Figure 1From: How to interpret the transmissibility of novel influenza A(H7N9): an analysis of initial epidemiological data of human cases from ChinaTemporal distribution and transmission tree of the novel influenza A(H7N9).A. Temporal distribution of confirmed cases according to the date of illness onset by history of contact with birds (nā=ā109 with known date of illness onset as of 1 May 2013; the dates of illness onset for other 20confirmed cases have not been known including 1 asymptomatic infected with a history of contact with bird). Cases with a known history of contact with bird are highlighted in dark grey, while cases without contact are in white.B. The transmission tree that classifies cases into those caused by bird-to-human transmission (grey) and human-to-human transmission (white). A virus with substantial human-to-human transmission potential could yield many subsequent generations of cases caused by human-to-human transmission.Back to article page