Table 1. Prevalence of H7N9 virus among samples from different sampling sites between January 2013 and March 2014.

Period	Poultry markets	Poultry farms	Backyard poultry pens	Poultry processing factories	Wild bird habitats
January-December 2013	3.76%(48/1277)	0.55%(4/733)	0%(0/335)	0%(0/25)	0%(0/98)
January 2014	20.81%(482/2316)	4.76%(5/105)	0%(0/103)	0%(0/6)	0%(0/9)
February 2014	8.47%(78/921)	0%(0/117)	0%(0/97)	16.67%(1/6)	0%(0/0)
March 2014	21.07%(59/280)	0%(0/156)	0%(0/114)	16.67%(3/18)	0%(0/5)
Total	13.94%(667/4784)	0.81%(9/1111)	0%(0/649)	7.27%(4/55)	0%(0/112)