Estimating the burden of 2009 pandemic influenza A (H1N1) in the United States (April 2009-April 2010)

Clin Infect Dis. 2011 Jan 1;52 Suppl 1:S75-82. doi: 10.1093/cid/ciq012.

Abstract

To calculate the burden of 2009 pandemic influenza A (pH1N1) in the United States, we extrapolated from the Centers for Disease Control and Prevention's Emerging Infections Program laboratory-confirmed hospitalizations across the entire United States, and then corrected for underreporting. From 12 April 2009 to 10 April 2010, we estimate that approximately 60.8 million cases (range: 43.3-89.3 million), 274,304 hospitalizations (195,086-402,719), and 12,469 deaths (8868-18,306) occurred in the United States due to pH1N1. Eighty-seven percent of deaths occurred in those under 65 years of age with children and working adults having risks of hospitalization and death 4 to 7 times and 8 to 12 times greater, respectively, than estimates of impact due to seasonal influenza covering the years 1976-2001. In our study, adults 65 years of age or older were found to have rates of hospitalization and death that were up to 75% and 81%, respectively, lower than seasonal influenza. These results confirm the necessity of a concerted public health response to pH1N1.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Age Distribution
  • Aged
  • Aged, 80 and over
  • Child
  • Child, Preschool
  • Female
  • Hospitalization / statistics & numerical data*
  • Humans
  • Infant
  • Infant, Newborn
  • Influenza A Virus, H1N1 Subtype / isolation & purification*
  • Influenza, Human / epidemiology*
  • Influenza, Human / mortality
  • Influenza, Human / pathology
  • Influenza, Human / virology*
  • Male
  • Middle Aged
  • Pandemics*
  • United States / epidemiology
  • Young Adult