More evidence shows COVID-19 has been spreading under the radar. This time, in France
Doctors in Paris say the coronavirus had been silently creeping around Europe a month before the official first known cases were diagnosed in the region, media outlets report.
The first two cases — with known travel to China — in France were reported Jan. 24, but after testing frozen samples from earlier patient records, doctors realized a man with no recent travel had the coronavirus in December, CNN reported.
The news adds to similar reports of ongoing community spread with no connection to China, where the outbreak began, in the United States that may have gone unnoticed for weeks before testing ramped up in the country.
“Identifying the first infected patient is of great epidemiological interest as it changes dramatically our knowledge regarding SARS-COV-2 and its spreading in the country,” a team of researchers said in their study published Sunday in the International Journal of Antimicrobial Agents. “Moreover, the absence of a link with China and the lack of recent travel suggest that the disease was already spreading among the French population at the end of December, 2019.”
The team studied records of people admitted to the hospital with flu-like symptoms between Dec. 2 and Jan. 16, which led them to a 42-year-old man who tested positive, according to CNN.
The man’s last reported travel was to Algeria in August, the outlet said.
Does this mean your tickle of a cough and fever at the start of the year could have been the coronavirus? It’s hard to say, according to experts.
“The initial introduction of the virus in the U.S. coincided with the peak of the flu season, so the symptoms you had, it would be difficult to untangle with flu,” Matteo Chinazzi, a research scientist at Northeastern University in Boston, told Live Science.
Chinazzi is part of a team that is tracking the spread of COVID-19 around the world. His model, by the Network Science Institute, suggests that about 28,000 people in cities such as New York, San Francisco and Seattle were already infected by March 1 while the focus was still on China, CNN said.
The novel coronavirus was first discovered in the U.S. in Snohomish County, Washington, in January, media outlets reported. The man had just returned from Wuhan, China.
The first two coronavirus-related deaths were later announced on Feb. 26 in Seattle.
But recent news of two people infected with the coronavirus who died Feb. 6 and Feb. 17 in their homes in the San Francisco Bay Area demoted the initial reports, and suggests the pathogen had been spreading long before anyone knew of its presence, Live Science reported.
It wasn’t until about a month later that the first case of community transmission, or spread between individuals with no known travel to China, in the U.S. was reported.
These cases were detected after the fact because at the time, testing was restricted to people who had known travel histories and who had exposure to someone who traveled.
The tiny differences in the genetic material of the virus collected from patient samples helped scientists connect the dots, according to a blog post by Trevor Bedford, an infectious disease researcher at the Fred Hutchinson Cancer Research Center in Seattle.
Mutations that happened over the course of five weeks revealed the virus had been spreading in the U.S. undetected because the genome from Wuhan differed from that of samples in Washington, the blog post said.
Studies have also shown that community spread in New York began in late January and came mostly from people who had traveled from Europe, not China, Live Science reported.
Scientists in Colorado said they believe the virus landed there around the last week of January, “about six weeks before the state even had the ability to test people for the disease,” according to The Colorado Sun.
Despite the progress made in tracking the virus, doing so remains difficult. Tests are still hard to come by and many mild and asymptomatic cases continue to go undiagnosed, experts say.
This story was originally published May 5, 2020 at 12:27 PM with the headline "More evidence shows COVID-19 has been spreading under the radar. This time, in France."
