Comparative Analysis of COVID-19 Transmission Patterns in Three Chinese Regions vs. South Korea,Italy and Iran

Junyu He; Guangwei Chen; Yutong Jiang; Runjie Jin; Mingjun He; Ashton Shortridge; Jiaping Wu; George Christakos

Health-codes  A 3-color health code was used to manage the local flow of people by identifying the condition of people entering a local county or city (Zhejiang was the first province to use this code).  People applied for health code in specific cities based on their location, current health condition and the places they had been during the past two weeks.  A red health code meant that an individual was infected, or suspected, or had closely contacted an infected (or suspected) individual, or had possibly contacted an infected (or suspected) individual, or came from a severely epidemic-affected region. In all cases, people were quarantined for 14 days, reporting their health condition every day. After that, an individual's code would turn into green.  A yellow health code meant that one came from a severe disease region or had potentially contacted someone from that region. In this case, one needed to be quarantined for 7 days, having to report one's health condition during each day. After that, an individual's code would turn to green.  A green health code meant that the individual had very low risk of getting the disease and was free to travel.  Schools and companies also used this code to monitoring the health condition of students, teachers and staff.  Local governments, schools and companies may have more restricted codes for allowing their staff to return to these places and maintain their basic functions.