Fig. 4From: Quantitative assessment of the effects of massive nucleic acid testing in controlling a COVID-19 outbreakDaily transmission distance of the outbreak in Yangzhou City, showing the association between daily transmission distance and date (A), daily transmission distance and days after infection (B), and distance needed to control an outbreak and the days after infection (C). The grey dotted lines in A–C are the mean distances (4.12 km in A and B, 2.23 km in C). Assumed simple transmission chain based on analysis of data in Yangzhou, in which circles are sized according to the geographical distance from the index case (1A) (D). The geographical distribution of cases from the assumed simple transmission chain in D, in which the generation of cases is distinguished by color (E). The base layer of maps (E) was based on the China map with review number of GS2016-1595 and unmodified, available open source: https://www.ngcc.cn/ngcc/html/1/391/392/16114.htmlBack to article page