Alliance for Pandemic Preparedness

February 4, 2020

The incubation period of 2019-nCoV from publicly reported confirmed cases: estimation and application

Category:

Topic:

  • Incubation periods were assessed by Lauer, et al. based on 101 confirmed cases with identifiable exposure windows from outside Hubei province (other parts of China plus globally). Case were 62% male with a mean age of 52 years. 
    • Mean incubation period: 5.2 days (95% CI, 4.4, 6.0 days)
    • 95% of persons developed symptoms within 10.5 days (95% CI, 7.3, 15.3 days)
    • 64/10,000 cases may develop symptoms after 14 days (<1%)
    • Median incubation time assessing fever only: 5.7 days, with 97.5% of persons experiencing fever within 11.4 days (95% CI: 6.1, 17.8 days)
  • A subset of patients with symptom onset outside a facility had a mean time of 2.7 days from symptoms to hospitalization. [Note: Consistent with Sun, et al., below]
  • Incubation periods appear on average almost a day shorter in China than elsewhere, possibly due to a bias that persons able to travel out of China tended to have longer incubation periods.
  • These estimates are generally consistent with earlier estimates and those for SARS and MERS, though longer than the roughly 3-day period seen for other non-SARS human coronaviruses.

Lauer SA, et al. (Feb 4, 2020). The incubation period of 2019-nCoV from publicly reported confirmed cases: estimation and application. Pre-Print downloaded on 4 Feb, 2020 from, https://www.medrxiv.org/content/10.1101/2020.02.02.20020016v1