Spatiobehavioral characteristics are stable for, and hence predictive of, most cases of contagious diseases. They should be acknowledged as a formal way of defining the epidemiology of new contagious diseases at the early stage, enabling health authorities to implement precision control and prevention of the disease at the first moment possible. Behind the slow or lack of response to the COVID-19 epidemic in most countries is the chicken-and-egg situation that, in traditional epidemiological study designs, the epidemiology of a new disease or epidemic cannot be well known until a large enough number of infected cases appear . Also, traditional ways of defining the epidemiology of new diseases focus on the clinical and individual characteristics of infected cases, which are inherently retrospective and can only be summarized as afterthoughts. In addition, most, if not all, clinical and individual characteristics have varied among infected cases, which gives us uncertainties in prospectively identifying populations at (high) risk for early warning and timely control. If we could start over again, facing a forthcoming epidemic with high contagiousness and all these complexities, how could we be better prepared? Does defining its epidemiology have to occur prior to deciding to take statutory measures for preventing its spread? Can any aspect of the epidemiology of a new contagious disease be defined at its early stage and for all places once it has occurred in one place? Defining one aspect of the epidemiology of COVID-19 - spatiobehavioral characteristics - has actually been practiced unconsciously or subconsciously during the COVID-19 epidemic. Facing new contagious diseases, spatiobehavioral characteristics may work better than other epidemiological characteristics in defining the epidemiology because they are stable for, and hence predictive of, most (if not all) infected cases; that is to say, most if not all infected cases have had close spatial contact with infectors for a certain amount of time. The spatial contact among human populations at a given moment is driven by human behaviors and can be monitored; hence, the contact at the next moment could be predicted. Thus, the spatiobehavioral characteristics of infected cases could be defined, or even precisely quantified, at the first moment possible on the basis of a small number of cases, and this would hold great potential for prospectively predicting populations at risk at a high spatial resolution. Submit manuscript via https://www.scholarscentral.org/submissions/epidemiology-open-access.html or email us at submissions@omicsonline.com Regards Alex John Managing Editor Epidemiology: Open Access