Part of what makes coronavirus so contagious is its sneaky, asymptomatic incubation period. Until recently, the rule of thumb was that most cases became apparent between one and 14 days after exposure, with most cases manifesting themselves with symptoms sometimes around the fourth or fifth day. But one new study published in the journal Science Advances has determined that patients remain asymptomatic for longer than previously thought. As it turns out, patients are most likely to show their first symptoms that arrive on day eight.
While just 10 percent of the infected study subjects remained asymptomatic for a full 14 days, the researchers found that the median incubation period was 7.75 days, three to four days later than most previous estimates.
Of course, the incubation period of COVID can make a huge difference in whether we successfully contain the virus. “By giving health authorities a potentially more accurate figure for the incubation period, the results were able to inform guidelines for containment efforts such as quarantines and studies investigating the transmission of the disease,” the researchers shared in a press release.
The new study is probably more accurate than previous studies on the subject of incubation, as it has so far used the largest patient sample in such an analysis. As the researchers noted, “The few existing estimates of four to five days were based on small sample sizes, limited data, and self-reports that could be biased by the patient’s memory or judgment as an interviewer.” This study relied instead on public databases that recorded the dates of infection when they occurred, in an attempt to eliminate bias.
Finally, the researchers came to another striking conclusion: that it is possible that we underestimated the total incubation period of 14 days. The team found that the chance is between five and 10 percent that this is the case – meaning sick individuals could endanger others by ending their quarantines too soon. This is the reason why, if the data of the virus continues to explode, it is prudent on the side of caution: if you think they are exposed, do not wait for symptoms to confirm. When or when they occur does not affect your ability to spread coronavirus. And for more on asymptomatic cases, find out why 80 Percent of people in this age group are asymptomatic.
