GUANGZHOU, Dec. 21 (Xinhua) -- Chinese researchers have found that early and strict intervention policies can more effectively contain the spread of COVID-19.
A team led by reputed Chinese epidemiologist Zhong Nanshan and Jarvis Lab, a medical AI facility under Chinese tech giant Tencent, used policy data of 145 countries from the first half of 2020. With the data, they built a model to assess what would have happened if the intervention policies had not been implemented.
The result shows all interventions significantly decrease Rt after their implementation. The Rt (time-varying reproduction number) is the number of secondary infections produced by a single infection.
Most interventions took effect, reducing Rt about 7 to 14 days after implementation. The effects were strengthened to a maximum of around 30 percent reduction for Rt in 25 to 32 days. Among the intervention policies, school closing, workplace closing, and cancellation of public events demonstrated the strongest effect.
The researchers noted that longer and stricter intervention policies are more effective in the very early stage of the outbreak. There were more infected cases when intervention policies were implemented in the middle and late stages.
It is not the failure of epidemic control. It is because strict measures were not formulated until the epidemic had entered a stage of fast growth, said Sun Jichao of Tencent Jarvis Lab and first author of the research. He noted that interventions would be of little help in the middle and late stages of a COVID-19 outbreak.
The study has been published in the journal, Value in Health. Enditem