When has Covid-19 first appeared in France? As scientific experts from all over the world believe SARS-CoV-2 first broke out in December 2019 in a market in Wuhan, China, a study released this Saturday February 6, 2021, by French scientists in European Journal of Epidemiology refutes these observations.
According to works conducted by Pierre-Louis Institute of Epidemiologic and Public Health director Fabrice Carrat (INSERM, Sorbonne University), coronavirus or SARS-CoV-2 (the scientific name of the virus) rather dates back to November 2019. To come to such a surprising conclusion, the scientific method used by searchers from the professor’s team gives barely no room to doubts.
Helped by blood samples from “Constances” volunteers (200,000 people including in the biggest epidemiologic group in France since 2012), doctors first performed a quick test to find anti-SARS-CoV-2 type-G immunoglobulins. After a second and more delicate test – expected to prevent cross-check “false positive” – the surprise was huge: in the 9,144 blood samples studied between November 2019 and January 2020, 13 of them tested positive. As Pr. Carrat sums up to Le Monde, “these results suggest that the contamination rate in the French population in November and December was already one case for a thousand”.
Was the virus spreading from October or even September 2019 in France?
Before that, scientists have “started by assessing samples collected in January and February, and we found more positive than what we expected” INSERM epidemiologist Marie Zins told the daily. The investigation focused on the search for positive cases “starting from Fall”. According to the French health authorities, the first known case of Covid-19 was reported in late December 2019 in a patient hospitalized after severe pneumopathy in Seine-Saint-Denis.
Today, scientists use the same reasoning to periods prior to Fall 2019. “The question we currently ask is to know if the virus was already in France in September and why not even in August” Zins told Le Monde, before adding that her team is “looking for financing to carry out the necessary analyses”.
As to explaining the circulation of SARS-CoV-2 in French from November 2019, doctors venture hypotheses. “In more than half of cases, people have traveled or have been in contact with people who have been sick” Carrat says. “One of the cases have traveled for two months in Asia and returned in early December to France… Another one is a doctor, which is also a risk factor” the scientist says. To date, these theories cannot show the first strains of SARS-CoV-2 have started to spread in the Chinese province of Hubei yet.