title: A combination of serological assays to detect human antibodies to the avian influenza A H7N9 virus.
abstract: Human infection with avian influenza A H7N9 virus was first identified in March 2013 and represents an ongoing threat to public health. There is a need to optimize serological methods for this new influenza virus. Here, we compared the sensitivity and specificity of the hemagglutinin inhibition (HI), microneutralization (MN), and Western blot (WB) assays for the detection of human antibodies against avian influenza A (H7N9) virus. HI with horse erythrocytes (hRBCs) and a modified MN assay possessed greater sensitivity than turkey erythrocytes and the standard MN assay, respectively. Using these assays, 80% of tested sera from confirmed H7N9 cases developed detectable antibody to H7N9 after 21 days. To balance sensitivity and specificity, we found serum titers of ≥20 (MN) or 160 (HI) samples were most effective in determining seropositive to H7N9 virus. Single serum with HI titers of 20-80 or MN titer of 10 could be validated by each other or WB assay. Unlike serum collected from adult or elderly populations, the antibody response in children with mild disease was low or undetectable. These combinations of assays will be useful in case diagnosis and serologic investigation of human cases.
authors.affiliation: National Institute for Viral Disease Control and Prevention, China CDC, Key Laboratory for Medical Virology, National Health and Family Planning Commission, Beijing, China.
authors.forename: Libo
authors.initials: L
authors.lastname: Dong
authors.affiliation: National Institute for Viral Disease Control and Prevention, China CDC, Key Laboratory for Medical Virology, National Health and Family Planning Commission, Beijing, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Bo
authors.affiliation: National Institute for Viral Disease Control and Prevention, China CDC, Key Laboratory for Medical Virology, National Health and Family Planning Commission, Beijing, China.
authors.forename: Tian
authors.initials: T
authors.lastname: Bai
authors.affiliation: National Institute for Viral Disease Control and Prevention, China CDC, Key Laboratory for Medical Virology, National Health and Family Planning Commission, Beijing, China.
authors.forename: Rongbao
authors.initials: R
authors.lastname: Gao
authors.affiliation: National Institute for Viral Disease Control and Prevention, China CDC, Key Laboratory for Medical Virology, National Health and Family Planning Commission, Beijing, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Dong
authors.affiliation: National Institute for Viral Disease Control and Prevention, China CDC, Key Laboratory for Medical Virology, National Health and Family Planning Commission, Beijing, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: National Institute for Viral Disease Control and Prevention, China CDC, Key Laboratory for Medical Virology, National Health and Family Planning Commission, Beijing, China.
authors.forename: Junfeng
authors.initials: J
authors.lastname: Guo
authors.affiliation: National Institute for Viral Disease Control and Prevention, China CDC, Key Laboratory for Medical Virology, National Health and Family Planning Commission, Beijing, China.
authors.forename: Shumei
authors.initials: S
authors.lastname: Zou
authors.affiliation: National Institute for Viral Disease Control and Prevention, China CDC, Key Laboratory for Medical Virology, National Health and Family Planning Commission, Beijing, China.
authors.forename: Jianfang
authors.initials: J
authors.lastname: Zhou
authors.affiliation: National Institute for Viral Disease Control and Prevention, China CDC, Key Laboratory for Medical Virology, National Health and Family Planning Commission, Beijing, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: National Institute for Viral Disease Control and Prevention, China CDC, Key Laboratory for Medical Virology, National Health and Family Planning Commission, Beijing, China.
authors.forename: Li
authors.initials: L
authors.lastname: Xin
authors.affiliation: National Institute for Viral Disease Control and Prevention, China CDC, Key Laboratory for Medical Virology, National Health and Family Planning Commission, Beijing, China.
authors.forename: Xiaodan
authors.initials: X
authors.lastname: Li
authors.affiliation: National Institute for Viral Disease Control and Prevention, China CDC, Key Laboratory for Medical Virology, National Health and Family Planning Commission, Beijing, China.
authors.forename: Cuiling
authors.initials: C
authors.lastname: Xu
authors.affiliation: National Institute for Viral Disease Control and Prevention, China CDC, Key Laboratory for Medical Virology, National Health and Family Planning Commission, Beijing, China.
authors.forename: Dayan
authors.initials: D
authors.lastname: Wang
authors.affiliation: National Institute for Viral Disease Control and Prevention, China CDC, Key Laboratory for Medical Virology, National Health and Family Planning Commission, Beijing, China.
authors.forename: Yuelong
authors.initials: Y
authors.lastname: Shu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood / Q000276:immunology*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D064766:Influenza A Virus, H7N9 Subtype / Q000276:immunology*; D009980:Influenza A virus / Q000276:immunology; D007251:Influenza, Human / Q000175:diagnosis / Q000276:immunology*; D008875:Middle Aged; D009500:Neutralization Tests; D009976:Orthomyxoviridae Infections / Q000276:immunology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D000914:Antibodies, Viral
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