Nigeria's Ebola patient left the country on a medical evacuation flight to Switzerland on Monday morning, the health minister said.

The patient is the Ugandan-born wife of a Swiss diplomat based in Abuja and Nigeria's first Ebola case in more than a decade.

Health Minister Muhammad Ali Pate said in a post on X that the woman was clinically much improved, "stable, conscious, communicating, and her clinical laboratory test results closing towards baseline."

The patient was evacuated along with her spouse who has remained asymptomatic, Pate added.

The Swiss foreign ministry and Uganda's health ministry did not immediately respond to requests for comment.

Scientists have been trying to work out how Nigeria's Ebola case caught the Bundibugyo species of Ebola, amid conflicting accounts of whether she travelled to Democratic Republic of Congo, where the outbreak was announced in mid-May.

Switzerland said last week that she had not travelled to Congo, contradicting statements from Ugandan officials.

Her travel documents show she had not visited Congo, Africa CDC Director-General Jean Kaseya told Reuters in an interview.

Nigerian authorities have said she had been on holiday in Uganda and travelled through Entebbe airport on October 3.

One of the theories scientists are investigating is a potential link between the patient in Nigeria and the first case in Kenya, a man who had travelled from Congo and who also travelled through Entebbe airport on October 3.