Table 2.

Incidence of pandemic and seasonal influenza A viruses among hospitalized pediatric ARI in different age groups during pandemic and post-pandemic periods

Age group	Population*	Incidence per 100 000 population (95% CI)
		Overall				First year of outbreak				Second year of outbreak
		April 2009 to March 2011				April 2009 to March 2010				April 2010 to March 2011
		Seasonal		Pandemic		Seasonal		Pandemic		Seasonal		Pandemic
Months	n	Cases	Incidence	Cases	Incidence	Cases	Incidence	Cases	Incidence	Cases	Incidence	Cases	Incidence
≤11	2250	9	200 (105–379)	9	200 (105–379)	5	222 (94–519)	2	89 (24–323)	4	118 (96–456)	7	311 (151–641)
12–23	2431	19	390 (250–609)	14	288 (172–682)	8	329 (167–648)	6	247 (113–537)	11	452 (253–808)	8	329 (167–648)
24–59	9254	17	92 (57–147)	23	124 (83–186)	11	119 (66–213)	11	119 (66–213)	6	56 (30–141)	12	130 (74–227)
<60	13 935	45	161 (120–216)	46	165 (124–220)	24	172 (116–256)	19	136 (87–213)	21	150 (99–230)	27	194 (133–282)
≥60	34 325	5	7 (3–17)	11	16 (9–28)	4	11 (5–30)	6	17 (8–38)	1	3 (0–15)	5	15 (6–34)
Total	48 260	50	52 (39–68)	57	59 (46–76)	28	58 (40–84)	25	52 (35–76)	22	46 (30–69)	32	66 (47–94)

ARI, acute respiratory infection.

^*Data from population census survey in 2006.