evidence: The outbreak, which started in Wuhan in Hubei province, China, in early December, has now spread to 181 countries and regions. China was relatively successful in containing its outbreak to Hubei. But the virus has spread rapidly between and within other countries. China accounted for almost 80% of the first 100,000 patients identified, but the United States now contains more cases than any other country, with more than 20% of the world’s total. [...] The coronavirus outbreak has spread to 46 countries other than China — and now seems to be spreading faster outside China than inside. [...] Researchers are using flight data to create models of the virus’s possible spread around the world. One model identified 30 countries at risk of importing SARS-CoV-2, on the basis of the large number of flights from Wuhan, the outbreak’s epicentre, and from other cities in China with lots of travellers from Wuhan. But several of those countries, including Thailand, Vietnam, Cambodia and Malaysia, have reported fewer cases than the model predicts. Indonesia, another country at risk, has yet to report a single case.