67-173, Bishop Tucker Road, P.O. Box 4, Mukono 256, Uganda
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Lagare A, Rajatonirina S, Testa J, Mamadou S. The epidemiology of seasonal influenza after the 2009 influenza pandemic in Africa: a systematic review. Afr Health Sci 2020; 20:1514-1536. [PMID: 34394213 PMCID: PMC8351825 DOI: 10.4314/ahs.v20i4.5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Background Influenza infection is a serious public health problem that causes an estimated 3 to 5 million cases and 250,000 deaths worldwide every year. The epidemiology of influenza is well-documented in high- and middle-income countries, however minimal effort had been made to understand the epidemiology, burden and seasonality of influenza in Africa. This study aims to assess the state of knowledge of seasonal influenza epidemiology in Africa and identify potential data gaps for policy formulation following the 2009 pandemic. Method We reviewed articles from Africa published into four databases namely: MEDLINE (PubMed), Google Scholar, Cochrane Library and Scientific Research Publishing from 2010 to 2019. Results We screened titles and abstracts of 2070 studies of which 311 were selected for full content evaluation and 199 studies were considered. Selected articles varied substantially on the basis of the topics they addressed covering the field of influenza surveillance (n=80); influenza risk factors and co-morbidities (n=15); influenza burden (n=37); influenza vaccination (n=40); influenza and other respiratory pathogens (n=22) and influenza diagnosis (n=5). Conclusion Significant progress has been made since the last pandemic in understanding the influenza epidemiology in Africa. However, efforts still remain for most countries to have sufficient data to allow countries to prioritize strategies for influenza prevention and control.
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Affiliation(s)
- Adamou Lagare
- Centre de Recherche Médicale et Sanitaire (CERMES), Niamey, Niger
| | | | - Jean Testa
- Centre de Recherche Médicale et Sanitaire (CERMES), Niamey, Niger
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5
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Monamele CG, Kengne-Nde C, Munshili Njifon HL, Njankouo MR, Kenmoe S, Njouom R. Clinical signs predictive of influenza virus infection in Cameroon. PLoS One 2020; 15:e0236267. [PMID: 32701976 PMCID: PMC7377385 DOI: 10.1371/journal.pone.0236267] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 07/01/2020] [Indexed: 11/18/2022] Open
Abstract
Influenza virus accounts for majority of respiratory virus infections in Cameroon. According to the World Health Organization (WHO), influenza-like illnesses (ILI) are identified by a measured temperature of ≥38°C and cough, with onset within the past 10 days. Other symptoms could as well be observed however, none of these are specific to influenza alone. This study aimed to determine symptom based predictors of influenza virus infection in Cameroon. Individuals with ILI were recruited from 2009-2018 in sentinel sites of the influenza surveillance system in Cameroon according to the WHO case definition. Individual data collection forms accompanied each respiratory sample and contained clinical data. Samples were analyzed for influenza using the gold standard assay. Two statistical methods were compared to determine the most reliable clinical predictors of influenza virus activity in Cameroon: binomial logistic predictive model and random forest model. Analyses were performed in R version 3.5.2. A total of 11816 participants were recruited, of which, 24.0% were positive for influenza virus. Binomial logistic predictive model revealed that the presence of cough, rhinorrhoea, headache and myalgia are significant predictors of influenza positivity. The prediction model had a sensitivity of 75.6%, specificity of 46.6% and AUC of 66.7%. The random forest model categorized the reported symptoms according to their degree of importance in predicting influenza virus infection. Myalgia had a 2-fold higher value in predicting influenza virus infection compared to any other symptom followed by arthralgia, head ache, rhinorrhoea and sore throat. The model had a OOB error rate of 25.86%. Analysis showed that the random forest model had a better performance over the binomial regression model in predicting influenza infection. Rhinorrhoea, headache and myalgia were symptoms reported by both models as significant predictors of influenza infection in Cameroon. These symptoms could be used by clinicians in their decision to treat patients.
