Arrival place 14 days, received SMS.

Only people suspected of being infected with COVID-19 virus will receive streaming messages. Br Epidemiological investigation is the key to epidemic control, and the information collected by epidemiological investigation can play a key role in effectively curbing the epidemic. The necessity and importance of epidemiological investigation: tracing the source of infection and looking for potential close contacts of cases; Mobile information is the basis of medical isolation observation; Describe/analyze the important basic data sources of epidemiology; Mining information, discovering the law of disease transmission and controlling the spread of the epidemic; An important information source for scientific decision-making in health sector. To put it more bluntly, the current model is to understand: the road you have traveled, the people you met, and what happened at every important time in the past.