Work by French researchers published on Saturday February 6 in the European Journal of Epidemiology undermines the hypothesis of the start of the epidemic on the Chinese market in Wuhan at the beginning of December 2019.
The department of Oise has long been considered the starting point for the spread of the virus with a “zero patient” identified “the second week” of January. The truth could be quite different.
Called upon by several clinical cases preceding the Covid-19 epidemic, doctors at the Albert-Schweitzer hospital in Colmar (Haut-Rhin) reanalyzed, in May, several hundred chest scans of patients admitted to their establishment from October 2019 , for severe pneumopathies. One of these patients, hospitalized on November 16, had lesions suggestive of Covid-19. A presence of the new coronavirus on French territory was therefore suspected on that date, but without analysis of biological samples, the hypothesis remained fragile.
Work by French researchers published on Saturday February 6 in the journal European Journal of Epidemiology dispel these doubts: they indicate, with a high level of evidence, that SARS-CoV-2 was already circulating in France in November 2019.
These researchers, led by Professor Fabrice Carrat, Director of the Pierre-Louis Institute for Epidemiology and Public Health (Inserm, Sorbonne University), analyzed 9,144 blood samples.
They first tested them with a rapid test that detected anti-SARS-CoV-2 type G immunoglobulins (IgG). This test being known to give “false positives”, the authors then performed a second test.
1 per 1,000 in December
Thus, out of the 9,144 samples analyzed, thirteen taken between November and January were found to be positive on both tests, including ten taken in November or December. “We started by analyzing samples taken in January and February, and we found many more positive than we expected., explains epidemiologist Marie Zins (Inserm, University of Paris) in the columns of World, principal investigator of the “Constances” cohort. So we looked to see if we found any in the fall. “
For the director of this study, M. Carrat, “These results suggest that from the months of November and December, the rate of contamination in the French population is already of the order of one case per thousand”.
–