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Affiliation(s)
| | - Cyprien Kengne-Nde
- Evaluation and Research Unit, National AIDS Control Committee, Yaounde, Cameroon
| | | | | | - Sebastien Kenmoe
- Virology Department, Centre Pasteur of Cameroon, Yaounde, Cameroon
| | - Richard Njouom
- Virology Department, Centre Pasteur of Cameroon, Yaounde, Cameroon
- * E-mail:
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6
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Alroy KA, Gwom LC, Ndongo CB, Kenmoe S, Monamele G, Clara A, Whitaker B, Manga H, Tayimetha CY, Tseuko D, Etogo B, Pasi O, Etoundi AG, Seukap E, Njouom R, Balajee A. Strengthening timely detection and reporting of unusual respiratory events from health facilities in Yaoundé, Cameroon. Influenza Other Respir Viruses 2020; 14:122-128. [PMID: 31923349 PMCID: PMC7040971 DOI: 10.1111/irv.12684] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 09/13/2019] [Accepted: 09/16/2019] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND The International Health Regulations state that early detection and immediate reporting of unusual health events is important for early warning and response systems. OBJECTIVE To describe a pilot surveillance program established in health facilities in Yaoundé, Cameroon in 2017 which aimed to enable detection and reporting of public health events. METHODS Cameroon's Ministry of Health, in partnership with the US Centers for Disease Control and Prevention, Cameroon Pasteur Center, and National Public Health Laboratory, implemented event-based surveillance (EBS) in nine Yaoundé health facilities. Four signals were defined that could indicate possible public health events, and a reporting, triage, and verification system was established among partner organizations. A pre-defined laboratory algorithm was defined, and a series of workshops trained health facilities, laboratory, and public health staff for surveillance implementation. RESULTS From May 2017 to January 2018, 30 signals were detected, corresponding to 15 unusual respiratory events. All health facilities reported a signal at least once, and more than three-quarters of health facilities reported ≥2 times. Among specimens tested, the pathogens detected included Klebsiella pneumoniae, Moraxella catarrhalis, Streptococcus pneumoniae, Haemophilus influenza, Staphylococcus aureus, Pneumocystis jiroveci, influenza A (H1N1) virus, rhinovirus, and adenovirus. CONCLUSIONS The events detected in this pilot were caused by routine respiratory bacteria and viruses, and no novel influenza viruses or other emerging respiratory threats were identified. The surveillance system, however, strengthened relationships and communication linkages between health facilities and public health authorities. Astute clinicians can play a critical role in early detection and EBS is one approach that may enable reporting of emerging outbreaks and public health events.
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Affiliation(s)
- Karen A. Alroy
- Division of Viral DiseasesNational Center for Immunization and Respiratory DiseasesCenters for Disease Control and PreventionAtlantaGAUSA
| | - Luc Christian Gwom
- Division for the Fight against Disease, Epidemics and PandemicsMinistry of HealthYaoundéCameroon
| | | | | | | | - Alexey Clara
- Division of Viral DiseasesNational Center for Immunization and Respiratory DiseasesCenters for Disease Control and PreventionAtlantaGAUSA
| | - Brett Whitaker
- Division of Viral DiseasesNational Center for Immunization and Respiratory DiseasesCenters for Disease Control and PreventionAtlantaGAUSA
| | - Henri Manga
- National Public Health LaboratoryMinistry of HealthYaoundéCameroon
| | | | - Dorine Tseuko
- National Public Health LaboratoryMinistry of HealthYaoundéCameroon
| | - Bienvenu Etogo
- National Public Health LaboratoryMinistry of HealthYaoundéCameroon
| | - Omer Pasi
- Division of Global Health ProtectionCenter for Global HealthAtlantaGAUSA
| | - Alain Georges Etoundi
- Division for the Fight against Disease, Epidemics and PandemicsMinistry of HealthYaoundéCameroon
| | - Elise Seukap
- Division for the Fight against Disease, Epidemics and PandemicsMinistry of HealthYaoundéCameroon
| | | | - Arunmozhi Balajee
- Division of Viral DiseasesNational Center for Immunization and Respiratory DiseasesCenters for Disease Control and PreventionAtlantaGAUSA
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7
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Owuor DC, Ngoi JM, Otieno JR, Otieno GP, Nyasimi FM, Nyiro JU, Agoti CN, Chaves SS, Nokes DJ. Genetic characterization of influenza A(H3N2) viruses circulating in coastal Kenya, 2009-2017. Influenza Other Respir Viruses 2020; 14:320-330. [PMID: 31943817 PMCID: PMC7182596 DOI: 10.1111/irv.12717] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 12/19/2019] [Accepted: 12/20/2019] [Indexed: 12/01/2022] Open
Abstract
