TABLE 2

Rates of Laboratory-Confirmed Influenza Hospitalization per 1000 Children and 95% Confidence Intervals by Age Group, Influenza Season (November–April), and Influenza Virus Type

SeasonRate per 1000 Children (95% Confidence Interval)
<6 mo6 mo–<2 y2 y–<5 y<5 y
All influenza
 2004–53.4 (2.5–4.5)0.7 (0.4–1.0)0.19 (0.09–0.30)0.67 (0.53–0.83)
 2005–62.4 (1.0–4.0)0.6 (0.3–1.0)0.15 (0.03–0.29)0.50 (0.31–0.71)
 2006–72.0 (0.9–3.3)0.4 (0.1–0.7)0.07 (0.00–0.18)0.36 (0.20–0.55)
 2007–84.3 (2.5–6.3)1.3 (0.7–1.8)0.22 (0.07–0.40)0.97 (0.71–1.25)
 2008–91.6 (0.7–2.6)0.4 (0.1–0.7)0.27 (0.11–0.46)0.44 (0.28–0.61)
 2004–92.7 (2.1–3.3)0.6 (0.5–0.8)0.19 (0.13–0.25)0.58 (0.50–0.67)
Influenza A
 2004–52.8 (2.0–3.8)0.6 (0.4–0.9)0.10 (0.03–0.17)0.53 (0.40–0.66)
 2005–61.8 (0.7–3.1)0.6 (0.3–1.0)0.15 (0.03–0.29)0.44 (0.28–0.63)
 2006–71.3 (0.4–2.5)0.4 (0.1–0.7)0.04 (0.00–0.11)0.27 (0.14–0.43)
 2007–84.2 (2.5–6.3)1.0 (0.6–1.6)0.11 (0.00–0.25)0.84 (0.59–1.11)
 2008–91.3 (0.5–2.2)0.3 (0.1–0.5)0.08 (0.00–0.19)0.27 (0.15–0.41)
 2004–92.3 (1.7–2.8)0.5 (0.4–0.7)0.09 (0.05–0.14)0.46 (0.38–0.53)
Influenza Ba
 2004–90.4 (0.2–0.7)0.08 (0.03–0.15)0.10 (0.05–0.15)0.13 (0.09–0.17)
  • a Overall rates of influenza B are shown because the number of influenza B cases identified in each age group by individual year was much smaller than the number of influenza A cases.