Well-Being Prevention & Cures

Coronavirus may incubate for longer than we thought–which means quarantines may have been too short


Story at a glance

  • The U.S. Centers for Disease Control and Prevention called it an interesting report, but are comfortable with 14-day quarantines.
  • The research noted one case in which a patient was found to have an incubation period as long as 24 days.
  • The average incubation period is around the three-day mark.

New research suggests the coronavirus could be capable of beating a 14-day quarantine, but health officials in the U.S. say they are comfortable with two-week quarantines at this time. 

China’s National Health Commission released a new study, which has yet to be peer-reviewed, that suggests the virus, known as COVID-19, could have an incubation period as long as 24 days in rare instances, with the average incubation period sitting around the three-day mark. An incubation period is the period of time between exposure to an infection and the appearance of the first symptoms. 

The research is based on a sample of 1,099 coronavirus patients selected from hundreds of hospitals throughout China. 

The study’s co-author, Dr. Zhong Nanshan, who is credited with helping combat SARS in 2003, reported that one patient in the sample was found to have an incubation period as long as 24 days. 

The study raises questions about the necessary length of quarantine periods for the virus, as U.S. officials have been ordering American evacuees from Wuhan, China, the epicenter of the outbreak, to be quarantined for 14 days. The 14-day mark is in accordance with known incubation periods. 

But the Centers for Disease Control and Prevention (CDC) is wary of the new finding. 

“I would say the incubation period is obviously really important to us as we look to make sure that we’re releasing these people safely from quarantine, but the abundance of data that is available is still consistent with our current stance, which is to use 14 days as the end of the incubation period,” Dr. Nancy Messonier, director of the CDC’s National Center for Immunization and Respiratory Diseases, said in a conference call Wednesday. 

So far, the virus has left more than 1,300 dead and nearly 60,000 infected in China. In the U.S., there have been 15 confirmed cases.