Background Influenza viruses evolve rapidly and undergo immune driven selection, especially in the hemagglutinin (HA) protein. We report amino acid changes affecting antigenic epitopes and receptor‐binding sites of A(H3N2) viruses circulating in Kilifi, Kenya, from 2009 to 2017. Methods Next‐generation sequencing (NGS) was used to generate A(H3N2) virus genomic data from influenza‐positive specimens collected from hospital admissions and health facility outpatients presenting with acute respiratory illness to health facilities within the Kilifi Health and Demographic Surveillance System. Full‐length HA sequences were utilized to characterize A(H3N2) virus genetic and antigenic changes. Results From 186 (90 inpatient and 96 outpatient) influenza A virus‐positive specimens processed, 101 A(H3N2) virus whole genomes were obtained. Among viruses identified in inpatient specimens from 2009 to 2015, divergence of circulating A(H3N2) viruses from the vaccine strains A/Perth/16/2009, A/Texas/50/2012, and A/Switzerland/9715293/2013 formed 6 genetic clades (A/Victoria/208/2009‐like, 3B, 3C, 3C.2a, 4, and 7). Among viruses identified in outpatient specimens from 2015 to 2017, divergence of circulating A(H3N2) viruses from vaccine strain A/Hong Kong/4801/2014 formed clade 3C.2a, subclades 3C.2a2 and 3C.2a3, and subgroup 3C.2a1b. Several amino acid substitutions were associated with the continued genetic evolution of A(H3N2) strains in circulation. Conclusions Our results suggest continuing evolution of currently circulating A(H3N2) viruses in Kilifi, coastal Kenya and suggest the need for continuous genetic and antigenic viral surveillance of circulating seasonal influenza viruses with broad geographic representation to facilitate prompt and efficient selection of influenza strains for inclusion in future influenza vaccines.
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Affiliation(s)
- D Collins Owuor
- Virus Epidemiology and Control Research Group, Kenya Medical Research Institute (KEMRI) - Wellcome Trust Research Programme, Kilifi, Kenya
| | - Joyce M Ngoi
- Virus Epidemiology and Control Research Group, Kenya Medical Research Institute (KEMRI) - Wellcome Trust Research Programme, Kilifi, Kenya
| | - James R Otieno
- Virus Epidemiology and Control Research Group, Kenya Medical Research Institute (KEMRI) - Wellcome Trust Research Programme, Kilifi, Kenya
| | - Grieven P Otieno
- Virus Epidemiology and Control Research Group, Kenya Medical Research Institute (KEMRI) - Wellcome Trust Research Programme, Kilifi, Kenya
| | - Festus M Nyasimi
- Virus Epidemiology and Control Research Group, Kenya Medical Research Institute (KEMRI) - Wellcome Trust Research Programme, Kilifi, Kenya
| | - Joyce U Nyiro
- Virus Epidemiology and Control Research Group, Kenya Medical Research Institute (KEMRI) - Wellcome Trust Research Programme, Kilifi, Kenya
| | - Charles N Agoti
- Virus Epidemiology and Control Research Group, Kenya Medical Research Institute (KEMRI) - Wellcome Trust Research Programme, Kilifi, Kenya.,School of Health and Human Sciences, Pwani University, Kilifi, Kenya
| | - Sandra S Chaves
- Influenza Division, Centres for Disease Control and Prevention (CDC), Nairobi, Kenya
| | - D James Nokes
- Virus Epidemiology and Control Research Group, Kenya Medical Research Institute (KEMRI) - Wellcome Trust Research Programme, Kilifi, Kenya.,School of Life Sciences and Zeeman Institute for Systems Biology and Infectious Disease Epidemiology Research (SBIDER), University of Warwick, Coventry, UK
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8
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Shi W, Ke C, Fang S, Li J, Song H, Li X, Hu T, Wu J, Chen T, Yi L, Song Y, Wang X, Xing W, Huang W, Xiao H, Liang L, Peng B, Wu W, Liu H, Liu WJ, Holmes EC, Gao GF, Wang D. Co-circulation and persistence of multiple A/H3N2 influenza variants in China. Emerg Microbes Infect 2019; 8:1157-1167. [PMID: 31373538 PMCID: PMC6713139 DOI: 10.1080/22221751.2019.1648183] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The spread of influenza A/H3N2 variants possessing the hemagglutinin 121 K mutation and the unexpectedly high incidence of influenza in the 2017–2018 northern hemisphere influenza season have raised serious concerns about the next pandemic. We summarized the national surveillance data of seasonal influenza in China and identified marked differences in influenza epidemics between northern and southern China, particularly the predominating subtype and the presence of an additional summer peak in southern China. Notably, a minor spring peak of influenza caused by a different virus subtype was also observed. We also revealed that the 3C.2a lineage was dominant from the summer of 2015 to the end of the 2015–2016 peak season in China, after which the 3C.2a2 lineage predominated despite the importation and co-circulation of the 121 K variants of 3C.2a1 and 3C.2a3 lineages at the global level. Finally, an analysis based on genetic distances revealed a delay in A/H3N2 vaccine strain update. Overall, our results highlight the complicated circulation pattern of seasonal influenza in China and the necessity for a timely vaccine strain update worldwide.
