French health officials are investigating three suspected cases of a deadly new respiratory virus related to Sars, while a man confirmed to have the virus remains in hospital.
Beatrice Degrugillers, a spokeswoman for the regional health agency in France's Nord-Pas-de-Calais region, said a nurse at the Douai hospital where the first patient was admitted in late April has herself been under observation since.
A doctor and a former hospital room-mate who had each been in contact with the first patient also remain in hospital. Test results are expected later.
On Wednesday, authorities announced that the 65-year-old Frenchman was France's first confirmed case of the novel coronavirus, which has killed 18 people and raised new public health concerns since being identified last year in the Middle East.