The new coronavirus can spread from one person to another in less than a week, and over 10 percent of patients are infected by an asymptomatic person with COVID-19, a study published in Emerging Infectious Diseases shows.
Researchers studied more than 450 infection case reports from 93 cities in China. They calculated the time it took for symptoms to appear in two people with the virus: the person who infects another, and the second person who contracts the infection from the first person.
They found that in the chain of transmission for COVID-19, the time between cases was approximately four days.
Researchers also found that more than 1in 10 infections were contracted from people who had the virus but were not showing symptoms.
"This provides evidence that extensive control measures including isolation, quarantine, school closures, travel restrictions and cancellation of mass gatherings may be warranted," said Lauren Ancel Meyers, a professor of integrative biology at The University of Texas at Austin and a study author. "Asymptomatic transmission definitely makes containment more difficult."
But Dr. Meyers also said that as the pandemic continues, new data may cause these findings to change.