title: Significantly elevated number of human infections with H7N9 virus in Jiangsu in eastern China, October 2016 to January 2017.
abstract: Since first identified in 2013, the H7N9 virus has caused several waves of human infections in China, with a current wave including a number of patients with very severe disease. Jiangsu is one of the most impacted provinces, whereby as of 31 January 2017, the number of human infections (n = 109) in the ongoing fifth H7N9 wave has exceeded the sum of those in the four preceding ones. Ten of 13 cities in Jiangsu have been affected, and clustered infections as well as one co-infection with seasonal influenza have been observed. With a median age of 58 years and 74.3% (81/109) of patients being male, the characteristics of cases are similar to those in previous waves, however patients with H7N9 seem to have an accelerated disease progression. Preliminary case fatality remains above 30%. No significant viral mutations have been found in key functional loci. Environmental H7N9 detection rate and number of days with high risk ambient temperatures were both significantly elevated during the month of December 2016 when most human infections were reported. A number of municipal governments in Jiangsu have implemented live poultry market closures to impede viral transmission to humans. A detectable decline in human infections has been observed in these municipalities and the entire province since January 2017.
authors.affiliation: Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China.|These authors contributed equally to this work.
authors.forename: Xiang
authors.initials: X
authors.lastname: Huo
authors.affiliation: These authors contributed equally to this work.|Suzhou Center for Disease Control and Prevention, Suzhou, China.
authors.forename: Liling
authors.initials: L
authors.lastname: Chen
authors.affiliation: Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China.|These authors contributed equally to this work.
authors.forename: Xian
authors.initials: X
authors.lastname: Qi
authors.affiliation: Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China.
authors.forename: Haodi
authors.initials: H
authors.lastname: Huang
authors.affiliation: Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China.
authors.forename: Qigang
authors.initials: Q
authors.lastname: Dai
authors.affiliation: Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China.
authors.forename: Huiyan
authors.initials: H
authors.lastname: Yu
authors.affiliation: Suzhou Center for Disease Control and Prevention, Suzhou, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Xia
authors.affiliation: Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China.
authors.forename: Wendong
authors.initials: W
authors.lastname: Liu
authors.affiliation: Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Xu
authors.affiliation: Nanjing Medical University, Nanjing, China.
authors.forename: Wang
authors.initials: W
authors.lastname: Ma
authors.affiliation: Suzhou Center for Disease Control and Prevention, Suzhou, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China.
authors.forename: Changjun
authors.initials: C
authors.lastname: Bao
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D002681:China / Q000453:epidemiology; D004196:Disease Outbreaks; D004784:Environmental Monitoring; D004787:Environmental Pollution / Q000009:adverse effects* / Q000517:prevention & control; D005260:Female; D006801:Humans; D064766:Influenza A Virus, H7N9 Subtype / Q000302:isolation & purification*; D005585:Influenza in Birds / Q000453:epidemiology / Q000635:transmission*; D007251:Influenza, Human / Q000188:drug therapy / Q000453:epidemiology / Q000517:prevention & control / Q000635:transmission / Q000821:virology*; D008297:Male; D008875:Middle Aged; D011200:Poultry; D012306:Risk; D012720:Severity of Illness Index
keywords: H7N9; Human; influenza; meteorology; mutation; pandemic