Generalized logistic growth modeling of the COVID-19 outbreak in 29 provinces in China and in the rest of the world

Ke Wu; Didier Darcet; Qian Wang; Didier Sornette

is the (which was not peer-reviewed) The copyright holder for this preprint . https://doi.org/10.1101/2020.03.11.20034363 doi: medRxiv preprint Phase I (Jan 19 -Jan 24, 6 days): early stage outbreak. The data mainly reflects the situation before Jan 20, when no measures were implemented, or they were of limited scope. On Jan 19, Guangdong became the first province to declare a confirmed case outside Hubei in mainland China [22] . On Jan 20, with the speech of President Xi, all provinces started to react. As of Jan 24, 28 provinces reported confirmed cases with daily growth rates of confirmed cases ranging from 50% to more than 100%. to deploy the forces for the battle against the virus outbreak. In this phase, the growth rate of the number of confirmed cases in all provinces are declining from 50% to 10%+, with an exponentially decay rate of 0.157 for the aggregated data. At the provincial level, some provinces failed to see a continuous decrease of the growth rate and witnessed the incidence grow at a constant rate for a few days, implying exponential growth of the confirmed cases. These provinces include Jiangxi (~40% until Jan 30), Heilongjiang (~25% until Feb 5), Beijing (~15% until Feb 3), Shanghai (~20% until Jan 30), Yunnan (~75% until Jan 27), Hainan (~10% until Feb 5), Guizhou (~25% until Feb 1), Jilin (~30% until Feb 3). Some other provinces managed to decrease the growth rate exponentially during this period. As of Feb 1 st , 15 provinces had reached the peak of the incidence . CC-BY-NC-ND 4.0 International license It is made available under a author/funder, who has granted medRxiv a license to display the preprint in perpetuity.