Spatio-temporal propagation of COVID-19 pandemics

Abstract

The new coronavirus known as COVID-19 is spread world-wide since December\n2019. Without any vaccination or medicine, the means of controlling it are\nlimited to quarantine and social distancing. Here we study the spatio-temporal\npropagation of the first wave of the COVID-19 virus in China and compare it to\nother global locations. We provide a comprehensive picture of the spatial\npropagation from Hubei to other provinces in China in terms of distance,\npopulation size, and human mobility and their scaling relations. Since strict\nquarantine has been usually applied between cities, more insight about the\ntemporal evolution of the disease can be obtained by analyzing the epidemic\nwithin cities, especially the time evolution of the infection, death, and\nrecovery rates which affected by policies. We study and compare the infection\nrate in different cities in China and provinces in Italy and find that the\ndisease spread is characterized by a two-stages process. At early times, at\norder of few days, the infection rate is close to a constant probably due to\nthe lack of means to detect infected individuals before infection symptoms are\nobserved. Then at later times it decays approximately exponentially due to\nquarantines. The time evolution of the death and recovery rates also\ndistinguish between these two stages and reflect the health system situation\nwhich could be overloaded.\n