Lesson Learned from the Emergence of Influenza Pandemic H1N1 in 2009 in Indonesia: The Importance of Influenza-Like Illness (ILI) Surveillance

Table 2

Case proportion, type, and subtype of seasonal influenza monthly.

Month	No. of ILI cases	Flu B	H1N1	H3N2	H5N1	H1pdm09	Flu A not type
January	87	10	3	5	0	0	8
February	81	14	4	1	0	0	2
March	103	18	6	0	0	0	2
April	277	9	4	2	0	1	2
May	345	8	4	2	0	0	0
June	366	1	9	10	0	8	2
July	474	0	10	9	0	83	16
August	475	0	1	6	0	93	28
September	212	0	0	3	0	1	12
October	279	9	0	1	0	0	11
November	277	4	0	1	0	1	3
December	278	7	1	1	0	0	4
Total	3254	80	42	41	0	187	89