Table 1. Characteristics of the study population and influenza positivity, by age group, Vadu, District Pune, India, May 2009–April 2011.

	Under surveillance		Enrolled		Influenza positive
Age, years	No.	%	No.	%	No.	%
<1r	1,281	1	86	3	5	1
1–4	9,307	8	251	8	39	6
5–14	19,262	16	404	13	143	22
15–29	43,868	38	1426	45	348	52
30–44	24,816	21	554	17	83	12
45–59	10,921	9	279	9	33	5
60+	7,434	6	179	6	14	2
All ages	116,889	100	3179		665