A Spanish nurse has contracted Ebola after treating two patients who died from the disease at a Madrid hospital, the government said Monday, in the first known case of transmission outside of Africa.

The 40-year-old began to feel ill on September 30 but did not go to hospital until Sunday, complaining of a fever.

Two tests have now confirmed that she has been infected with the deadly virus that has killed more than 3,400 people in west Africa.

Spanish health officials are scrambling to find out who she may have come into contact with, and are monitoring 30 people — including her co-workers and husband — closely for symptoms of the deadly disease.

The woman was part of a medical team at Madrid’s La Paz-Carlos III hospital that treated two elderly Spanish missionaries who died of Ebola shortly after they were repatriated from Africa.

She had gone on holiday the day after the second patient died on September 25, Madrid’s primary healthcare director, Antonio Alemany, said at a news conference, without specifying where she had travelled to.

The nurse, who is married without children, is now being treated in isolation at a hospital in Alcorcon, a southern Madrid suburb.

She is in a stable condition although still running a fever, Alemany added.