Monitoring transmissibility and mortality of COVID-19 in Europe

OBJECTIVES: As a global pandemic is inevitable, real-time monitoring of transmission is vital for containing the spread of COVID-19. The main objective of this study was to report the real-time effective reproduction numbers (R(t)) and case fatality rates (CFR) in Europe. METHODS: Data for this study were obtained mainly from the World Health Organization website, up to March 9, 2020. R(t) were estimated by exponential growth rate (EG) and time-dependent (TD) methods. 'R0' package in R was employed to estimate R(t) by fitting the existing epidemic curve. Both the naïve CFR (nCFR) and adjusted CFR (aCFR) were estimated. RESULTS: With the EG method, R(t) was 3.27 (95% confidence interval (CI) 3.17-3.38) for Italy, 6.32 (95% CI 5.72-6.99) for France, 6.07 (95% CI 5.51-6.69) for Germany, and 5.08 (95% CI 4.51-5.74) for Spain. With the TD method, the R value for March 9 was 3.10 (95% CI 2.21-4.11) for Italy, 6.56 (95% CI 2.04-12.26) for France, 4.43 (95% CI 1.83-7.92) for Germany, and 3.95 (95% CI 0-10.19) for Spain. CONCLUSIONS: This study provides important findings on the early outbreak of COVID-19 in Europe. Due to the recent rapid increase in new cases of COVID-19, real-time monitoring of the transmissibility and mortality in Spain and France is a priority.