SARS-COV-2, which causes COVID-19, has been found in a patient at a French hospital in December 2019, one month before the first confirmed case.

Electron micrograph of SARS-COV-2 virions in vitro

From Science Direct, published online May 3:

We report here a case of a patient hospitalized in December 2019 in our intensive care, of our hospital in the north of Paris, for hemoptysis with no etiological diagnosis and for which RT-PCR was performed retrospectively on the stored respiratory sample which confirmed the diagnosis of COVID-19 infection.

The first two cases previously reported in France were found January 24; both patients had a recent travel history to Wuhan, believed to be the source of the pandemic.  The clinical picture for patients with COVID-19 and seasonal influenza is virtually indistinguishable.  French scientists recently looked at samples taken from patients between December 2 and January 16, using stored swabs and specifically checking those patients who had tested negative for influenza and other common respiratory viruses.  The hospital involved has had a practice of storing samples taken from patients in a deep freeze for four years, looking forward to situations just like this, where they would need to go back and re-analyze old cases.

Of 124 samples, 14 had influenza-positive tests, 28 had other viruses, and one had a co-infection.  Of the other 80 patients, 66 were excluded because of their “COVID-19 non-typical medical record[s]”, leaving 14 with influenza-like illnesses.  Of these, one only, from December 27, 2019, was found to be positive for SARS-COV-2 on highly sensitive and specific testing.  This patient “presented to the emergency ward on December 27 2019 with hemoptysis, cough, headache and fever, evolving for 4 days.”  He was 42 years old and had type 2 diabetes mellitus and asthma.  One of his children had presented with similar (though milder) symptoms (a few days?) previously.

His medical reports were typical of COVID-19: CT scan of the lungs showed “ground glass” opacities on both sides.  He had a low lymphocyte count.  His C-reactive protein (a sign of acute inflammation) and fibrinogen (a sign of activated clotting system) levels were increased.  A culture from his sputum showed “no pathogens”.  He did well and was released from the hospital on December 29.  We can guess that he was not well isolated from the hospital staff or from family and friends, and that his infection was passed on.

This patient had no history of recent travel, and no known exposure to travellers from China.  He worked as a “fishmonger”.  His case was added to the known total of over 86,000 infections in France, 55% of which were passed on from persons unknown.

The highly restrictive nature of the case-finding procedure in this case suggests that there were many more patients who presented with milder illnesses during December 2019 in France, who would have been found to have COVID-19 if they were tested.  We can only guess that an unknown person from Wuhan, China brought SARS-COV-2 to France in early or mid-December.  That person may have been asymptomatic, as the paper cites a figure of 18-23% of patients without symptoms; other researchers have suggested that this proportion is much larger.

Further retrospective analysis or surveillance may reveal who caused this spread or when it happened.  Until then, we speculate that the virus was circulating as early as September 2019 (according to some researchers) or as late as early December.  Just where it appeared in humans, and when, will probably never be known for certain; these dates may be the closest we will come.