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Affiliation(s)
- Weifeng Shi
- d Key Laboratory of Etiology and Epidemiology of Emerging Infectious Diseases in Universities of Shandong, Shandong First Medical University & Shandong Academy of Medical Sciences , Taian , People's Republic of China
| | - Changwen Ke
- e Guangdong Provincial Center for Disease Control and Prevention , Guangzhou , People's Republic of China
| | - Shisong Fang
- f Division of Microbiology Test, Shenzhen Centre for Disease Control and Prevention , Shenzhen , People's Republic of China
| | - Juan Li
- d Key Laboratory of Etiology and Epidemiology of Emerging Infectious Diseases in Universities of Shandong, Shandong First Medical University & Shandong Academy of Medical Sciences , Taian , People's Republic of China
| | - Hao Song
- g Chinese Academy of Sciences, Research Network of Immunity and Health (RNIH), Beijing Institutes of Life Science , Beijing , People's Republic of China
| | - Xiyan Li
- a Chinese National Influenza Center, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention , Beijing , People's Republic of China.,b WHO Collaborating Center for Reference and Research on Influenza , Beijing , People's Republic of China.,c Key Laboratory for Medical Virology, National Health Commission , Beijing , People's Republic of China
| | - Tao Hu
- d Key Laboratory of Etiology and Epidemiology of Emerging Infectious Diseases in Universities of Shandong, Shandong First Medical University & Shandong Academy of Medical Sciences , Taian , People's Republic of China
| | - Jie Wu
- e Guangdong Provincial Center for Disease Control and Prevention , Guangzhou , People's Republic of China
| | - Tao Chen
- a Chinese National Influenza Center, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention , Beijing , People's Republic of China.,b WHO Collaborating Center for Reference and Research on Influenza , Beijing , People's Republic of China.,c Key Laboratory for Medical Virology, National Health Commission , Beijing , People's Republic of China
| | - Lina Yi
- e Guangdong Provincial Center for Disease Control and Prevention , Guangzhou , People's Republic of China.,h Guangdong Provincial Institution of Public Health, Guangdong Provincial Center for Disease Control and Prevention , Guangzhou , People's Republic of China
| | - Yingchao Song
- e Guangdong Provincial Center for Disease Control and Prevention , Guangzhou , People's Republic of China
| | - Xin Wang
- f Division of Microbiology Test, Shenzhen Centre for Disease Control and Prevention , Shenzhen , People's Republic of China
| | - Weijia Xing
- d Key Laboratory of Etiology and Epidemiology of Emerging Infectious Diseases in Universities of Shandong, Shandong First Medical University & Shandong Academy of Medical Sciences , Taian , People's Republic of China
| | - Weijuan Huang
- a Chinese National Influenza Center, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention , Beijing , People's Republic of China.,b WHO Collaborating Center for Reference and Research on Influenza , Beijing , People's Republic of China.,c Key Laboratory for Medical Virology, National Health Commission , Beijing , People's Republic of China
| | - Hong Xiao
- e Guangdong Provincial Center for Disease Control and Prevention , Guangzhou , People's Republic of China
| | - Lijun Liang
- e Guangdong Provincial Center for Disease Control and Prevention , Guangzhou , People's Republic of China
| | - Bo Peng
- f Division of Microbiology Test, Shenzhen Centre for Disease Control and Prevention , Shenzhen , People's Republic of China
| | - Weihua Wu
