Exponential damping key to successful containment of COVID-19 outbreak

Feng Zhang; Jinmei Zhang; Menglan Cao; Yong Zhang; Cang Hui

the carrying capacity of the number of infections (set as 70% of the entire population, but please note, in most cases the final number of infections is much lower than , so we have essentially ignored its effect on the outbreak). We estimated the transmission rate as ( + 1/2) = ln� ( + 1)� − ln( ( )), where is measured in days. Notably, ( )/ > 0 represents the acceleration of the epidemic spread, while ( )/ < 0 the deceleration and damping dynamics. We define the damping rate ( ) as the rate of the exponential decline in the transmission rate ( ); that is, ( ) = − + . An effective control measure should, arguably, result in the deceleration of the spread at a high damping rate (large positive ), while inadequate control measures could lead to a low damping rate (small positive close to zero) and even the acceleration of the spread ( < 0). The solution to the above differential equation is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.