scholarly journals Nucleic acid-based detection of influenza A virus subtypes H7 and N9 with a special emphasis on the avian H7N9 virus

2014 ◽  
Vol 19 (10) ◽  
Author(s):  
D Kalthoff ◽  
J Bogs ◽  
T Harder ◽  
C Grund ◽  
A Pohlmann ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Influenza A ◽  
Animal Experiments ◽  
Simultaneous Detection ◽  
High Sensitivity ◽  
Epidemiological Studies ◽  
Severe Illness ◽  
The Novel ◽  
H7n9 Virus ◽  
Diagnostic Approaches

In 2013, a novel influenza A virus of subtype H7N9 was transmitted from avian sources to humans in China, causing severe illness and substantial mortality. Rapid and sensitive diagnostic approaches are the basis of epidemiological studies and of utmost importance for the detection of infected humans and animals. We developed various quantitative reverse transcriptase PCR (RT-qPCR) assays for (i) the generic detection of the haemagglutinin (HA) gene of H7 viruses or the neuraminidase (NA) gene of N9 viruses, and (ii) the specific detection of HA and NA of the novel avian H7N9/2013 virus. The sensitivity of the newly developed assays was compared with previously published PCRs, and the specificity of all RT-qPCRs was examined using a panel of 42 different H7 and 16 different N9 isolates. Furthermore, we analysed the performance of the RT-qPCR assays with dilution series and diagnostic samples obtained from animal experiments. Our study provides a comprehensive set of RT-qPCR assays for the reliable detection of the novel avian H7N9 virus, with high sensitivity and improved and tailored specificity values compared with published assays. Finally, we also present data about the robustness of a duplex assay for the simultaneous detection of HA and NA of the avian influenza H7N9/2013 virus.

scholarly journals Molecular Detection of Human H7N9 Influenza A Virus Causing Outbreaks in China

2013 ◽  
Vol 59 (7) ◽  
pp. 1062-1067 ◽  
Author(s):  
Chloe KS Wong ◽  
Huachen Zhu ◽  
Olive TW Li ◽  
Yin Hung C Leung ◽  
Michael CW Chan ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Rapid Detection ◽  
Influenza A ◽  
Negative Control ◽  
The Novel ◽  
H7n9 Virus ◽  
Influenza A Viruses ◽  
Reverse Transcription Pcr ◽  
Molecular Tests ◽  
Negative Controls

BACKGROUND A novel subtype of influenza A virus (H7N9) was recently identified in humans. The virus is a reassortant of avian viruses, but these human isolates contain mutations [hemagglutinin (HA) Q226L and PB2 E627K] that might make it easier for the virus to adapt to mammalian hosts. Molecular tests for rapid detection of this virus are urgently needed. METHODS We developed a 1-step quantitative real-time reverse-transcription PCR assay to detect the novel human H7N9 virus. The primer set was specific to the hemagglutinin (HA) gene of the H7N9 viruses currently causing the outbreak in China and had mismatches to all previously known avian or mammalian H7 HA sequences. In addition, the assay was evaluated using influenza A viruses of various genetic BACKGROUNDs and other negative controls. RESULTS The detection limit of the assay was approximately 0.04 TCID50 (median tissue culture infective dose) per reaction. The assay specificity was high and all negative control samples, including 8 H7 viruses not closely related to the human H7N9 virus, tested negative. CONCLUSIONS The established assay allows rapid detection of the novel human H7N9 virus, thereby allowing better pandemic preparedness.

Influenza A/B virus detection and influenza A virus subtyping with emphasis on the novel H7N9 virus by using multiplex real-time RT-PCR

2014 ◽  
Vol 208 ◽  
pp. 41-46 ◽  
Author(s):  
Rei-Lin Kuo ◽  
Shu-Li Yang ◽  
Yi-Chun Liu ◽  
Lu-Ting Chen ◽  
Chee-Keng Mok ◽  
...  
Keyword(s):  
Real Time ◽  
Influenza A Virus ◽  
Influenza A ◽  
Virus Detection ◽  
The Novel ◽  
H7n9 Virus ◽  
Rt Pcr ◽  
B Virus

An Update on the H7N9 Strain of the Influenza A Virus

2013 ◽  
Vol 2 (3) ◽  
pp. 59-66
Author(s):  
Dimitrios Vlachakis ◽  
Argiro Karozou ◽  
Spyridon Champeris Tsaniras ◽  
Sophia Kossida
Keyword(s):  
Influenza A Virus ◽  
Influenza A ◽  
World Wide ◽  
Current Knowledge ◽  
H7n9 Virus ◽  
Pandemic Threat ◽  
H7n9 Influenza ◽  
Pharmacological Target ◽  
Informed Opinion ◽  
Public Concerns

