HealthDay News — The median incubation period for coronavirus disease 2019 (COVID-19) is estimated to be 5.1 days, according to a study published online March 10 in the Annals of Internal Medicine.
Stephen A. Lauer, Ph.D., from Johns Hopkins Bloomberg School of Public Health in Baltimore, and colleagues estimated the length of the incubation period of COVID-19 using data from news reports and press releases from provinces, regions, and countries outside Wuhan, China. Data were included for 181 confirmed cases with identifiable exposure and symptom-onset windows.
The researchers found that the median incubation period was estimated at 5.1 days; 97.5 percent of those who develop symptoms do so within 11.5 days of infection. One hundred one of 10,000 cases will develop symptoms after 14 days of active monitoring or quarantine under conservative assumptions.
“Although our results support current proposals for the length of quarantine or active monitoring of persons potentially exposed to SARS-CoV-2, longer monitoring periods might be justified in extreme cases,” the authors write. “Although it is essential to weigh the costs of extending active monitoring or quarantine against the potential or perceived costs of failing to identify a symptomatic case, there may be high-risk scenarios (for example, a health care worker who cared for a COVID-19 patient while not wearing personal protective equipment) where it could be prudent to extend the period of active monitoring.”