TABLE 2

Age, Influenza Virus Type and Subtype, and Presence of High-Risk Medical Conditions Among Children Who Died of Influenza-Associated Illness by Influenza Season: United States, October 2004 Through September 2012

2004–2005 (n = 47)2005–2006 (n = 46)2006–2007 (n = 77)2007–2008 (n = 88)2008–2009a (n = 133)2009–2010a (n = 282)2010–2011 (n = 122)2011–2012 (n = 35)
Age, median (IQR), y5 (1–11)3 (0–8)7 (1–11)5 (1–10)8 (2–13)8.5 (3–13)5 (1–11)5 (2–10)
Influenza viruses, %
 Influenza A6063716377996271
  pH1N1NANANANA45802529
  A, subtype not distinguished5350424422191623
  Seasonal A (H1N1)002638000
  A (H3N2)613415202020
 Influenza B362623342313826
 A (H3N2)/B coinfection00010000
 Influenza, type not distinguished411520003
No high-risk medical conditionsb, %3347624948324947
One or more high-risk medical conditionb, %6753385152685153
  • N = 830. IQR, interquartile range; NA, not applicable.

  • a Influenza seasons defined as October 1 through September 30 of the following year with the exception of the pandemic pH1N1 period, during which influenza seasons were defined as October 1, 2008, through August 29, 2009, and August 30, 2009, through September 30, 2010.

  • b n = 45, 38, 71, 82, 127, 277, 120, and 34 for years 2004–2005, 2005–2006, 2006–2007, 2007–2008, 2008–2009, 2009–2010, 2010–2011, 2011–2012, respectively.