Abstract
Early forecasting is important for health officials and decision-makers to respond to public health emergencies such as the 2019 novel coronavirus (COVID-19) outbreak. The spread of epidemic is mainly impacted by the interaction among agents, i.e., individual, hospital and government. In an effort to efficiently mitigate the impact of the virus, this original study designed a multi-agents complex adaptive system model of COVID-19 to detect the trend of the spread in 8 countries by simulating the adaptation and interaction among the agents. The results show that there should be 127,726 infections in China, 12,000 in South Korea, 729,377 in the USA, 176,623 in Italy, 194,359 in Spain, 165,122 in Germany, 177,462 in France and 149,540 in UK. It is impossible to screen and report all the cases, and the detection rate may be 82% in Italy, 65% in China, 55% in the USA, and 41% in UK on April 8, 2020. Scenario simulation results imply that action time is the most important factor in containing the spread of epidemic. If China had locked down Wuhan city five days later, the total infection would be tripled. The forces of individual, hospital and government should be united in fighting the virus.