The first French Ebola patient is set to be flown home, as the World Bank warns the spiralling epidemic is threatening economic catastrophe in west Africa.
Doctors Without Borders, known by its French acronym MSF, said a female volunteer had contracted the killer virus while on assignment in Liberia.
France's health ministry said she "will be repatriated to Paris in conditions of maximum security in a dedicated air ambulance".
The Ebola outbreak in west Africa is the worst in history, with more than 2400 people already dead and quickening infection rates threatening to spiral out of control.
The World Bank on Wednesday warned that fear of the deadly virus is choking off economic activity in the worst-hit countries, with potentially "catastrophic" results.
MSF has played a major role in combating the epidemic, with more than 2000 staff members in the region including some 200 international workers.
But health bodies have warned that medical facilities are already so overwhelmed by new cases that they are having to turn people away to die on the streets.
MSF president Mego Terzian said the French Ebola patient, said to be in stable condition, was expected back in Paris on Thursday.
She is the first Western MSF worker to have caught the disease, though "unfortunately several African MSF colleagues have been affected", he added.
MSF gave no further details on the woman involved whom, they said, had been placed in isolation on Tuesday after showing symptoms of the deadly disease.
The United Nations Security Council is to hold an emergency session on Thursday to discuss ramping up the global aid response to the crisis.
US President Barack Obama on Tuesday pledged to send 3000 military personnel to west Africa to combat the epidemic, "the likes that we have not seen before".
