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Ayuso García B, Marchan A, Arrieta Ortubay E, Castillo Maza C, Romay Lema E, Lalueza A, Lumbreras C. In-hospital incidence of and risk factors for influenza-associated respiratory failure. Eur J Clin Invest 2022; 52:e13858. [PMID: 35997028 DOI: 10.1111/eci.13858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 08/14/2022] [Accepted: 08/15/2022] [Indexed: 11/29/2022]
Abstract
BACKGROUND Respiratory failure (RF) is the most important complication of influenza virus infection. Its definition and incidence are heterogeneous in the literature. METHODS This systematic review and meta-analysis aim to determine the incidence of and risk factors for RF in patients hospitalized with influenza. Electronic databases were searched for articles on RF in patients hospitalized for influenza infection up to December 2021 regardless of their geographical location. Observational and experimental studies were considered for inclusion, excluding case series. The Newcastle-Ottawa and Johanna Briggs scales were used for quality assessment. A random-effects meta-analysis was performed, followed by subgroup analyses according to, among others, presence/absence of pneumonia, RF definition, serotype and time period. PRISMA guidelines were followed for this review. RESULTS Thirty-six studies were finally included in the meta-analysis. Overall, RF incidence was 24% (range 5%-85%, 95% confidence interval [95CI] 19%-31%). Significantly higher incidences of RF were found in patients with pneumonia (42%, 95CI 28%-57%, p = .006), when RF was defined as hypoxemia (58%, 95CI 31%-81%, p < .001), and during the 2009 pandemic (25%, 95CI 16%-36%) and postpandemic period (23%, 95CI 15%-34%, p = .01). No differences were found between human influenza serotypes. Assessment of risk factors associated with the development of RF was not possible due to their inconsistent and heterogeneous reporting. CONCLUSION Respiratory failure is frequent in hospitalized influenza patients, especially in patients with pneumonia and since the 2009 pandemic, although its definition and reporting widely vary in the literature. This complicates its characterization and comparison between cohorts and with other respiratory viruses.
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Affiliation(s)
- Blanca Ayuso García
- Department of Internal Medicine, University Hospital 12 de Octubre, Madrid, Spain
| | - Alvaro Marchan
- Department of Internal Medicine, University Hospital 12 de Octubre, Madrid, Spain
| | | | | | - Eva Romay Lema
- Infectious Diseases Unit, University Hospital Lucus Augusti, Lugo, Spain
| | - Antonio Lalueza
- Department of Internal Medicine, University Hospital 12 de Octubre, Madrid, Spain.,Department of Medicine, School of Medicine, Complutense University, Madrid, Spain.,Research Institute of Hospital 12 de Octubre (i+12), Madrid, Spain
| | - Carlos Lumbreras
- Department of Internal Medicine, University Hospital 12 de Octubre, Madrid, Spain.,Department of Medicine, School of Medicine, Complutense University, Madrid, Spain.,Research Institute of Hospital 12 de Octubre (i+12), Madrid, Spain.,Infectious Diseases Unit, University Hospital 12 de Octubre, Madrid, Spain
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2
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Liu T, Wang Y, Tan TJC, Wu NC, Brooke CB. The evolutionary potential of influenza A virus hemagglutinin is highly constrained by epistatic interactions with neuraminidase. Cell Host Microbe 2022; 30:1363-1369.e4. [PMID: 36150395 PMCID: PMC9588755 DOI: 10.1016/j.chom.2022.09.003] [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: 05/24/2022] [Revised: 07/27/2022] [Accepted: 09/02/2022] [Indexed: 11/03/2022]
Abstract
Antigenic evolution of the influenza A virus (IAV) hemagglutinin (HA) gene limits efforts to effectively control the spread of the virus in the population. Efforts to understand the mechanisms governing HA antigenic evolution typically examine the HA gene in isolation. This can ignore the importance of balancing HA receptor binding activities with the receptor-destroying activities of the viral neuraminidase (NA) to maintain viral fitness. We hypothesize that the need to maintain functional balance with NA significantly constrains the evolutionary potential of the HA. We use deep mutational scanning and show that variation in NA activity significantly reshapes the HA fitness landscape by modulating the overall mutational robustness of HA. Consistent with this, we observe that different NA backgrounds support the emergence of distinct repertoires of HA escape variants under neutralizing antibody pressure. Our results reveal a critical role for intersegment epistasis in influencing the evolutionary potential of the HA gene.
