Ecological Study on COVID-19 on the early growth rate and historical environmental (temperature, precipitation, air pollution) and socio-economic factors in 96 countries using GAM (Generalized Additive models)

Few studies looked at the determinants of the COVID-19 spread. This study investigates the link between historical socio-economic, environmental and health indicators and the transmission of COVID-19 in 96 countries using Generalized Additive Models. Our results indicated that the exponential early growth rate calculated on a period of seven days since the 100th case in each country is significantly and positively associated with the number of air passengers carried (p<0.0001). This spread was also associated with historical winter temperatures (p=0.02), the Universal Health Coverage Index (p=0.006) from World health Organization, GDP per capita (p=0.03) and the prevalence of overweight (=0.004) and undernourishment (p=0.09). In the sensitivity analysis, these results remained similar for a period of 14 days and with a growth rate since the 50th case. In conclusion, environmental effects on COVID-19 early transmission in this ecological study seem to be small.