As the number of confirmed coronavirus cases continues to grow worldwide, more information regarding the virus' incubation period has begun to emerge. New research published in the journal Annals of Internal Medicine has shown that coronavirus symptoms take roughly five days to appear. While researchers still have much to learn about the novel coronavirus that causes COVID-19, this recent study has provided new insight into quarantine and self-isolation guidelines.
According to researchers, the majority of people infected with coronavirus will show symptoms within 11 and a half days after their initial exposure to the virus. That being said, researchers found that the median incubation period for coronavirus was five days. They also noted that individuals who have not developed any symptoms 12 days after exposure have a significantly lower risk of becoming infected.
"The median incubation period was estimated to be 5.1 days and 97.5% of those who develop symptoms will do so within 11.5 days of infection," the study noted. "These estimates imply that, under conservative assumptions, 101 out of every 10,000 cases will develop symptoms after 14 days of active monitoring or quarantine."
Researchers also noted that their findings were similar to the estimates and timeframes recommended by public health officials. "Our results support current proposals for the length of quarantine or active monitoring of persons potentially exposed to SARS-CoV-2, although longer monitoring periods might be justified in extreme cases," researchers noted in the study.
The Centers for Disease Control and Prevention (CDC), for example, has cautioned that coronavirus symptoms may appear anywhere from two to 14 days after exposure, and urge anyone exposed to someone confirmed to have COVID-19 to self-isolate or self-quarantine for 14 days. According to the CDC, symptoms of coronavirus include fever, cough, and shortness of breath.
While the flu can also fever in ill patients, its incubation period differs from that of coronavirus, according to NBC News. Typically, those infected with the flu will develop symptoms like fatigue, sudden fever, cough, and sore throat in one to four days.
To identify the incubation period for this new coronavirus, researchers from Johns Hopkins Bloomberg School of Public Health and the School of Public Health and Health Sciences at the University of Massachusetts, Amherst studied nearly 200 confirmed cases with identified exposure and symptom timeframes.
Lauer, S. A., Grantz, K. H., Bi, Q., Jones, F. K., Zheng, Q., Meredith, H. R., … Reich, N. G. (2020). The Incubation Period of Coronavirus Disease 2019 (COVID-19) From Publicly Reported Confirmed Cases: Estimation and Application. Annals of Internal Medicine. doi: 10.1101/2020.02.02.20020016
If you think you’re showing symptoms of coronavirus, which include fever, shortness of breath, and cough, call your doctor before going to get tested. If you’re anxious about the virus’s spread in your community, visit the CDC for up-to-date information and resources, or seek out mental health support. You can find all of Romper’s parents + coronavirus coverage here, and Bustle’s constantly updated, general “what to know about coronavirus” here.