Alliance for Pandemic Preparedness

February 4, 2020

Early epidemiological analysis of the 2019-nCoV outbreak based on a crowdsourced data

Category:

Topic:

Context: Based on current reports from China, the case fatality (%) among confirmed cases since the start of the epidemic is 2.1% (15% among “severe” cases; 1% among all confirmed and suspected cases).

  • Sun, et al. used crowdsourced data from a Chinese healthcare professional community network site and other publicly available data to provide information on demographics, hospitalization, and reporting lag during the period of Dec 2019 – Jan 2020. Case definitions are not specified.
  • They identified 288 apparently-hospitalized cases (200 in 5 provinces of mainland China; 88 international), including 39 fatalities (13.5%).
    • Cases were 63% male
    • Median age: 44 years of age, with a majority of case over 30 years.
      Seven (2.4%) cases were under 15 years (est. adjusted relative risk for age <15 yrs was 0.3).
    • Median age among those who died: 70 years. Two deaths (5%) occurred in persons <50 yrs.
    • Average lag in symptom onset to seeking care in China was 3 days, declining from 5 to 2 days before compared to after 18 January. In Hubei, the ~6 day average was probably affected by delays in the early Wuhan cases. Outside Hubei, the average was about 2 days; outside China, the average was same-day.
    • Average lag in hospitalization to report in China was 3 days, declining from 9 to 2 days before compared to after 18 January. In Hubei, the ~9 day average was probably affected by delays in the early Wuhan cases. Outside Hubei and internationally, the average was about 2 days.
    • Average lag in symptom onset to reporting was 5 days, ranging from 0-43 days.
    • Rapid growth of cases in China outside Hubei is reported as consistent with sustained transmission in those other areas.
  • Crowdsourced data appeared to capture more cases in China before the 18 Jan, when compared to national reporting; and slowed compared to national reporting after that.

Sun K, et al. (Feb 4, 2020). Early epidemiological analysis of the 2019-nCoV outbreak based on a crowdsourced data. Pre-Print downloaded on 4 Feb, 2020 from, https://www.medrxiv.org/content/10.1101/2020.01.31.20019935v1