An investigation of transmission control measures during the first 50 days of the COVID-19 epidemic in China

TLDR

China imposed a national emergency response on 23 January 2020 to restrict travel and enforce social distancing, but it remains unclear which measures were most effective. The authors conducted a quantitative analysis of control measures from 31 December 2019 to 19 February 2020, covering the Lunar New Year travel surge. Travel restrictions in and out of Wuhan were too late to stop spread to 262 cities within 28 days, but the epidemic peaked on 4 February 2020, suggesting that closing public transport, venues, and banning gatherings prevented hundreds of thousands of cases, and the decline was unlikely due to depletion of susceptibles, so easing measures could cause a resurgence. Tian et al.

Abstract

The most effective interventions By 23 January 2020, China had imposed a national emergency response to restrict travel and impose social distancing measures on its populace in an attempt to inhibit the transmission of severe acute respiratory syndrome–coronavirus 2 (SARS-CoV-2). However, which measures were most effective is uncertain. Tian et al. performed a quantitative analysis of the impact of control measures between 31 December 2019 and 19 February 2020, which encompasses the Lunar New Year period when millions of people traveled across China for family visits. Travel restrictions in and out of Wuhan were too late to prevent the spread of the virus to 262 cities within 28 days. However, the epidemic peaked in Hubei province on 4 February 2020, indicating that measures such as closing citywide public transport and entertainment venues and banning public gatherings combined to avert hundreds of thousands of cases of infection. It is unlikely that this decline happened because the supply of susceptible people was exhausted, so relaxing control measures could lead to a resurgence. Science , this issue p. 638