- f Division of Microbiology Test, Shenzhen Centre for Disease Control and Prevention , Shenzhen , People's Republic of China
| | - Hui Liu
- f Division of Microbiology Test, Shenzhen Centre for Disease Control and Prevention , Shenzhen , People's Republic of China
| | - William J Liu
- a Chinese National Influenza Center, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention , Beijing , People's Republic of China.,b WHO Collaborating Center for Reference and Research on Influenza , Beijing , People's Republic of China.,c Key Laboratory for Medical Virology, National Health Commission , Beijing , People's Republic of China
| | - Edward C Holmes
- i Marie Bashir Institute for Infectious Diseases and Biosecurity, Charles Perkins Centre, School of Life and Environmental Sciences and Sydney Medical School, The University of Sydney , Sydney , Australia
| | - George F Gao
- j Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences , Beijing , People's Republic of China.,k Center for Influenza Research and Early-Warning (CASCIRE), Chinese Academy of Sciences , Beijing , People's Republic of China.,l Chinese Center for Disease Control and Prevention (China CDC) , Beijing , People's Republic of China
| | - Dayan Wang
- a Chinese National Influenza Center, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention , Beijing , People's Republic of China.,b WHO Collaborating Center for Reference and Research on Influenza , Beijing , People's Republic of China.,c Key Laboratory for Medical Virology, National Health Commission , Beijing , People's Republic of China
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9
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Njifon HLM, Monamele CG, Vernet MA, Njankouo MR, Deweerdt L, Nono R, Kenmoe S, Mbacham W, Njouom R. Genetic diversity of influenza A(H3N2) viruses in Northern Cameroon during the 2014-2016 influenza seasons. J Med Virol 2019; 91:1400-1407. [PMID: 30866072 DOI: 10.1002/jmv.25456] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 02/05/2019] [Accepted: 02/06/2019] [Indexed: 12/11/2022]
Abstract
In Cameroon, genome characterization of influenza virus has been performed only in the Southern regions meanwhile genetic diversity of this virus varies with respect to locality. The Northern region characterized by a Sudan tropical climate might have distinct genetic characterization. This study aimed to better understand the genetic diversity of influenza A(H3N2) viruses circulating in Northern Cameroon. Sequences of three gene segments (hemagglutinin (HA), neuraminidase (NA) and matrix (M) genes) were obtained from 16 A(H3N2) virus strains collected during the 2014 to 2016 influenza seasons in Garoua. The HA gene segments were analysed with respect to reference strains while the NA and M gene was analysed for reported genetic markers of resistance to antivirals. Analysis of the HA sequences revealed that majority of the virus strains grouped together with the 2016-2017 vaccine strain (3C.2a-A/Hong Kong/4801/2014) while 3/5 (60%) of the 2015 viral strains grouped together with the 2015-2016 vaccine strain 3C.3a-A/Switzerland/9715293/2013. Within clade 3C.2a, Northern Cameroon sequences mostly grouped in sub-clade A3 (10/16). Analysis of the coding regions of the NA and M genes showed that none had genetic markers of resistance to neuraminidase inhibitors but all strains possessed the S31N substitution of resistance to amantadine. Due to some discrepancies observed in this region with respect to the Southern regions of Cameroon, there is necessity of including all regions within a country in the sentinel surveillance of influenza. These data will enable to track changes in influenza viruses in Cameroon.
