Epidemiology of 2009 pandemic influenza A (H1N1) deaths in the United States, April-July 2009

Clin Infect Dis. 2011 Jan 1;52 Suppl 1:S60-8. doi: 10.1093/cid/ciq022.


During the spring of 2009, pandemic influenza A (H1N1) virus (pH1N1) was recognized and rapidly spread worldwide. To describe the geographic distribution and patient characteristics of pH1N1-associated deaths in the United States, the Centers for Disease Control and Prevention requested information from health departments on all laboratory-confirmed pH1N1 deaths reported from 17 April through 23 July 2009. Data were collected using medical charts, medical examiner reports, and death certificates. A total of 377 pH1N1-associated deaths were identified, for a mortality rate of .12 deaths per 100,000 population. Activity was geographically localized, with the highest mortality rates in Hawaii, New York, and Utah. Seventy-six percent of deaths occurred in persons aged 18-65 years, and 9% occurred in persons aged ≥ 65 years. Underlying medical conditions were reported for 78% of deaths: chronic lung disease among adults (39%) and neurologic disease among children (54%). Overall mortality associated with pH1N1 was low; however, the majority of deaths occurred in persons aged <65 years with underlying medical conditions.

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
  • Comorbidity
  • Female
  • Geography
  • Humans
  • Infant
  • Influenza A Virus, H1N1 Subtype / isolation & purification*
  • Influenza, Human / epidemiology*
  • Influenza, Human / mortality*
  • Influenza, Human / virology
  • Male
  • Middle Aged
  • Pandemics*
  • Survival Analysis*
  • United States / epidemiology
  • Young Adult