title: Detection of avian influenza A/H7N9/2013 virus by real-time reverse transcription-polymerase chain reaction.
abstract: The first case of avian influenza A/H7N9 infection was reported in Shanghai in mid-February, 2013; by May 1, 2013, it had infected 127 people and caused 26 deaths in 10 provinces in China. Therefore, it is important to obtain reliable epidemiological data on the spread of this new infectious agent, a need that may be best met by the development of novel molecular methods. Here, a new method was described for the detection of avian influenza A/H7N9 using real-time reverse transcription-polymerase chain reaction (rRT-PCR). Using serial dilutions of avian influenza A H7N9 cultures, the detection limit of the assay was determined to be approximately 3.2×10(-4) HAUs (hemagglutination units) for the H7 gene and 6.4×10(-4) HAUs for N9 gene. In tests of serial dilutions of in vitro-transcribed avian influenza A H7 and N9 gene RNA, positive results were obtained for target RNA containing at least three copies of the H7 gene and six copies of the N9 gene. Thirteen throat swabs from H7N9 patients were tested; all tested positive in the assay. Specificity was evaluated by testing 18 other subtypes of influenza viruses; all tested negative. A total of 180 throat swabs from patients infected with influenza virus, including 60 from patients infected with seasonal influenza A/H1N1 virus, 60 from patients infected with pandemic influenza A/H1N1/2009 virus, 30 from patients infected with seasonal influenza A/H3N2 virus and 30 from patients infected with influenza B virus, were also tested; all tested negative.
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Dongdajie Road 20, Beijing 100071, China.
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Kang
authors.affiliation: CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, No. 1 Beichen West Road, Beijing, Chaoyang District, 100101, China.
authors.forename: Weili
authors.initials: W
authors.lastname: Wu
authors.affiliation: National Institutes for Food and Drug Control, Beijing 100050, China.
authors.forename: Chuntao
authors.initials: C
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Dongdajie Road 20, Beijing 100071, China; Beijing BGI-GBI Biotech Co., Ltd., Beijing 101300, China.
authors.forename: Licheng
authors.initials: L
authors.lastname: Liu
authors.affiliation: Beijing BGI-GBI Biotech Co., Ltd., Beijing 101300, China.
authors.forename: Huahua
authors.initials: H
authors.lastname: Feng
authors.affiliation: Beijing BGI-GBI Biotech Co., Ltd., Beijing 101300, China.
authors.forename: Lizhi
authors.initials: L
authors.lastname: Xu
authors.affiliation: Beijing BGI-GBI Biotech Co., Ltd., Beijing 101300, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zheng
authors.affiliation: Beijing BGI-GBI Biotech Co., Ltd., Beijing 101300, China.
authors.forename: Honglei
authors.initials: H
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Dongdajie Road 20, Beijing 100071, China.
authors.forename: Yongqiang
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Center for Disease Control and Prevention of Henan, Zhenzhou, China.
authors.forename: Bianli
authors.initials: B
authors.lastname: Xu
authors.affiliation: Center for Disease Control and Prevention of Henan, Zhenzhou, China. Electronic address: xujinjc@163.com.
authors.forename: Jin
authors.initials: J
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Dongdajie Road 20, Beijing 100071, China. Electronic address: yyh428@sina.com.
authors.forename: Yinhui
authors.initials: Y
authors.lastname: Yang
authors.affiliation: CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, No. 1 Beichen West Road, Beijing, Chaoyang District, 100101, China; Beijing BGI-GBI Biotech Co., Ltd., Beijing 101300, China. Electronic address: chenwj@genomics.org.cn.
authors.forename: Weijun
authors.initials: W
authors.lastname: Chen
mesh_terms: D002681:China; D006801:Humans; D064766:Influenza A Virus, H7N9 Subtype / Q000235:genetics / Q000302:isolation & purification*; D007251:Influenza, Human / Q000175:diagnosis* / Q000821:virology*; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D010614:Pharynx / Q000821:virology; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity
keywords: Avian influenza A/H7N9 virus; Real-time reverse transcription polymerase chain reaction (rRT-PCR)