An analysis of publicly available data on infections from the new coronavirus, severe acute respiratory syndrome (SARS)-CoV-2, that causes the respiratory illness COVID-19 yielded an estimate of 5.1 days for the median disease incubation period, according to a new study led by researchers at Johns Hopkins Bloomberg School of Public Health. This median time from exposure to onset of symptoms suggests that the 14-day quarantine period used by the U.S. Centers for Disease Control and Prevention (CDC) for individuals with likely exposure to the coronavirus is reasonable.
The analysis suggests that about 97.5 percent of people who develop symptoms of SARS-CoV-2 infection will do so within 11.5 days of exposure. The researchers estimated that for every 10,000 individuals quarantined for 14 days, only about 101 would develop symptoms after being released from quarantine.
The findings were published online March 9 in the journal Annals of Internal Medicine. Dr. Justin Lessler, an associate professor in the Bloomberg School’s department of epidemiology, is the study’s senior author.
For the study, the researchers analyzed 181 cases from China and other countries that were detected prior to February 24, were reported in the media, and included likely dates of exposure and symptom onset. Most of the cases involved travel to or from Wuhan, China, the city at the center of the epidemic, or exposure to individuals who had been to Hubei, the province where Wuhan is the capital.Friday Letter Submission, Publish on March 13