China’s health minister Ma Xiaowei made a startling statement Sunday about the Wuhan coronavirus: He said people can spread it before they become symptomatic.
“This is a game changer,” said Dr. William Schaffner, a longtime adviser to the US Centers for Disease Control and Prevention.
It’s much harder to contain a virus — to track down a patient’s contacts and quarantine them immediately — if the patient was spreading the disease for days or weeks before they even realized they had it.
“It means the infection is much more contagious than we originally thought,” said Schaffner, an infectious disease specialist at Vanderbilt University Medical Center. “This is worse than we anticipated.”
Ma didn’t explain why he thinks the virus can be spread before someone has symptoms. If the Chinese health minister is right — and there are those who doubt him — that means the five confirmed cases in the United States might have been infectious while traveling from Wuhan to Arizona, California, Illinois and Washington state, even if they had no symptoms at the time.
On Sunday, Dr. Nancy Messonnier, director of the US Centers for Disease Control and Prevention’s National Center for Immunization and Respiratory Diseases, said the risk to the American public for contracting this virus continues to be low.
“We at CDC don’t have clear evidence that patients are infectious before symptom onset, but we are actively investigating that possibility,” Messonnier said.
“We need to be preparing as if this is a pandemic, but I continue to hope that it is not,” she added.
The Wuhan coronavirus has killed more than 50 people in China and infected thousands there, and spread as far as the US, France and Canada.