First, these data are collected after the outbreak in China. At that time, the Chinese government implemented strict lock-down. Thus the data may not be used for reference. Also, they're much fewer cases reported in the tropical area. But that's not because there are truly fewer cases. Instead, maybe those underdeveloped countries in the tropical area don't have enough methods to diagnose and report it. All these variables may affect those existing models untenable (Mecenas et al., 2020).