The second thing is to trace contacts of this individual. That is, a detailed account from that individual of where they have been, what they did, who did they meet with, how long did they spend is required. Using this comprehensive list of individuals enables the health authorities to assess risk and follow them up through the stringent protocols.
More people are mobilized to undertake contact tracing and the authorities have to make sure the hospitals are having enough trained staff and that healthcare staff are well protected. For now, the best advice for people is to make sensible travel plans and ensure good hygiene wherever they go. It’s OK to be a bit obsessive about hygiene, frequently washing hands with soap and water for the time being.