Table 2. Influenza positivity among Urban and peri-urban Population in and around Delhi, North India, 2007–2010.

Year		# tested	# Influenza +ve		Influenza B		SeasonalInfluenza A				InfluenzaA(H1N1)pdm09
							H3N2		H1N1
			n	%	n	%*	n	%*	n	%*	n	%*
2007	Urban	417	28	7	11	39	1	4	16	57	NA	NA
	Peri-urban	293	27	9	16	59	0	0	11	41	NA	NA
2008	Urban	410	26	6	22	85	3	11	1	4	NA	NA
	Peri-urban	412	29	7	24	83	3	10	2	7	NA	NA
2009	Urban	675	238	35	26	11	55	23	9	4	148 Ψ	62
	Peri-urban	396	77	21	2	3	55 €	71	6	8	14	18
2010	Urban	314	72	23	24	33	6	8	0	0	42 Ψ	58
	Peri-urban	347	44	13	27	61	0	0	0	0	17	39
Total	Urban	1816	364	20	83	23	65	18	26	7	190	52
	Peri-urban	1448	177	12	69	39	58	33	19	11	31	17

*Denominator for the percentage is # influenza positive for that year.

^€ p<0.01 (highly significant for Influenza A (H3N2) in 2009, OR = 1.8, CI – 1.2–2.7)for peri-urban area.

^Ψ p<0.001 (highly significant for pandemic Influenza A(H1N1)pdm09 in 2009, OR = 7.7, CI – 4.2–14) and 2010 (OR = 3.0, CI – 1.6–5.6) for urban areas.