title: The first lack of evidence of H7N9 avian influenza virus infections among pigs in Eastern China.
abstract: In this study, we sought to examine whether evidence existed suggesting that pigs were being infected with the novel H7N9 avian influenza virus. From November 2012 to November 2013, blood was drawn from 1560 pigs from 100 large farms in 4 provinces of eastern China. Many of these pigs were in close proximity to wild birds or poultry. Swine sera were studied using hemagglutinin inhibition (HI) assays and enzyme-linked immunosorbent assays (ELISAs) against the H7 antigen derived from the emergent H7N9 avian influenza virus (AIV). Only 29 of the 1560 samples had HI titers of 1:20 when using the H7N9 AIV antigens, and none of the 29 (H7N9 AIV) HI-positive samples were positive when using ELISA, indicating that no samples were positive for H7N9. The negative results were also verified using a novel competitive HA-ELISA. As pigs have been shown to be infected with other avian influenza viruses and as the prevalence of novel influenza A viruses (e.g., H7N9 AIV) may be increasing among poultry in China, similar seroepidemiological studies of pigs should be periodically conducted in the future.
authors: State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, People's Republic of China.
authors: Fu-Rong
authors: FR
authors: Zhao
authors: State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, People's Republic of China.
authors: Dong-Hui
authors: DH
authors: Zhou
authors: State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, People's Republic of China.
authors: Tong
authors: T
authors: Lin
authors: State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, People's Republic of China.
authors: Jun-Jun
authors: JJ
authors: Shao
authors: State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, People's Republic of China; Northeast Agricultural University, College of Veterinary Medicine, Haerbin, Heilongjiang Province 150030, People's Republic of China.
authors: Ping
authors: P
authors: Wei
authors: State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, People's Republic of China. Electronic address: zhangyongguang@caas.cn.
authors: Yong-Guang
authors: YG
authors: Zhang
authors: State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, People's Republic of China. Electronic address: changhuiyun@caas.cn.
authors: Hui-Yun
authors: HY
authors: Chang
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D001717:Birds; D002681:China / Q000453:epidemiology; D004797:Enzyme-Linked Immunosorbent Assay; D006385:Hemagglutination Inhibition Tests; D064766:Influenza A Virus, H7N9 Subtype / Q000276:immunology*; D005585:Influenza in Birds / Q000635:transmission; D009976:Orthomyxoviridae Infections / Q000175:diagnosis / Q000453:epidemiology / Q000662:veterinary* / Q000821:virology; D016036:Seroepidemiologic Studies; D013552:Swine; D013553:Swine Diseases / Q000175:diagnosis* / Q000453:epidemiology / Q000821:virology*
chemical_list: D000914:Antibodies, Viral
keywords: Avian influenza virus; HA-ELISA; Seroprevalence; Swine serum