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Affiliation(s)
- Hermann Landry Munshili Njifon
- National Influenza Centre, Centre Pasteur of Cameroon, Yaoundé, Cameroon, PO Box 1274, Yaoundé, Cameroon.,Centre Pasteur of Cameroon, Annex of Garoua, PO Box 921, Garoua, Cameroon.,Faculty of Science, University of Yaoundé 1, P.O Box 812, Yaoundé, Cameroon
| | - Chavely Gwladys Monamele
- National Influenza Centre, Centre Pasteur of Cameroon, Yaoundé, Cameroon, PO Box 1274, Yaoundé, Cameroon
| | - Marie-Astrid Vernet
- National Influenza Centre, Centre Pasteur of Cameroon, Yaoundé, Cameroon, PO Box 1274, Yaoundé, Cameroon
| | - Mohamadou Ripa Njankouo
- National Influenza Centre, Centre Pasteur of Cameroon, Yaoundé, Cameroon, PO Box 1274, Yaoundé, Cameroon
| | - Louis Deweerdt
- Centre Pasteur of Cameroon, Annex of Garoua, PO Box 921, Garoua, Cameroon
| | - Raphael Nono
- Centre Pasteur of Cameroon, Annex of Garoua, PO Box 921, Garoua, Cameroon
| | - Sebastien Kenmoe
- National Influenza Centre, Centre Pasteur of Cameroon, Yaoundé, Cameroon, PO Box 1274, Yaoundé, Cameroon
| | - Wilfred Mbacham
- Faculty of Science, University of Yaoundé 1, P.O Box 812, Yaoundé, Cameroon
| | - Richard Njouom
- National Influenza Centre, Centre Pasteur of Cameroon, Yaoundé, Cameroon, PO Box 1274, Yaoundé, Cameroon
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10
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Bakri M, Samuh M, Azzeh M. Molecular epidemiology survey and characterization of human influenza A viruses circulating among Palestinians in East Jerusalem and the West Bank in 2015. PLoS One 2019; 14:e0213290. [PMID: 30849093 PMCID: PMC6407757 DOI: 10.1371/journal.pone.0213290] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 02/18/2019] [Indexed: 11/19/2022] Open
Abstract
Frequent typing and molecular characterization of influenza A (IAV) strains are crucial for the identification of circulating subtypes and for the selection of the subtypes’ lineages to be included in the annually prepared vaccine cocktail. We investigated IAV sampled from an underrepresented population from Palestine. 200 nasopharyngeal aspirates (NPA) were collected between February and May of 2015 from Palestinians in East Jerusalem and the West Bank suffering from mild to severe symptoms of upper respiratory infections. NPA were screened for the presence of IAV using RT-PCR. Epidemiological data, hemagglutinin (HA) and neuraminidase (NA) gene sequences were analyzed in IAV positive samples. 50 samples tested positive for IAV; 48% of which were identified as A(H1N1)pdm09 and 52% as A(H3N2), respectively. Infection with A(H1N1)pdm09 occurred mainly in April, while A(H3N2) infections were mainly detected in March. Most IAV infections in 6-year-olds and below were attributed to subtype A(H3N2), while A(H1N1)pdm09 was responsible for most infections in adults above 18-year-olds. Analyses of HA and NA amino acid sequences revealed numerous substitutions. Thereafter, and based on the HA analysis, the Palestinian A(H1N1)pdm09 isolates fell into clade 6B, while the A(H3N2) isolates fell into clades 3C.2 and 3C.3, respectively. This study is significant in providing the first insight into the epidemiology and genetic properties of IAV circulating in Palestine. In contrast to international reports for the same season, A(H3N2) was not the dominant subtype as in northern hemisphere, nor was A(H1N1)pdm09 as in WHO reports for the Middle East, however genetic properties of Palestinian A(H3N2) and A(H1N1)pdm09 were in line with global isolates.
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Affiliation(s)
- Maysoon Bakri
- Virology Research Laboratory, Medical Research Center, Al-Quds University, Abu Dies-East Jerusalem, West Bank, Palestine
| | - Monjed Samuh
- Department of Applied Mathematics and Physics, Palestine Polytechnic University, Hebron, West Bank, Palestine
| | - Maysa Azzeh
- Virology Research Laboratory, Medical Research Center, Al-Quds University, Abu Dies-East Jerusalem, West Bank, Palestine
- * E-mail:
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11
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Molecular characterization of influenza A(H1N1)pdm09 in Cameroon during the 2014-2016 influenza seasons. PLoS One 2019; 14:e0210119. [PMID: 30640922 PMCID: PMC6331099 DOI: 10.1371/journal.pone.0210119] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 12/17/2018] [Indexed: 12/11/2022] Open
Abstract
In 2009, Influenza A(H1N1)pdm09 caused the first influenza pandemic of the 21st century with high mortality rates of about 284 500 deaths. This virus, however, continues to circulate as a seasonal influenza virus and to cause illness and deaths worldwide. In this study, we describe the genetic diversity of A(H1N1)pdm09 viruses collected between 2014 and 2016 in Cameroon. Three gene segments (HA, NA and M) of Cameroon strains were studied. The phylogenetic tree of the coding nucleotide sequences was generated by MEGA version 6.0 using a Maximum Likelihood method. The NA and M protein coding sequences were analyzed for the reported genetic markers of resistance against neuraminidase inhibitors and adamantanes, while predicted vaccine efficacy was estimated using the Pepitope method. Overall 39 strains were obtained. Phylogenetic analysis of the HA gene of influenza A(H1N1)pdm09 showed that Cameroon strains belonged to two major clades. The 2014 Cameroon sequences belonged to clade 6C while all sequences collected between 2015 and 2016 belonged to clade 6B. Majority of the samples had some mutations in the NA gene notably: I117M, N248D, and N369K while the amantadine-resistant M mutant, S31N, was found to be absent only in the two sequences collected in 2014. Overall, A/California/07/2009 vaccine strain showed a predicted vaccine efficacy of 24.55% to 35.77% against Cameroon A(H1N1)pdm09 strains circulating between 2014 and 2016. Our findings confirms the fast evolution of A(H1N1)pdm09 since its first introduction and highlights on the importance of influenza vaccine in reducing the burden caused by influenza in the community.
