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.