Nigeria's first confirmed case of Ebola since the outbreak in East Africa began in May is the wife of a diplomat who travelled to Uganda's capital for a holiday, the head of Africa's health agency has told the BBC.
The woman is originally from Uganda but based in Abuja, where she fell ill three days after arriving home in the Nigerian capital on 3 October, according to Dr Jean Kaseya from the Africa Centres for Disease Control and Prevention.
Nigeria's health minister has confirmed to the BBC the 42-year-old patient spent two and a half weeks in Kampala, adding that she also made a two-hour stopover in Ethiopia's capital on her return.
"She's stable, she's improving," Muhammad Ali Pate said.
The authorities were working to prevent the virus from spreading and had identified 44 people who had been in contact with the woman, who tested positive for Ebola on Tuesday, the minister said.
"Not all of them have been in close proximity. We cast the net wide so that we contain it as broadly as possible," Pate told the BBC.
Aviation Minister Festus Keyamo said 46 people - 44 who had come into contact with the woman at hospital and two people who worked in her home - had been banned from boarding flights.
Nigeria has also stepped up Ebola surveillance at its international airports following confirmation of its first case in more than a decade, he said.
Measures include health screenings, temperature checks, tracking travellers' movements and digital health declarations, Mr Keyamo said.
Neighbouring Cameroon has also stepped up surveillance at its airports and ports.
None of the contacts, who are now in isolation, are known to have developed symptoms, including the person the patient travelled with, the health minister said, adding that the woman had not travelled outside Abuja since landing.
Kaseya explained that the woman had first developed symptoms on 6 October when she had sought medical help.
"She went to the first hospital, a private hospital, thinking that she had malaria, and then she went to the second private hospital. She was admitted on the 11th," he told the BBC's Newshour programme.
Malaria is endemic in Nigeria and its symptoms - a high temperature, headaches, muscle aches, vomiting and or diarrhoea - are similar to those of Ebola.
After her condition failed to improve, public health authorities were alerted on Monday 19 October, Pate said.
Her diagnosis was confirmed the next day following three laboratory tests, he said. She has the same species of Ebola - Bundibugyo - as that behind the current outbreak in Democratic Republic of Congo, which has claimed at least 4,600 lives, with more than 9,500 cases recorded, the European Centre for Disease Prevention and Control reports .
The incubation period for Ebola ranges from two to 21 days, meaning those exposed to the virus may not become ill for several weeks.
Ebola is a rare but deadly disease caused by a virus. As the disease progresses, vomiting and diarrhoea develop and it can lead to organ failure. Some, but not all, patients develop internal and external bleeding.
The disease spreads from one person to another by contact with infected bodily fluids such as blood or vomit.
The Bundibugyo species of Ebola is relatively rare, with no approved vaccine or treatment - though trials are under way.
Shortly after the outbreak was announced, it was also reported in Uganda, where at least two people died. Uganda declared itself free of the disease in August after its last patient was discharged.
There have been conflicting accounts about the patient in Nigeria and her movements.
Pate and Kaseya's comments contradict a statement issued earlier by the Ugandan ministry of health, which described the woman as a Nigerian national who had gone to eastern DR Congo for business, only transiting through Uganda.
It insisted there were currently no confirmed active Ebola cases in the country and that the woman's passage through Uganda did not mean she had contracted the virus there.
Nigeria's health minister and the Africa CDC chief have sought to play down any tension.
Pate said Nigerian officials were working with Uganda, Ethiopia and the Africa CDC to establish the full facts.
"We respect our sister nation of Uganda," he said. "We have very strong solidarity, we are all in it together."
Kaseya also urged African countries to share information, saying this would help investigators trace the woman's movements and establish where she might have contracted the virus.
And he encouraged Western countries not to impose travel restrictions, saying "collaboration and solidarity" were the way to help stop the current outbreak.
The disease recently spread to Kenya, which has reported at least nine infections.
On Monday, the US advised its citizens to reconsider travel to Kenya because of health risks and raised its travel advisory level for the country.
In 2014, Nigeria successfully contained an Ebola outbreak , which had resulted in 20 confirmed cases and eight deaths.
Pate expressed confidence in the country's ability to repeat that success, citing strengthened disease surveillance, laboratories and thousands of trained epidemiologists.
"Nigeria has muscle memory that has been activated, but we are not fighting the past outbreak in the exactly the same way. We have to be vigilant," he said.
Additional reporting by Timothy Obiezu, Lucy Fleming and Paul Njie
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