Substantial undocumented infection facilitates the rapid dissemination of novel coronavirus (SARS-CoV-2)

Science. 2020 May 1;368(6490):489-493. doi: 10.1126/science.abb3221. Epub 2020 Mar 16.

Abstract

Estimation of the prevalence and contagiousness of undocumented novel coronavirus [severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2)] infections is critical for understanding the overall prevalence and pandemic potential of this disease. Here, we use observations of reported infection within China, in conjunction with mobility data, a networked dynamic metapopulation model, and Bayesian inference, to infer critical epidemiological characteristics associated with SARS-CoV-2, including the fraction of undocumented infections and their contagiousness. We estimate that 86% of all infections were undocumented [95% credible interval (CI): 82-90%] before the 23 January 2020 travel restrictions. The transmission rate of undocumented infections per person was 55% the transmission rate of documented infections (95% CI: 46-62%), yet, because of their greater numbers, undocumented infections were the source of 79% of the documented cases. These findings explain the rapid geographic spread of SARS-CoV-2 and indicate that containment of this virus will be particularly challenging.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Bayes Theorem
  • Betacoronavirus
  • China
  • Coronavirus Infections / diagnosis*
  • Coronavirus Infections / transmission*
  • Epidemiological Monitoring
  • Humans
  • Missed Diagnosis / statistics & numerical data*
  • Models, Theoretical*
  • Pandemics
  • Pneumonia, Viral / diagnosis*
  • Pneumonia, Viral / transmission*
  • Prevalence
  • Travel

Supplementary concepts

  • COVID-19
  • severe acute respiratory syndrome coronavirus 2