Results

Detected confirmed cases
Between 10 January and 24 January (period until confirmation of the first cases in France), nine possible cases were identified in France; among them, three cases were confirmed with COVID-19.
Case 1 was a 48-year-old male patient living in France. He was travelling for professional reasons in China in various cities including Wuhan when he experienced his first symptoms (fever, headaches and cough) on 16 January. He flew back to Bordeaux, France on 22 January via Shanghai, Qingdao and Paris Charles de Gaulle airports. He reported wearing a mask during the flights. He sought medical attention from a general practitioner on 23 January, where he was suspected of COVID-19, and was subsequently transferred to the regional referring hospital in Bordeaux, isolated and sampled for laboratory confirmation of SARS-CoV-2 infection. Infection was confirmed on 24 January by the National Reference Centre (Figure). Case 1 tested positive only for the E gene target when using the Charité procedure [4] and was positive for all four RdRp-IP targets with threshold cycles (Ct) in good agreement with those obtained for the E gene target.
Figure  Timeline of travel, onset of illness and close contacts of confirmed cases of COVID-19, France, January 2020 (n = 3)
ED: emergency department; GP: general practitioner; ICU: intensive care unit; ID: infectious diseases. The patient arrived in Wuhan on 13 January, did not report any visit to markets, exposure to live animals or contact with sick persons during his stay. No detailed information is available about the circumstances of exposure, apart from a visit to family members and friends on 15 January.
Case 2 was a 31-year-old Chinese male tourist who had left Wuhan on 18 January and arrived in Paris on 19 January. He developed fever, chills, fatigue, conjunctivitis and cough on 19 January. Case 3 was a 30-year-old Chinese female tourist who travelled with Case 2. She developed fever, chills, fatigue and cough on 23 January. On 24 January, they were advised by the Chinese embassy to seek medical attention at the national hotline (SAMU-centre 15) and were immediately transferred to a regional referring hospital, isolated and sampled for laboratory confirmation of COVID-19. Infection with SARS-CoV-2 was confirmed on 24 January for both of them by the National Reference Centre (Figure). Cases 2 and 3 were positive by RT-PCR for all targets of the Charité procedure [4] (RdRp Pan Sarbeco and 2019-nCov probes; E; N) as well for the four RdRp-IP targets with Ct values in good agreement with those obtained for the E gene target.
The condition of the male patient deteriorated on 29 January and he was admitted to the intensive care unit (ICU) the same day. He stayed 72 h in the ICU for non-invasive oxygen therapy and was transferred back to infectious diseases ward on 31 January.
Neither of the two cases reported any visit to markets, exposure to live animals or contact with sick persons during the 14 days before symptom onset. Both visited a hospital in Wuhan on 16 January for an unrelated medical condition in Case 3 (Figure).
As at 12 February, Case 1 was afebrile and symptomatic with a persistent cough. Cases 2 and 3 were not symptomatic any more and were discharged from hospital on 12 February.
As soon as the infection with SARS-CoV-2 was confirmed for the three cases on 24 January, this information was immediately released through a press conference held by the French Minister of Health and the Chief Medical Officer. Daily public communication on the state of the investigations around the cases was subsequently implemented by the Ministry of Health. Daily updates were also published on the SpF website.
The three cases were notified to the European Commission via the Early Warning and Response System (EWRS) on 26 January, and to the European Center for Disease Prevention and Control (ECDC) via the European Surveillance System (TESSy) on 28 January.

Contact and co-exposition tracing
No co-exposed person was identified for Case 1. Two contacts were evaluated at low risk of infection, the taxi driver who drove the case from the airport to his home (30-min drive) and the general practitioner who took care of the patient before wearing appropriate personal protection equipment (3-min non-close contact). Seventeen contacts were evaluated at moderate/high risk of infection. Four of them shared the same waiting room in the general practitioner’s office while Case 1 was coughing, seated ca 1–1.5 m away from the case during 5–30 min. The other 13 contacts were the persons sitting in the two seats around Case 1 in the Shanghai–Paris and Paris–Bordeaux flights (Figure). They were considered at moderate risk of exposure despite the fact that Case 1 reported wearing a mask during the whole flight; this was based on the length of one of the flights (> 6 h) and the fact that it was unclear whether or not Case 1 removed his mask during short periods (e.g. meals) and kept the same mask during the whole flights. None of the contacts of the Shanghai–Paris flight were French nationals and their contact tracing was referred to their home countries’ health authorities. All other identified contacts were evaluated at negligible risk of infection because the contacts were short and/or distant in public settings and did not imply face-to-face conversations or because appropriate personal protective equipment (PPE) was worn by the healthcare personnel who took care of the patient, including those involved in the transfer from the general practitioner to the referring hospital.
Cases 2 and 3 stayed together and shared the same activities during their stay in Paris, and therefore shared the same contacts from 23 January (date of illness onset for Case 3). Three contacts were evaluated at low risk of infection: the two owners of the apartment rented by the couple and a department store employee with whom Case 2 reported a distant (> 1 m) contact during around 20 min on 22 January. The apartment owner’s child who visited Cases 2 and 3 and was hugged by them was evaluated at moderate/high risk of infection (Figure). All other identified contacts were evaluated at negligible risk of infection, as contacts were short and distant in public settings such as department stores and did not imply face-to-face conversations or because appropriate PPE was worn by the healthcare personnel who took care of the patients.
Follow-up of the identified contacts was initiated according to the COVID-19 procedure (Table). As at 2 February, two contacts have been classified as possible cases since the implementation of the follow-up: A person sitting two seats away from Case 1 during the Paris–Bordeaux flight, and therefore identified as a moderate/high risk contact, developed respiratory symptoms on 27 January and was classified as a possible case on 31 January and was subsequently excluded following negative RT-PCR results. Infection with SARS-CoV-2 was excluded on the same day. A radiology assistant who took care of both Cases 2 and 3 developed respiratory symptoms on 30 January and was classified as a possible case on 2 February. This person had been classified as at negligible risk of exposure, because she wore appropriate PPE during the whole procedure. Infection with SARS-CoV-2 was excluded on 2 February.
Follow-up of the contacts ended on 6 February. No identified contact of the three cases has been confirmed with COVID-19.