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12
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Monamele CG, Vernet MA, Njankouo MR, Kenmoe S, Schoenhals M, Yahaya AA, Anong DN, Akoachere JF, Njouom R. Genetic characterization of influenza B virus in Cameroon and high frequency of reassortant strains. J Med Virol 2018; 90:1848-1855. [PMID: 30036447 DOI: 10.1002/jmv.25273] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 07/05/2018] [Indexed: 11/06/2022]
Abstract
Influenza B is broadly divided into B/Victoria and B/Yamagata lineages based on its genetic and antigenic properties. We describe in this study the first report on genome characterization of type B influenza virus in the Cameroon National Influenza Center (NIC) between 2014 and 2017. Respiratory samples were collected as part of the influenza surveillance activity in the NIC. RNA products were tested for the presence of influenza using the CDC Influenza A/B typing panel. Thirty-five samples positive for influenza B were selected for sequencing three gene segments (HA, NA, and M) and phylogenetic trees were generated by MEGA version 6.0. Nucleotide phylogenetic analysis of the HA gene revealed the presence of three major clades among Cameroonian strains. All Victoria lineages grouped into B/Victoria clade 1A, while, Yamagata lineages grouped into Yamagata clade 2 (2014 strains) and Yamagata clade 3 (2015-2017). We observed a high frequency of reassortant viruses with Yamagata-like HA gene and Victoria-like NA gene (27.4%; 23/84). The results from this study confirm variations in the genome composition of type B influenza virus and emphasize on the relevance of molecular surveillance for spotting peculiar genetic variants of public health and clinical significance.
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Affiliation(s)
- Chavely Gwladys Monamele
- Virology Department, Centre Pasteur of Cameroon, Institute Pasteur International Network, Yaounde, Cameroon.,Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
| | - Marie-Astrid Vernet
- Virology Department, Centre Pasteur of Cameroon, Institute Pasteur International Network, Yaounde, Cameroon
| | - Mohamadou Ripa Njankouo
- Virology Department, Centre Pasteur of Cameroon, Institute Pasteur International Network, Yaounde, Cameroon
| | - Sebastien Kenmoe
- Virology Department, Centre Pasteur of Cameroon, Institute Pasteur International Network, Yaounde, Cameroon
| | - Matthieu Schoenhals
- Virology Department, Centre Pasteur of Cameroon, Institute Pasteur International Network, Yaounde, Cameroon
| | - Ali Ahmed Yahaya
- World Health Organization, Regional Office for Africa, Brazzaville, Congo
| | - Damian Nota Anong
- Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon.,Department of Biological Sciences, University of Bamenda, Bamenda, Cameroon
| | | | - Richard Njouom
- Virology Department, Centre Pasteur of Cameroon, Institute Pasteur International Network, Yaounde, Cameroon
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13
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Xu L, Jiang X, Zhu Y, Duan Y, Huang T, Huang Z, Liu C, Xu B, Xie Z. A Multiplex Asymmetric Reverse Transcription-PCR Assay Combined With an Electrochemical DNA Sensor for Simultaneously Detecting and Subtyping Influenza A Viruses. Front Microbiol 2018; 9:1405. [PMID: 30013525 PMCID: PMC6036258 DOI: 10.3389/fmicb.2018.01405] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 06/07/2018] [Indexed: 12/21/2022] Open
Abstract
The reliable and rapid detection of viral pathogens that cause respiratory infections provide physicians several advantages in treating patients and managing outbreaks. The Luminex respiratory virus panel (RVP) assay has been shown to be comparable to or superior to culture/direct fluorescent-antibody assays (DFAs) and nucleic acid tests that are used to diagnose respiratory viral infections. We developed a multiplex asymmetric reverse transcription (RT)-PCR assay that can simultaneously differentiate all influenza A virus epidemic subtypes. The amplified products were hybridized with an electrochemical DNA sensor, and the results were automatically acquired. The limits of detection (LoDs) of both