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Affiliation(s)
- Tongyu Liu
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Yiquan Wang
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Timothy J C Tan
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Nicholas C Wu
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Carle Illinois College of Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
| | - Christopher B Brooke
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
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3
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Lee YM, Kim SW, Kwack WG. Tracheitis Caused by Coinfection with Cytomegalovirus and Herpes Simplex Virus. Medicina (B Aires) 2021; 57:medicina57111162. [PMID: 34833380 PMCID: PMC8624308 DOI: 10.3390/medicina57111162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 10/18/2021] [Accepted: 10/25/2021] [Indexed: 11/29/2022] Open
Abstract
Clinically significant isolated viral tracheitis is scarce in adults, and upper airway obstruction caused by viral tracheitis is even more infrequent. A 74-year-old woman, who was administered low-dose steroids for two months for chronic obstructive pulmonary disease (COPD), developed dyspnea with stridor and required mechanical ventilation for respiratory failure. Chest computed tomography showed a diffuse tracheal wall thickening with luminal narrowing and peribronchial consolidation in the right upper lobe. Bronchoscopy revealed a proximal tracheal narrowing with multiple ulcerations of the tracheal mucosa surrounded by an erythematous margin. Pathologic examinations of the tracheal mucosal tissue, including immunohistochemistry, revealed a cytomegalovirus (CMV) and herpes simplex virus (HSV) infection. Furthermore, the bronchial alveolar lavage fluid was positive on the CMV real-time polymerase chain reaction. The patient was treated with intravenous ganciclovir for 44 days. The follow-up bronchoscopy 49 days after the initiation of ganciclovir revealed improved multiple ulcerations with scars. We report a rare case of tracheitis caused by coinfection with CMV and HSV in a patient with COPD who had been taking low-dose steroids for months. The case showed that CMV and HSV are potential causes of serious tracheitis and respiratory failure.
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Affiliation(s)
- Yu-Mi Lee
- Division of Infectious Diseases, Department of Internal Medicine, Kyung Hee University Hospital, Kyung Hee University School of Medicine, Seoul 02447, Korea;
| | - So-Woon Kim
- Department of Pathology, Kyung Hee University Hospital, Kyung Hee University School of Medicine, Seoul 02447, Korea;
| | - Won-Gun Kwack
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Kyung Hee University Hospital, Seoul 02447, Korea
- Correspondence: ; Tel.: +82-2-958-8194
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4
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Danilenko AV, Kolosova NP, Shvalov AN, Ilyicheva TN, Svyatchenko SV, Durymanov AG, Bulanovich JA, Goncharova NI, Susloparov IM, Marchenko VY, Tregubchak TV, Gavrilova EV, Maksyutov RA, Ryzhikov AB. Evaluation of HA-D222G/N polymorphism using targeted NGS analysis in A(H1N1)pdm09 influenza virus in Russia in 2018-2019. PLoS One 2021; 16:e0251019. [PMID: 33914831 PMCID: PMC8084186 DOI: 10.1371/journal.pone.0251019] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 04/19/2021] [Indexed: 02/07/2023] Open
Abstract
Outbreaks of influenza, which is a contagious respiratory disease, occur throughout the world annually, affecting millions of people with many fatal cases. The D222G/N mutations in the hemagglutinin (HA) gene of A(H1N1)pdm09 are associated with severe and fatal human influenza cases. These mutations lead to increased virus replication in the lower respiratory tract (LRT) and may result in life-threatening pneumonia. Targeted NGS analysis revealed the presence of mutations in major and minor variants in 57% of fatal cases, with the proportion of viral variants with mutations varying from 1% to 98% in each individual sample in the epidemic season 2018-2019 in Russia. Co-occurrence of the mutations D222G and D222N was detected in a substantial number of the studied fatal cases (41%). The D222G/N mutations were detected at a low frequency (less than 1%) in the rest of the studied samples from fatal and nonfatal cases of influenza. The presence of HA D222Y/V/A mutations was detected in a few fatal cases. The high rate of occurrence of HA D222G/N mutations in A(H1N1)pdm09 viruses, their increased ability to replicate in the LRT and their association with fatal outcomes points to the importance of monitoring the mutations in circulating A(H1N1)pdm09 viruses for the evaluation of their epidemiological significance and for the consideration of disease prevention and treatment options.
