Spanish Health Minister Ana Mato has confirmed that a nurse who treated two victims of Ebola in Madrid has tested positive for the disease.
The nurse is said to be the first person in the current outbreak known to have contracted Ebola outside Africa.
The woman was part of the team that treated Spanish priests Manuel Garcia Viejo and Miguel Pajares, who both died of the virus, officials say.
Some 3,400 people have died in the outbreak – mostly in West Africa.
Meanwhile US President Barack Obama has said the White House is considering extra screening at US airports for people arriving from the worst-affected countries in West Africa.
He said the chances for an Ebola outbreak in the US were extremely low, but vowed to step up the pressure on larger countries to help with efforts to contain the disease.
It comes as the US tries to limit the spread from its first confirmed case, a Liberian in Dallas. Agency report
