Medical research: Overall fatality risk of COVID-19 in Wuhan, China, estimated

The overall symptomatic case fatality risk of COVID-19 in Wuhan, China, was 1.4% as of 29 February 2020, according to a paper published in Nature Medicine. This figure is substantially lower than previously thought.

As of 29 February 2020, there were 79,394 confirmed cases of and 2,838 deaths from COVID-19 in mainland China, among which 48,557 and 2,169, respectively, occurred in Wuhan. A key public-health priority during the emergence of a new pathogen is estimating clinical severity. For patients and clinicians, this figure affects triage and diagnostic decision-making, especially in settings without ready access to laboratory testing or when surge capacity has been exceeded in hospitals.

Joseph Wu and colleagues updated their previously published disease transmission dynamics model with published and other publicly available information to determine a preliminary set of clinical-severity estimates, which could help guide clinical and public-health decision-making as the epidemic continues to spread globally. The authors determined that as of 29 February 2020, the symptomatic case-fatality risk — the probability of dying after developing symptoms — of COVID-19 in Wuhan was 1.4%. Compared to those aged 30-59 years, people below 30 years of age and above 59 years of age were 0.6 and 5.1 times more likely to die after developing symptoms, respectively. The authors also found that the risk of symptomatic infection increased with age — for example, about 4% per year among adults 30–60 years of age. These findings suggest the symptomatic case-fatality risk may be substantially lower than other estimates, particularly those based on crude case-fatality risk (proportion of deaths from the total number of cases), have indicated.