[Analysis on the epidemic factors for COVID-19]

As a new infectious disease, the epidemic process of COVID-19 has a series of special influencing factors and conditions. In this paper, some obvious characteristics of this widespread epidemic are discussed, including the new pathogen making people feel confused, the slow onset bringing confusion to the clinic, the miscellaneous source of infection also causing confusion to prevention and control work, the easy route of transmissions leading to a sharp increase of confirmed cases, the high susceptibility of the population leading to a high incidence, and the natural epidemic process coupled with the complexity of natural factors and the superposition of social factors. The positive and effective prevention and control strategies and measures adopted by China have greatly changed the natural epidemic process and trajectory of this epidemic, which has been highly affirmed by the expert group of the World Health Organization and praised by many countries and international organizations. However, to sum up carefully and think deeply, it will be a long-term and arduous work to plan and realize public health security in China and even the world in the future.