title: Inactivation of the novel avian influenza A (H7N9) virus under physical conditions or chemical agents treatment.
abstract: BACKGROUND
  In the spring of 2013, a novel avian-origin influenza A (H7N9) virus in Eastern China emerged causing human infections. Concerns that a new influenza pandemic could occur were raised. The potential effect of chemical agents and physical conditions on inactivation of the novel avian influenza H7N9 virus had not been assessed.
  
  
  METHODS
  To determine the inactivation effectiveness of the novel avian influenza A (H7N9) virus under various physical conditions and chemical treatments, two H7N9 viruses A/Anhui/1/2013 and A/Shanghai/1/2013 were treated by varied temperatures, ultraviolet light, varied pHs and different disinfectants. The viruses with 107.7 EID50 were exposed to physical conditions (temperature, ultraviolet light and pH) or treated with commercial chemical agents (Sodium Hypochlorite, Virkon®-S, and Ethanol) respectively. After these treatments, the viruses were inoculated in SPF embryonated chicken eggs, the allantoic fluid was collected after 72-96 hours culture at 35°C and tested by haemagglutination assay.
  
  
  RESULTS
  Both of the tested viruses could tolerate conditions under 56°C for 15 minutes or 60°C for 5 minutes, but their infectivity was completely lost under 56°C for 30 minutes, 65°C for 10 minutes, 70°C, 75°C and 100°C for 1 minute. It was also observed that the H7N9 viruses lost their infectivity totally after exposure of ultraviolet light irradiation for 30 minutes or longer time. Additionally, the viruses were completely inactivated at pH less than 2 for 0.5 hour or pH 3 for 24 hours, however, viruses remained infectious under pH treatment of 4-12 for 24 hours. The viruses were totally disinfected when treated with Sodium Hypochlorite, Virkon®-S and Ethanol at recommended concentrations after only 5 minutes.
  
  
  CONCLUSIONS
  The novel avian influenza A (H7N9) virus can be inactivated under some physical conditions or with chemical treatments, but they present high tolerance to moderately acidic or higher alkali conditions. The results provided the essential information for public health intervention of novel H7N9 avian influenza outbreak.
authors.affiliation: Chinese National Influenza Center, National Institute for Viral Disease Control and Prevention, 155 Changbai Road, Beijing 102206, P,R China. yshu@cnic.org.cn.
authors.forename: Shumei
authors.initials: S
authors.lastname: Zou
authors.forename: Junfeng
authors.initials: J
authors.lastname: Guo
authors.forename: Rongbao
authors.initials: R
authors.lastname: Gao
authors.forename: Libo
authors.initials: L
authors.lastname: Dong
authors.forename: Jianfang
authors.initials: J
authors.lastname: Zhou
authors.forename: Ye
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jie
authors.initials: J
authors.lastname: Dong
authors.forename: Hong
authors.initials: H
authors.lastname: Bo
authors.forename: Kun
authors.initials: K
authors.lastname: Qin
authors.forename: Yuelong
authors.initials: Y
authors.lastname: Shu
mesh_terms: D004202:Disinfectants / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D064766:Influenza A Virus, H7N9 Subtype / Q000187:drug effects* / Q000502:physiology / Q000528:radiation effects*; D050296:Microbial Viability / Q000187:drug effects* / Q000528:radiation effects*; D013696:Temperature; D014466:Ultraviolet Rays; D014776:Virus Cultivation; D038301:Virus Inactivation
chemical_list: D004202:Disinfectants
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