title: Influenza-related deaths and hospitalizations in Hong Kong: a subtropical area.
abstract: BACKGROUND
  While influenza vaccination has been widely used in developed countries to reduce mortality and morbidity in high-risk populations, the lack of regional data on the health burden of influenza and the uncertainty of the applicability of data from temperate areas have been major impediments to establishing an evidence-based policy on the wider use of influenza vaccine in tropical and subtropical regions of the world.
  
  
  OBJECTIVE
  The aim of this study was to estimate the annual excess deaths and hospitalizations related to influenza in the Hong Kong Special Administrative Region (HKSAR) for the years 1999 and 2000.
  
  
  METHODS
  Correlation and regression models were used to estimate the excess deaths and hospitalizations related to influenza in the general population of HKSAR for the years 1999 and 2000, using routinely collected mortality and hospitalization data, and virological laboratory data collected by the HKSAR Influenza Surveillance System.
  
  
  RESULTS
  The annual mean excess numbers of deaths related to influenza in Hong Kong were estimated to be 613 for pneumonia and influenza, and 2302 for respiratory and circulatory diseases. The mean excess numbers of hospitalizations attributable to influenza were 4051 for pneumonia and influenza, and 15,873 for respiratory and circulatory diseases. The crude influenza-related mortality and hospitalization rates in Hong Kong, a subtropical area, exceeded those documented in temperate regions.
  
  
  CONCLUSIONS
  The finding of significant mortality and morbidity related to influenza in a subtropical area is in accordance with the results of previous studies in tropical and subtropical regions. This simple methodology can be used for the development of influenza immunization policy in many developing countries in tropical and subtropical regions. The enormous potential of influenza vaccination in saving lives and reducing suffering warrants serious consideration of the expanded use of influenza vaccine in tropical and subtropical regions.
authors.affiliation: Centre for Infectious Disease Prevention and Control, Public Health Agency of Canada, 120 Colonnade Road, Ottawa, Ont., Canada K1A 0K9.
authors.forename: C K
authors.initials: CK
authors.lastname: Li
authors.forename: B C K
authors.initials: BC
authors.lastname: Choi
authors.forename: T W
authors.initials: TW
authors.lastname: Wong
mesh_terms: D002980:Climate; D003906:Developing Countries; D006291:Health Policy; D006723:Hong Kong / Q000453:epidemiology; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007251:Influenza, Human / Q000453:epidemiology / Q000401:mortality*; D011024:Pneumonia, Viral / Q000453:epidemiology / Q000401:mortality; D018570:Risk Assessment; D012307:Risk Factors; D014330:Tropical Medicine