Identify
The first step in the “3I system” is identification, i.e. identification of possibly infected persons (based on possible exposure or exposure history) and infected persons with any epidemiological risk factor. These individuals can be identified by on-site inquiry and examination. Medical personnel must record information on exposure history and contact history for the early detection of infected patients and possibly infected patients, and must be aware of this information to prevent missed or incorrect diagnoses.
One of the characteristics of the “3I system” is to display posters or even small cards that all medical staff can quickly read and understand. These displays provide basic information on the diagnosis and differential diagnosis of new infectious diseases. In this specific case, these displays can describe the methods used for detection and diagnosis of COVID-19, and make it easier for medical staff to identify potential patients. Early identification is the key to reduce the spread of COVID-19, so it is particularly important to apply these methods to prevent and control COVID-19 (Lai et al., 2020).