title: Influenza-associated mortality in temperate and subtropical Chinese cities, 2003-2008.
abstract: OBJECTIVE
  To estimate influenza-associated mortality in urban China.
  
  
  METHODS
  Influenza-associated excess mortality for the period 2003-2008 was estimated in three cities in temperate northern China and five cities in the subtropical south of the country. The estimates were derived from models based on negative binomial regressions, vital statistics and the results of weekly influenza virus surveillance.
  
  
  RESULTS
  Annual influenza-associated excess mortality, for all causes, was 18.0 (range: 10.9-32.7) deaths per 100,000 population in the northern cities and 11.3 (range: 7.3-17.8) deaths per 100,000 in the southern cities. Excess mortality for respiratory and circulatory disease was 12.4 (range: 7.4-22.2) and 8.8 (range: 5.5-13.6) deaths per 100,000 people in the northern and southern cities, respectively. Most (86%) deaths occurred among people aged ≥ 65 years. Influenza-associated excess mortality was higher in B-virus-dominant seasons than in seasons when A(H3N2) or A(H1N1) predominated, and more than half of all influenza-associated mortality was associated with influenza B virus.
  
  
  CONCLUSIONS
  Between 2003 and 2008, seasonal influenza, particularly that caused by the influenza B virus, was associated with substantial mortality in three cities in the temperate north of China and five cities in the subtropical south of the country.
authors.affiliation: Chinese Centre for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing, 102206, China.
authors.forename: Luzhao
authors.initials: L
authors.lastname: Feng
authors.forename: David K
authors.initials: DK
authors.lastname: Shay
authors.forename: Yong
authors.initials: Y
authors.lastname: Jiang
authors.forename: Hong
authors.initials: H
authors.lastname: Zhou
authors.forename: Xin
authors.initials: X
authors.lastname: Chen
authors.forename: Yingdong
authors.initials: Y
authors.lastname: Zheng
authors.forename: Lili
authors.initials: L
authors.lastname: Jiang
authors.forename: Qingjun
authors.initials: Q
authors.lastname: Zhang
authors.forename: Hong
authors.initials: H
authors.lastname: Lin
authors.forename: Shaojie
authors.initials: S
authors.lastname: Wang
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Ying
authors.forename: Yanjun
authors.initials: Y
authors.lastname: Xu
authors.forename: Nanda
authors.initials: N
authors.lastname: Wang
authors.forename: Zijian
authors.initials: Z
authors.lastname: Feng
authors.forename: Cecile
authors.initials: C
authors.lastname: Viboud
authors.forename: Weizhong
authors.initials: W
authors.lastname: Yang
authors.forename: Hongjie
authors.initials: H
authors.lastname: Yu
mesh_terms: D017677:Age Distribution; D000368:Aged; D002423:Cause of Death; D002681:China / Q000453:epidemiology; D002980:Climate; D006801:Humans; D009980:Influenza A virus / Q000302:isolation & purification*; D009981:Influenza B virus / Q000302:isolation & purification*; D007251:Influenza, Human / Q000401:mortality* / Q000821:virology; D012044:Regression Analysis; D018571:Sentinel Surveillance