Currently, humanity lives in the verge of a world-wide epidemic of the H7N9 influenza A virus. This strain has turned out to be very virulent for humans and there have been many reported casualties already in several places around the globe. Concordantly, not much is known for the H7N9 strain. Herein, the authors intend to establish a modest database of current knowledge and informed opinion in different key areas of the H7N9 virus. The source of the virus, its infection routes and mutations remain unclear. Results of several recent studies will be further analyzed including clinical, virological and histopathological manifestations of H7N9, diagnosis modes and viral transmissibility. Treatment, vaccination and public concerns about a pandemic threat will be discussed as well. The present work is expected to act as an updated world reference for the H7N9 influenza A strain. Moreover, modes for tackling H7N9 will be proposed, focusing on RNA polymerase for further investigation as a potential pharmacological target. Hence, invaluable conclusions may be drawn that will lead to insights in the fight against the most recent and rather lethal H7N9 strain.

scholarly journals An overview of the characteristics of the novel avian influenza A H7N9 virus in humans

2015 ◽  
Vol 6 ◽  
Author(s):  
Kei-Xian Tan ◽  
Sabrina A. Jacob ◽  
Kok-Gan Chan ◽  
Learn-Han Lee
Keyword(s):  
Avian Influenza ◽  
Influenza A ◽  
The Novel ◽  
H7n9 Virus

scholarly journals Influenza Virus A/Anhui/1/2013 (H7N9) Replicates Efficiently in the Upper and Lower Respiratory Tracts of Cynomolgus Macaques

mBio ◽  
2014 ◽  
Vol 5 (4) ◽  
Author(s):  
Emmie de Wit ◽  
Angela L. Rasmussen ◽  
Friederike Feldmann ◽  
Trenton Bushmaker ◽  
Cynthia Martellaro ◽  
...  
Keyword(s):  
Gene Expression ◽  
Influenza Virus ◽  
Respiratory Tract ◽  
Influenza A Virus ◽  
Influenza A ◽  
Clinical Aspects ◽  
Polymorphonuclear Cells ◽  
H7n9 Virus ◽  
Cynomolgus Macaques ◽  
H7n9 Infection

ABSTRACT In March 2013, three fatal human cases of infection with influenza A virus (H7N9) were reported in China. Since then, human cases have been accumulating. Given the public health importance of this virus, we performed a pathogenicity study of the H7N9 virus in the cynomolgus macaque model, focusing on clinical aspects of disease, radiographic, histological, and gene expression profile changes in the upper and lower respiratory tracts, and changes in systemic cytokine and chemokine profiles during infection. Cynomolgus macaques developed transient, mild to severe disease with radiographic evidence of pulmonary infiltration. Virus replicated in the upper as well as lower respiratory tract, with sustained replication in the upper respiratory tract until the end of the experiment at 6 days after inoculation. Virus shedding occurred mainly via the throat. Histopathological changes in the lungs were similar to those observed in humans, albeit less severe, with diffuse alveolar damage, infiltration of polymorphonuclear cells, formation of hyaline membranes, pneumocyte hyperplasia, and fibroproliferative changes. Analysis of gene expression profiles in lung lesions identified pathways involved in tissue damage during H7N9 infection as well as leads for development of therapeutics targeting host responses rather than virus replication. Overall, H7N9 infection was not as severe in cynomolgus macaques as in humans, supporting the possible role of underlying medical complications in disease severity as discussed for human H7N9 infection (H. N. Gao et al., N. Engl. J. Med. 368:2277–2285, 2013, doi:10.1056/NEJMoa1305584). IMPORTANCE Influenza A virus H7N9 emerged early in 2013, and human cases have continued to emerge since then. Although H7N9 virus-induced disease in humans is often very severe and even lethal, the majority of reported H7N9 cases occurred in older people and people with underlying medical conditions. To better understand the pathogenicity of this virus, healthy cynomolgus macaques were inoculated with influenza A virus H7N9. Cynomolgus macaques were used as a model because the receptor distribution for H7N9 virus in macaques was recently shown to be more similar to that in humans than that of other frequently used animal models. From comparison with previous studies, we conclude that the emerging H7N9 influenza virus was more pathogenic in cynomolgus macaques than seasonal influenza A viruses and most isolates of the pandemic H1N1 virus but less pathogenic than the 1918 Spanish influenza virus or highly pathogenic avian influenza (HPAI) H5N1 virus.

scholarly journals Inactivation of the novel avian influenza A (H7N9) virus under physical conditions or chemical agents treatment

2013 ◽  
Vol 10 (1) ◽  
pp. 289 ◽  
Author(s):  
Shumei Zou ◽  
Junfeng Guo ◽  
Rongbao Gao ◽  
Libo Dong ◽  
Jianfang Zhou ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Influenza A ◽  
The Novel ◽  
H7n9 Virus ◽  
Physical Conditions ◽  
Chemical Agents

scholarly journals Monoclonal Antibody Kit for Identification of the Novel 2009 H1N1 Influenza A Virus

2010 ◽  
Vol 48 (8) ◽  
pp. 2677-2682 ◽  
Author(s):  
A. D. Higgins ◽  
C. J. Shaw ◽  
J. G. Johnson ◽  
A. Navarro ◽  
N. A. Chapman ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Influenza A Virus ◽  
Influenza A ◽  
H1n1 Influenza ◽  
The Novel ◽  
2009 H1n1
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