Fig. 3.

Timing and size of SARS-CoV-2 genetic clusters. SARS-CoV-2 was introduced to OUH on at least 607 occasions, with evidence of onward transmission on 43 occasions. Isolates > 1 SNP from any previous sample were defined as distinct introductions and are plotted on separate horizontal lines, according to the date of the first positive sample in OUH for each individual. The size of the red dot indicates number of individuals diagnosed on each day. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)