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Affiliation(s)
- Alexey V. Danilenko
- Vector State Research Center of Virology and Biotechnology, Koltsovo, Novosibirsk Region, Russia
| | - Natalia P. Kolosova
- Vector State Research Center of Virology and Biotechnology, Koltsovo, Novosibirsk Region, Russia
| | - Alexander N. Shvalov
- Vector State Research Center of Virology and Biotechnology, Koltsovo, Novosibirsk Region, Russia
| | - Tatyana N. Ilyicheva
- Vector State Research Center of Virology and Biotechnology, Koltsovo, Novosibirsk Region, Russia
- Novosibirsk State University, Novosibirsk, Russia
| | - Svetlana V. Svyatchenko
- Vector State Research Center of Virology and Biotechnology, Koltsovo, Novosibirsk Region, Russia
| | - Alexander G. Durymanov
- Vector State Research Center of Virology and Biotechnology, Koltsovo, Novosibirsk Region, Russia
| | - Julia A. Bulanovich
- Vector State Research Center of Virology and Biotechnology, Koltsovo, Novosibirsk Region, Russia
| | - Natalia I. Goncharova
- Vector State Research Center of Virology and Biotechnology, Koltsovo, Novosibirsk Region, Russia
| | - Ivan M. Susloparov
- Vector State Research Center of Virology and Biotechnology, Koltsovo, Novosibirsk Region, Russia
| | - Vasiliy Y. Marchenko
- Vector State Research Center of Virology and Biotechnology, Koltsovo, Novosibirsk Region, Russia
| | - Tatyana V. Tregubchak
- Vector State Research Center of Virology and Biotechnology, Koltsovo, Novosibirsk Region, Russia
| | - Elena V. Gavrilova
- Vector State Research Center of Virology and Biotechnology, Koltsovo, Novosibirsk Region, Russia
| | - Rinat A. Maksyutov
- Vector State Research Center of Virology and Biotechnology, Koltsovo, Novosibirsk Region, Russia
| | - Alexander B. Ryzhikov
- Vector State Research Center of Virology and Biotechnology, Koltsovo, Novosibirsk Region, Russia
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5
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Update on childhood and adult infectious tracheitis. Med Mal Infect 2017; 47:443-452. [PMID: 28757125 PMCID: PMC7125831 DOI: 10.1016/j.medmal.2017.06.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2016] [Revised: 07/24/2016] [Accepted: 06/19/2017] [Indexed: 12/11/2022]
Abstract
The trachea is a pivotal organ of the respiratory tract. Rather than a genuine anatomic border, it acts as a crossroad in all respiratory infectious processes. Even though not strictly limited to the trachea, infections such as laryngotracheitis and tracheobronchitis are frequently diagnosed in children, in particular during the winter season. Infectious tracheitis etiologies are diverse and the distinction between viral and bacterial origins, albeit difficult, remains relevant considering the substantial differences in terms of gravity and therapeutic management. This literature review summarizes the microbiological and clinical aspects of community-acquired and nosocomial tracheitis in adults and children, as well as the adequate diagnostic and therapeutic approaches. It also highlights the emergence of fungal tracheitis in immunocompromised patients, of ventilator-associated tracheitis in intensive care medicine, and beyond all that the potential short and long-term consequences of tracheitis.
