The intensity of COVID-19 outbreaks is modulated by variation in SARS-CoV-2 free-living survival and environmental transmission

Ogbunugafor, C. Brandon; Miller-Dickson, Miles; Meszaros, Victor A.; Gomez, Lourdes M.; Murillo, Anarina L.; Scarpino, Samuel V.

COVID-19 has circled the globe, rapidly expanding into a pandemic within a matter of weeks. While early studies revealed important features of SARS-CoV-2 transmission, the role of variation in free-living virus survival in modulating the dynamics of outbreaks remains unclear. Using an empirically determined understanding of SARS-CoV-2 natural history and detailed, country-level case data, we elucidate how variation in free-living virus survival influences key features of COVID-19 epidemics. Our findings suggest that COVID-19’s basic reproductive number ([Formula: see text]) and other key signatures of outbreak intensity are defined by transmission between infected individuals and the environment. Summarizing, we propose that variation in environmental transmission may explain observed differences in disease dynamics from setting to setting, and can inform public health interventions.