Estimating number of global importations of COVID-19 from Wuhan, risk of transmission outside mainland China and COVID-19 introduction index between countries outside mainland China

Haoyang Sun; Borame Lee Dickens; Mark Chen; Alex Richard Cook; Hannah Eleanor Clapham

We used the information on the date, location, and travel history of each reported COVID-19 case, which was synthesized and made publicly available by the nCoV-2019 Data Working Group. 13 For each country or territory outside of mainland China, we collated data on the total number of reported COVID-19 cases imported from Wuhan only (not from other places in China), based on the epidemiological data updated as of 7 th February-15 days since the Wuhan shutdown (Table S1) . For a small number of cases, we were unable to identify the cities from which they were imported. We included these into our data as having originated from Wuhan to avoid producing false positive results when we later on identified countries that may have under-detected SARS-CoV-2 importation from Wuhan.