the Luminex RVP assay and the multiplex RT-PCR-electrochemical DNA sensor were 101 TCID50 for H1N1 virus and 102 TCID50 for H3N2 virus. The specificity assessment of the multiplex RT-PCR-electrochemical DNA sensor showed no cross-reactivity among different influenza A subtypes or with other non-influenza respiratory viruses. In total, 3098 respiratory tract specimens collected from padiatric patients diagnosed with pneumonia were tested. More than half (43, 53.75%) of the specimens positive for influenza A viruses could not be further subtyped using the Luminex RVP assay. Among the remaining 15 specimens that were not subtyped, not degraded, and in sufficient amounts for the multiplex RT-PCR-electrochemical DNA sensor test, all (100%) were H3N2 positive. Therefore, the sensitivity of the Luminex RVP assay for influenza A virus was 46.25%, whereas the sensitivity of the multiplex RT-PCR-electrochemical DNA sensor for the clinical H1N1 and H3N2 specimens was 100%. The sensitivities of the multiplex RT-PCR-electrochemical DNA sensor for the avian H5N1, H5N6, H9N2, and H10N8 viruses were 100%, whereas that for H7N9 virus was 85.19%. We conclude that the multiplex RT-PCR-electrochemical DNA sensor is a reliable method for the rapid and accurate detection of highly variable influenza A viruses in respiratory infections with greater detection sensitivity than that of the Luminex xTAG assay. The high mutation rate of influenza A viruses, particularly H3N2 during the 2014 to 2016 epidemic seasons, has a strong impact on diagnosis. A study involving more positive specimens from all influenza A virus epidemic subtypes is required to fully assess the performance of the assay.
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Affiliation(s)
- Lili Xu
- Beijing Key Laboratory of Pediatric Respiratory Infection Diseases, Key Laboratory of Major Diseases in Children, Ministry of Education, National Clinical Research Center for Respiratory Diseases, National Key Discipline of Pediatrics (Capital Medical University), Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - Xiwen Jiang
- DAAN Gene Co., Ltd., Sun Yat-sen University, Guangzhou, China.,The Medicine and Biological Engineering Technology Research Center of the Ministry of Health, Guangzhou, China
| | - Yun Zhu
- Beijing Key Laboratory of Pediatric Respiratory Infection Diseases, Key Laboratory of Major Diseases in Children, Ministry of Education, National Clinical Research Center for Respiratory Diseases, National Key Discipline of Pediatrics (Capital Medical University), Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - Yali Duan
- Beijing Key Laboratory of Pediatric Respiratory Infection Diseases, Key Laboratory of Major Diseases in Children, Ministry of Education, National Clinical Research Center for Respiratory Diseases, National Key Discipline of Pediatrics (Capital Medical University), Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - Taosheng Huang
- DAAN Gene Co., Ltd., Sun Yat-sen University, Guangzhou, China.,The Medicine and Biological Engineering Technology Research Center of the Ministry of Health, Guangzhou, China
| | - Zhiwen Huang
- DAAN Gene Co., Ltd., Sun Yat-sen University, Guangzhou, China.,The Medicine and Biological Engineering Technology Research Center of the Ministry of Health, Guangzhou, China
| | - Chunyan Liu
- Beijing Key Laboratory of Pediatric Respiratory Infection Diseases, Key Laboratory of Major Diseases in Children, Ministry of Education, National Clinical Research Center for Respiratory Diseases, National Key Discipline of Pediatrics (Capital Medical University), Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - Baoping Xu
- National Clinical Research Center for Respiratory Diseases, Department of Respiratory, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - Zhengde Xie
- Beijing Key Laboratory of Pediatric Respiratory Infection Diseases, Key Laboratory of Major Diseases in Children, Ministry of Education, National Clinical Research Center for Respiratory Diseases, National Key Discipline of Pediatrics (Capital Medical University), Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
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