Among news on the spread of the current epidemic of coronavirus it can be difficult to find science-based advice, since much of the information is just cautionary or absolutely wrong.
Now, the latest research at Johns Hopkins University has shown that COVID-19 has an average coronavirus incubation period of 5,1 days, meaning the CDC-recommended 14-day quarantine period is well modulated.
Health officials must make important decisions based on limited information, and it is always good that that decision is backed up by science.
The Johns Hopkins team investigated 181 cases of COVID-19 outside of Hubei province in China before February 24 this year.
By recording the time of possible exposure, the onset of symptoms, the onset of fever and the detection by the authorities for each case, the team created a distribution model of the coronavirus incubation period.
What is the incubation period
Put simply, the incubation period is the time between exposure to the disease and the onset of symptoms. This time frame usually precedes the contagious period, in which the infected patient is likely to pass the disease on to others.
We still don't know how contagious coronavirus is when people show no symptoms: however, there have been some reports of people passing the virus without showing any symptoms.
That said, as with other coronaviruses (such as the common cold), you are much more likely to pass the virus to someone else when you have symptoms, coughing or sneezing.
The distribution of coronavirus incubation data
The Johns Hopkins team found that less than 2,5% of those infected would show symptoms within 2,2 days; the median estimated incubation period is 5,1 days; and the 97,5% will show symptoms for up to 11,5 days after exposure.
Based on our analysis of publicly available data, the current 14-day recommendation for active monitoring or quarantine is reasonableJustin Lessler, epidemiologist at the J. Hopkins School of Public Health.
This type of research is incredibly useful for infectious disease specialists who are making policy decisions for the coronavirus.
It was feared that the quarantine period was not long enough, after other teams of researchers had discovered cases of incubation periods lasting up to 19 and 24 days.
Extrapolating from 181 cases, the Johns Hopkins team estimated that for every 10.000 people quarantined for 14 days, about 101 would develop symptoms after exiting quarantine.
Learn about coronavirus incubation for better quarantine policies
Further research with larger groups of people will need to be done to confirm whether longer incubation periods could cause problems with our current quarantine policies.
And for the rest of us, until a vaccine is created, the best way to fight the virus is to stay calm, wash your hands (for 20 seconds!) And most importantly stay home.
The research was published on Annals of Internal Medicine.