New Study Suggests COVID-19 Was Spreading in France in December

The conventional wisdom is that the SARS-CoV-2 virus began spreading in China in late 2019 and then spread to the rest of the world beginning in early 2020. However, a new study out of France indicates the virus had already arrived—and spread—in that country long before the start of the new year.

In a new article published in the International Journal of Antimicrobial Agents, investigators from the Paris Seine Saint-Denis Hospital Group in France report on the case of a man who was hospitalized in December 2019 with hemoptysis. The man was treated and discharged on Dec. 29, but after coronavirus disease 2019 (COVID-19) became a pandemic, hospital staff retrospectively tested a respiratory sample of the patient’s for SARS-CoV-2. It came back positive.

Prior to this study, it was thought that France did not have a case of COVID-19 until January.

“Based on this result, it appears that the COVID-19 epidemic started much earlier,” report Yves Cohen, MD, PhD, and colleagues.

On Jan. 24, France reported that 2 patients who had recently traveled to Wuhan, China, had tested positive for the disease. Given the direct connection to the Chinese outbreak and the lack of suspected cases prior to that date, public health officials there believed they may have identified the country’s “Patient Zeroes.”

In early April, however, Cohen and colleagues decided to dig deeper to evaluate that premise. The investigators took 14 samples from the hospital’s bank of respiratory samples taken from hospitalized patients. The chosen samples were from patients admitted between Dec. 2, 2019, and Jan. 16, 2020, who had influenza-like illness and ground glass opacity. Those samples underwent RT-PCR testing for the novel coronavirus, and one came back positive. The result was confirmed using the Gene Finder COVID-19 Plus RealAmp kit.

Notably, the positive patient—a 42-year-old man—had no apparent link to China. He was a longtime resident of France who worked as a fishmonger and had last visited his native Algeria in August 2019. The patient had a history of asthma and type 2 diabetes, and came to the hospital’s emergency ward with symptoms including hemoptysis, cough, headache, and fever. He was given antibiotics, responded favorably, and was discharged after 2 days.

Cohen said the patient’s travel history—or lack thereof—confounds the narrative that had previously prevailed about COVID-19 in France.

“[T]he 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,” they write.

As of May 5, the French government had tabulated more than 133,000 cases of COVID-19 and 25,000 deaths; however, the new study suggests the number of cases and deaths could be substantially higher.

“Furthermore, since these results change our understanding of the dynamic of the epidemic, it also means that several models used to predict the evolution and outcomes of the SARS-CoV-2 propagation might be based on biased data and would need to be readjusted to the actual profile of the epidemic,” Cohen and colleagues write.

The authors note a number of limitations, such as the fact that their medical records were not exhaustive and might be missing key information. However, they also note that their research is based on a small number of samples at a single hospital; therefore, the actual number of patients infected at the time was likely higher.