Three people are being tested for Ebola in Madrid, Copenhagen and Connecticut, after fears they have contracted the virus.
In Denmark, a patient - believed to be an aid worker with the organisation Médecins Sans Frontières - has been admitted to hospital after he arrived into Copenhagen from West Africa showing signs of the virus.
In America, a Yale University student who recently returned from Liberia is also being tested.
Earlier today, an Air France plane was isolated at an airport in Madrid after a patient was reported to have a fever and shivers.
The situation is being treated as a suspected case of Ebola, a health ministry official was quoted as saying.
There were 183 passengers on the flight from Paris, according to local officials and media reports.
Airports operator Aena and Air France said in separate statements that a passenger on Air France 1300 from Nigeria, via the French capital, had started shaking during the flight.
Air France said the other passengers got off the plane, which will be disinfected.
The return flight has been cancelled.
Spanish response
Spain's government has stepped up its response to suspected Ebola cases in the wake of a health scare when a nurse in Madrid became the first person outside Africa to become infected with the deadly virus.
Teresa Romero, was diagnosed with the virus last week and is still seriously ill but stable. She cared for two infected priests repatriated from West Africa who later died.
A person who had been in contact with Ms Romero and was being monitored remotely for signs of the disease would be hospitalised, after developing a fever, Spanish authorities said.
The person was one of 68 considered to have a low risk of catching Ebola, and who have to check their temperature regularly from home.
Another 15 people, including Ms Romero's husband, are still under observation in Madrid's Carlos III hospital where she is also being treated, but have displayed no symptoms.
Meanwhile, the European Union has said it will launch an "immediate" review of exit screening in African countries hit by Ebola.
EU health chief Tonio Borg said the bloc, along with the World Health Organisation (WHO), will look into "conflicting reports" about whether the screening in Liberia, Sierra Leone or Guinea is good enough and will decide whether to strengthen controls.
The death toll from the outbreak will rise to more than 4,500 this week, according to a top official from the WHO.
Dr Isabelle Nuttall, director of the organisation's global capacities, alert and response, said cases are doubling every four weeks.
The WHO will also send teams of experts to test Ebola-preparedness measures at Ivory Coast and Mali's border with the countries affected by the virus.
Originally posted at 2:43 pm
