Experts say that revealing the transmission dynamics of COVID-19 and control efficiency is important for containing the spread of the virus.

By using a logistic growth model, Cheng, et al. (2021) estimated the transmission parameters of COVID-19 in China and six other countries (Republic of Korea, Iran, Italy, Spain, France and Germany). The transmission parameters represent the maximum daily increase rate in the early stages of the epidemic and the control efficiency under human intervention. The control efficiency was determined by the significant decrease of the daily increase rate in time and cumulative cases.

The researchers found the daily increase rate of cumulative cases of COVID-19 decreased significantly in both time and cumulative cases in all countries, but the decreasing trend was not further reduced in other countries except for China and Republic of Korea. The response of the daily increase rate to control measures was much earlier than the number of new cases.

The researchers say their results suggested that lockdown at the epicenter and social distancing effectively reduced the spread of COVID-19 in the early stage, but identification and isolation of patients, suspected cases and people with close contact at a community level is essential in further reduction of the daily increase rate of COVID-19.

Reference: Cheng C, et al. Modeling analysis reveals the transmission trend of COVID-19 and control efficiency of human intervention. BMC Infectious Diseases volume 21, Article number: 849 (2021)