title: Burden of influenza-associated deaths in the Americas, 2002-2008.
abstract: BACKGROUND
  Influenza disease is a vaccine-preventable cause of morbidity and mortality. The Pan American Health Organization (PAHO) region has invested in influenza vaccines, but few estimates of influenza burden exist to justify these investments. We estimated influenza-associated deaths for 35 PAHO countries during 2002-2008.
  
  
  METHODS
  Annually, PAHO countries report registered deaths. We used respiratory and circulatory (R&C) codes from seven countries with distinct influenza seasonality and high-quality mortality data to estimate influenza-associated mortality rates by age group (0-64, 65-74, and ≥ 75 years) with a Serfling regression model or a negative binomial model. We calculated the percent of all R&C deaths attributable to influenza by age group in these countries (etiologic fraction) and applied it to the age-specific mortality in 13 countries with good mortality data but poorly defined seasonality. Lastly, we grouped the remaining 15 countries into WHO mortality strata and applied the age and mortality stratum-specific rate of influenza mortality calculated from the 20 countries. We summed each country's estimate to arrive at an average total annual number and rate of influenza deaths in the Americas.
  
  
  RESULTS
  For the 35 PAHO countries, we estimated an annual mean influenza-associated mortality rate of 2·1/100,000 among <65-year olds, 31·9/100 000 among those 65-74 years, and 161·8/100,000 among those ≥ 75 years. We estimated that annually between 40,880 and 160,270 persons (mean, 85,100) die of influenza illness in the PAHO region.
  
  
  CONCLUSIONS
  Influenza remains an important cause of mortality in the Americas.
authors.affiliation: Influenza Division, US Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors.forename: Po-Yung
authors.initials: PY
authors.lastname: Cheng
authors.affiliation: Influenza Division, US Centers for Disease Control and Prevention, Atlanta, GA, USA.|Pan American Health Organization, Washington, DC, USA.
authors.forename: Rakhee
authors.initials: R
authors.lastname: Palekar
authors.affiliation: Influenza Division, US Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Azziz-Baumgartner
authors.affiliation: Influenza Division, US Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors.forename: Danielle
authors.initials: D
authors.lastname: Iuliano
authors.affiliation: Institute of Mathematics and Statistics, University of São Paulo, São Paulo, Brazil.
authors.forename: Airlane P
authors.initials: AP
authors.lastname: Alencar
authors.affiliation: Influenza Division, US Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Bresee
authors.affiliation: Pan American Health Organization, Washington, DC, USA.
authors.forename: Otavio
authors.initials: O
authors.lastname: Oliva
authors.affiliation: Pan American Health Organization, Washington, DC, USA.
authors.forename: Maria de Fatima Marinho
authors.initials: Mde F
authors.lastname: de Souza
authors.affiliation: Influenza Division, US Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors.forename: Marc-Alain
authors.initials: MA
authors.lastname: Widdowson
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000569:Americas; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D053118:Influenza A Virus, H1N1 Subtype; D007252:Influenza Vaccines; D007251:Influenza, Human / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D013997:Time Factors; D055815:Young Adult
chemical_list: D007252:Influenza Vaccines
keywords: Americas; influenza; model; mortality