Coronavirus Incubation Period

What Is an Incubation Period?

The incubation period is the number of days between when you’re infected with something and when you might see symptoms. Health care professionals and government officials use this number to decide how long people need to stay away from others during an outbreak. It’s different for every condition.

If you’ve been around someone who has the new coronavirus that causes COVID-19, you’re at risk, too. That means you need to stay home until you know you’re in the clear. Health professionals call this self-quarantine. But when will you know whether you have the disease? The answer depends on the incubation period.

What Is the Incubation Period for the New Coronavirus?

To learn the incubation period for the coronavirus, researchers studied dozens of confirmed cases of COVID-19 reported between Jan. 4 and Feb. 24, 2020. These cases included only people who knew that they’d been around someone who was sick.

On average, symptoms showed up in the newly infected person about 5 days after contact. Rarely, symptoms appeared as soon as 2 days after exposure. Most people with symptoms had them by day 12. And most of the other ill people were sick by day 14. In rare cases, symptoms can show up after 14 days. Researchers think this happens with about 1 out of every 100 people.

Some people may have the coronavirus and never show symptoms. Others may not know that they have it because their symptoms are very mild. Current studies might not include the mildest cases, and the incubation period could be different for these.

When Is the Coronavirus the Most Contagious?

Researchers estimate that people who get infected with the coronavirus can spread it to others 2 to 3 days before symptoms start and are most contagious 1 to 2 days before they feel sick.

How Long Should I Quarantine After I’ve Been Exposed to the Coronavirus?

The CDC says that if you might have come into contact with the virus and have no symptoms, you should self-monitor. This means watching for signs such as fever, cough, and shortness of breath. Stay out of crowded places, keep at least 6 feet away from other people, and wear a cloth face mask when you have to go out.

If you traveled recently or know that you came into contact with someone who has COVID-19, you should self-quarantine. Stay home for 14 days. It’s very rare for symptoms to show up after that much time. Check your temperature twice a day, and watch for other symptoms. Stay away from other people, especially those who are at high risk of serious illness because of their age or another medical condition.

WebMD Medical Reference Reviewed by Brunilda Nazario, MD on April 20, 2020

Sources

SOURCES:

Nature Medicine: “Temporal dynamics in viral shedding and transmissibility of COVID-19.”

CDC: “Coronavirus Disease 2019 (COVID-19): Social Distancing, Quarantine, and Isolation," “Quick-Learn Lessons: Incubation Period.”

Annals of Internal Medicine: “The Incubation Period of Coronavirus Disease 2019 (COVID-19) From Publicly Reported Confirmed Cases: Estimation and Application.”

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