Coronavirus timeline takes a twist after early case identified in France
- New research shows disease was in France one month before first cases there were confirmed
- World Health Organisation asks countries to check whether Covid-19 was circulating earlier than they thought
The statement came after an analysis in France indicated a patient was infected with the coronavirus in Europe at the end of December – nearly a month before it was previously thought to have arrived on the continent.
Researchers identified a person who was hospitalised in France on December 27 by back-testing samples from a small number of patients with flu-like symptoms. The peer-reviewed findings suggest that the disease was already spreading among the French population at that time, the team said. It also indicates the virus may have entered other countries earlier than had been believed.
The report “gives a whole new picture on everything”, WHO spokesman Christian Lindmeier said at a UN briefing in Geneva on Tuesday, as he urged countries to investigate pneumonia cases from late last year to get a clearer picture of how the new disease spread.
Covid-19 was first reported by Chinese authorities to the WHO on December 31, but was not previously believed to have spread to Europe until January 24, when patients with links to the outbreak’s initial epicentre of Wuhan, China, were diagnosed in France.
The new French case is thought to be connected to a person who travelled from China before the virus was identified, the WHO said.
The timeline of the spread of the disease has been a moving target as the world has learned more about a virus that is thought to have spilled over into humans from bats, perhaps via an intermediary animal, adapting over a period of time before developing the capability to spread rapidly between humans and cause an outbreak.
French coronavirus strain did not come from China or Italy, scientists say
Sweden’s chief epidemiologist Anders Tegnell said on Tuesday in an interview with Sweden’s TT news agency that it would not be surprising if there were cases of coronavirus in the country as far back as November, brought there by travellers from Wuhan.
Also on Tuesday, reporters at The Palm Beach Post in Florida found that state health officials had documented at least 170 patients with Covid-19 that were reporting symptoms in January and February. The state’s first cases were not confirmed until early March.
But changing the timeline of an outbreak is not uncommon when tracking an emerging infectious disease, given that testing may not be available for novel diseases and new findings emerge alongside retrospective investigation, according to virologist Ian Mackay, an associate professor at the University of Queensland.
Coronavirus may have jumped to humans as early as October, study says
“It’s not surprising that we see cases occurring back in December,” said Mackay, referring to the findings in France and research published by The Lancet in January that pinned the earliest known case in China to December 1, in Wuhan.
“There’s no reason that there weren’t cases going on from that day forward, and no reason they weren’t hopping on planes and travelling around the world,” he said, adding that during the winter flu season it would be understandable that such cases would have been missed.
“The reality is so many cases of respiratory disease present, get swabbed, get tested, and there’s no positive result,” he said. “They’re not further investigated, they’re just told they’ve got a virus, so we would have missed [potential cases] unless we had some kind of signal flare, which was the WHO announcement that there was something new happening.”
Although it is unlikely that the virus had been spreading for “months and months in vast numbers all over the world unseen” before the identification of the outbreak in Wuhan, it would be interesting to know whether there were signs of the virus being exported from China before December, or elevated levels of viral pneumonia in different countries, he said.
Genome analysis has also shown that infection has spread through numerous routes in places including Europe and the United States, which banned travellers from China after January 31.
The British government’s chief scientific adviser Patrick Vallance on Tuesday said that many of Britain’s early cases were imported from Europe – most likely Italy and Spain – rather than China. Earlier genomic analyses of cases in New York have also determined that a majority of cases there came from Europe.
Other new research published on Tuesday used evolutionary genomic analysis to determine that the outbreak may have originally started as early as October 6.
These historical findings may not change day-to-day attempts to control the spread of the disease, but access to earlier viral samples can provide more information about the viral genome and how it has evolved, which can be important for developing drugs to combat it.
“The more we know about that information, the better prepared we’ll be for questions and answers around vaccines, antivirals, and understanding viral mutation in general,” Mackay said.
