Growth rate and acceleration analysis of the COVID-19 pandemic reveals the effect of public health measures in real time

Yuri Tani Utsunomiya; Adam Taiti Harth Utsunomiya; Rafaela Beatriz Pintor Torrecilha; Silvana Cassia Paulan; Marco Milanesi; Jose Fernando Garcia

(which was not peer-reviewed) The copyright holder for this preprint . https://doi.org/10.1101/2020.03.30.20047688 doi: medRxiv preprint FIGURE 5 | Growth rate and acceleration in Denmark, Estonia and Qatar. These three countries exhibited complex arrangements of growth stages. (a) On March 11 th 2020 (red dot), Denmark became the second European country to establish a lockdown. The country started decelerating new cases of COVID-19 two days after. (b) On March 13 th 2020 (red dot) a state of emergency was declared by the Estonian government, which imposed significant restrictions to travel and mass gatherings. Decline of growth rate was observed one day after, and deceleration started within 4 days. (c) Our analysis indicated that Qatar reached its peaking acceleration on March 9 th 2020 (red dot), the same day when Qatari officials had announced the closure of schools, nurseries, and universities, in addition to strong restrictions to traveling. One day after, the country registered a sudden spike in the number of cases (arrow). The days that followed were marked by a clear decline in acceleration and eventually deceleration of growth, which coincided with a succession of measures by the Qatari government that eventually led to significant restrictions to human movement. Although stationary growth was expected after deceleration, these three countries passed through a short linear phase and then regained acceleration, which initiated a new exponential phase. Estonia has further initiated a second deceleration stage on March 27 th 2020.