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6
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Moncla LH, Zhong G, Nelson CW, Dinis JM, Mutschler J, Hughes AL, Watanabe T, Kawaoka Y, Friedrich TC. Selective Bottlenecks Shape Evolutionary Pathways Taken during Mammalian Adaptation of a 1918-like Avian Influenza Virus. Cell Host Microbe 2016; 19:169-80. [PMID: 26867176 PMCID: PMC4761429 DOI: 10.1016/j.chom.2016.01.011] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 10/26/2015] [Accepted: 01/25/2016] [Indexed: 01/14/2023]
Abstract
Avian influenza virus reassortants resembling the 1918 human pandemic virus can become transmissible among mammals by acquiring mutations in hemagglutinin (HA) and polymerase. Using the ferret model, we trace the evolutionary pathway by which an avian-like virus evolves the capacity for mammalian replication and airborne transmission. During initial infection, within-host HA diversity increased drastically. Then, airborne transmission fixed two polymerase mutations that do not confer a detectable replication advantage. In later transmissions, selection fixed advantageous HA1 variants. Transmission initially involved a "loose" bottleneck, which became strongly selective after additional HA mutations emerged. The stringency and evolutionary forces governing between-host bottlenecks may therefore change throughout host adaptation. Mutations occurred in multiple combinations in transmitted viruses, suggesting that mammalian transmissibility can evolve through multiple genetic pathways despite phenotypic constraints. Our data provide a glimpse into avian influenza virus adaptation in mammals, with broad implications for surveillance on potentially zoonotic viruses.
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Affiliation(s)
- Louise H Moncla
- Department of Pathobiological Sciences, University of Wisconsin School of Veterinary Medicine, Madison, WI 53706, USA; Wisconsin National Primate Research Center, Madison, WI 53715, USA
| | - Gongxun Zhong
- Department of Pathobiological Sciences, University of Wisconsin School of Veterinary Medicine, Madison, WI 53706, USA
| | - Chase W Nelson
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Jorge M Dinis
- Department of Pathobiological Sciences, University of Wisconsin School of Veterinary Medicine, Madison, WI 53706, USA; Wisconsin National Primate Research Center, Madison, WI 53715, USA
| | - James Mutschler
- Department of Pathobiological Sciences, University of Wisconsin School of Veterinary Medicine, Madison, WI 53706, USA; Wisconsin National Primate Research Center, Madison, WI 53715, USA
| | - Austin L Hughes
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Tokiko Watanabe
- Department of Pathobiological Sciences, University of Wisconsin School of Veterinary Medicine, Madison, WI 53706, USA; Division of Virology, Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
| | - Yoshihiro Kawaoka
- Department of Pathobiological Sciences, University of Wisconsin School of Veterinary Medicine, Madison, WI 53706, USA; Division of Virology, Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan.
| | - Thomas C Friedrich
- Department of Pathobiological Sciences, University of Wisconsin School of Veterinary Medicine, Madison, WI 53706, USA; Wisconsin National Primate Research Center, Madison, WI 53715, USA.
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7
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Krasnoslobodtsev KG, Lvov DK, Alkhovsky SV, Burtseva EI, Fedyakina IT, Kolobukhina LV, Kirillova ES, Trushakova SV, Oskerko TA, Shchelkanov MY, Deryabin PG. Amino acid polymorphism at residue 222 of the receptor-binding site of the hemagglutinin of the pandemic influenza A(H1N1)pdm09 from patients 166 with lethal virus pneumonia in 2012-2014. Vopr Virusol 2016; 61:166-171. [PMID: 36494964 DOI: 10.18821/0507-4088-2016-61-4-166-171] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Indexed: 12/13/2022]
Abstract
Survey data from autopsy specimens from patients who died from pneumonia caused by the influenza A(H1N1) pdm09 in 2012-2014 and mutant forms of influenza virus in these patients (position 222 in the receptor-binding region of hemagglutinin) were presented. In total, according to aggregate data, obtained with three different methods (sequencing, next-generation sequencing (NGS), virus isolation) mutant viruses were detected in 17 (41%) from 41 patients. The proportion of the mutant forms in viral populations ranged from 1% to 69.2%. The most frequent mixture was the wild type (D222) and mutant (D222G), with proportion of mutant type ranged from 3.3% to 69.2% in the viral population. Mutation D222N (from 1.1% to 5.5%) was found rarely. Composition of the viral population from one patient is extremely heterogeneous: in left lung there was only wild type D222, meantime in right lung - mixture of mutant forms 222D/N/G (65.4/32.5/1.1%), in trachea - mixture 222D/G/Y/A (61.8/35.6/1.2/1.4%, respectively), and in bronchi compound of 222D/G/N/A (64.3/33.7/1/1%, respectively) were detected. The obtained data indicate that the process of adaptation of the virus in the lower respiratory tract is coupled with the appearance of different virus variants with mutations in the receptor-binding region. Mutant forms of the virus are observed in the lower respiratory tract of the majority of patients with lethal viral pneumonia. However, if they are a minor part of the population, they cannot be detected by the method of conventional sequencing. They can be identified using the NGS methods.
