Identification of thresholds on population density for understanding transmission of COVID-19

Pathways of transmission of coronavirus (COVID-19) disease in the human population are still emerging. However, empirical observations suggest that dense human settlements are the most adversely impacted, corroborating a broad consensus that human-to-human transmission is a key mechanism for the rapid spread of this disease. Here, using logistic regression techniques, estimates of threshold levels of population density were computed corresponding to the incidence in the human population. Regions with population densities greater than 3000 person per square mile in the United States have about 95% likelihood to get infected with COVID-19. Since case numbers of COVID-19 dynamically changed each day until November 30, 2020, ca. 4% of US counties were at 50% or higher risk of COVID-19 transmission. While threshold on population density is not the sole indicator for predictability of coronavirus in human population, yet it is one of the key variables on understanding and rethinking human settlement in urban landscapes.