In determining close contacts and analyzing their risk of infection, a comprehensive judgment should be made by taking into account the clinical manifestations of the patient contacted, the mode of contact with the patient, the protective measures taken at the time of contact, and the degree of exposure to the environment and objects contaminated by the patient. Therefore, the determination of close contacts should be left to professionals, and for the general public, it is sufficient to report and provide relevant information truthfully. In addition to friends, relatives, and colleagues of the patient, the most common close contacts are people who travel on the same transportation. Therefore, you should pay attention to your flight number and high speed train information, and pay attention to the information of the patient’s transportation with the public, and if you are a passenger, you need to report and isolate at home. Content source: Dr. You Lai