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Affiliation(s)
- K G Krasnoslobodtsev
- «Federal Research Centre of Epidemilogy and Microbiology named after the honorary academician N.F. Gamaleya»
| | - D K Lvov
- «Federal Research Centre of Epidemilogy and Microbiology named after the honorary academician N.F. Gamaleya»
| | - S V Alkhovsky
- «Federal Research Centre of Epidemilogy and Microbiology named after the honorary academician N.F. Gamaleya»
| | - E I Burtseva
- «Federal Research Centre of Epidemilogy and Microbiology named after the honorary academician N.F. Gamaleya»
| | - I T Fedyakina
- «Federal Research Centre of Epidemilogy and Microbiology named after the honorary academician N.F. Gamaleya»
| | - L V Kolobukhina
- «Federal Research Centre of Epidemilogy and Microbiology named after the honorary academician N.F. Gamaleya»
| | - E S Kirillova
- «Federal Research Centre of Epidemilogy and Microbiology named after the honorary academician N.F. Gamaleya»
| | - S V Trushakova
- «Federal Research Centre of Epidemilogy and Microbiology named after the honorary academician N.F. Gamaleya»
| | - T A Oskerko
- «Federal Research Centre of Epidemilogy and Microbiology named after the honorary academician N.F. Gamaleya»
| | - M Y Shchelkanov
- «Federal Research Centre of Epidemilogy and Microbiology named after the honorary academician N.F. Gamaleya»
| | - P G Deryabin
- «Federal Research Centre of Epidemilogy and Microbiology named after the honorary academician N.F. Gamaleya»
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Iovine NM, Morris JG, Fredenburg K, Rand K, Alnuaimat H, Lipori G, Brew J, Lednicky JA. Severity of influenza A(H1N1) illness and emergence of D225G variant, 2013-14 influenza season, Florida, USA. Emerg Infect Dis 2015; 21:664-7. [PMID: 25811540 PMCID: PMC4378462 DOI: 10.3201/eid2104.141375] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Despite a regional decline in influenza A(H1N1)pdm09 virus infections during 2013-14, cases at a Florida hospital were more severe than those during 2009-10. Examined strains had a hemagglutinin polymorphism associated with enhanced binding to lower respiratory tract receptors. Genetic changes in this virus must be monitored to predict the effect of future pandemic viruses.
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Equine and Canine Influenza H3N8 Viruses Show Minimal Biological Differences Despite Phylogenetic Divergence. J Virol 2015; 89:6860-73. [PMID: 25903329 DOI: 10.1128/jvi.00521-15] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 04/14/2015] [Indexed: 12/14/2022] Open
Abstract
UNLABELLED The A/H3N8 canine influenza virus (CIV) emerged from A/H3N8 equine influenza virus (EIV) around the year 2000 through the transfer of a single virus from horses to dogs. We defined and compared the biological properties of EIV and CIV by examining their genetic variation, infection, and growth in different cell cultures, receptor specificity, hemagglutinin (HA) cleavage, and infection and growth in horse and dog tracheal explant cultures. Comparison of sequences of viruses from horses and dogs revealed mutations that may be linked to host adaptation and tropism. We prepared infectious clones of representative EIV and CIV strains that were similar to the consensus sequences of viruses from each host. The rescued viruses, including HA and neuraminidase (NA) double reassortants, exhibited similar degrees of long-term growth in MDCK cells. Different host cells showed various levels of susceptibility to infection, but no differences in infectivity were seen when comparing viruses. All viruses preferred α2-3- over α2-6-linked sialic acids for infections, and glycan microarray analysis showed that EIV and CIV HA-Fc fusion proteins bound only to α2-3-linked sialic acids. Cleavage assays showed that EIV and CIV HA proteins required trypsin for efficient cleavage, and no differences in cleavage efficiency were seen. Inoculation of the viruses into tracheal explants revealed similar levels of infection and replication by each virus in dog trachea, although EIV was more infectious in horse trachea than CIV. IMPORTANCE Influenza A viruses can cross species barriers and cause severe disease in their new hosts. Infections with highly pathogenic avian H5N1 virus and, more recently, avian H7N9 virus have resulted in high rates of lethality in humans. Unfortunately, our current understanding of how influenza viruses jump species barriers is limited. Our aim was to provide an overview and biological characterization of H3N8 equine and canine influenza viruses using various experimental approaches, since the canine virus emerged from horses approximately 15 years ago. We showed that although there were numerous genetic differences between the equine and canine viruses, this variation did not result in dramatic biological differences between the viruses from the two hosts, and the viruses appeared phenotypically equivalent in most assays we conducted. These findings suggest that the cross-species transmission and adaptation of influenza viruses may be mediated by subtle changes in virus biology.
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Hemagglutinin mutation D222N of the 2009 pandemic H1N1 influenza virus alters receptor specificity without affecting virulence in mice. Virus Res 2014; 189:79-86. [DOI: 10.1016/j.virusres.2014.05.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2013] [Revised: 04/12/2014] [Accepted: 05/01/2014] [Indexed: 12/25/2022]
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11
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Yöntem Y, Ilker D, Yeşim O, Ayşen T, Gülcihan O, Özgür C, Meral AC, Burçak TG, Bengü D, Esin A, Selim B, Canan V. Analysis of fatal cases of pandemic influenza A (H1N1) virus infections in pediatric patients with leukemia. Pediatr Hematol Oncol 2013; 30:437-44. [PMID: 23697998 DOI: 10.3109/08880018.2013.796025] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Pandemic influenza A/H1N1/2009 virus usually causes mild illness in healthy children. Chronic medical conditions are recognized as increasing the risk for complications of influenza virus infection. Although most studies including children with acute leukemia and H1N1 virus have reported no deaths, some anectodal reports with low patient numbers have reported mortality rates as high as 28.5%. Here, we report patients with leukemia and H1N1 virus and review the literature. METHODS Medical records of all children with leukemia and H1N1 virus in our institution were reviewed for demographic, clinical, and laboratory data. We also carried out a systematic review of the English-language literature. Among the 24 articles found, only patients with leukemia and pandemic H1N1 infections were reviewed by two independent reviewers. RESULTS Eight of 98 children who received chemotherapy for leukemia were diagnosed with pandemic H1N1 infection. One developed pneumonia and acute respiratory distress syndrome (ARDS) and died. Another one developed hemophagocytic lymphohistiocytosis (HLH) and died due to secondary infection during the 6th week of treatment for HLH. In our study, 2 of 8 patients had a fatal course (25%), compared with an overall mortality of 2.5% in the studies retrieved from PubMed (6/232). CONCLUSION Pandemic H1N1 influenza virus caused mortality in patients with ARDS or HLH; an unexpected finding for pandemic H1N1 (2009) influenza virus. Thus, for children with leukemia and infected with H1N1 virus, short- and long-term complications should be kept in mind during evaluation.
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Affiliation(s)
- Yaman Yöntem
- Division of Pediatric Hematology, Dr. Behçet Uz Children's Hospital, İzmir, Turkey.
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