In a case underscoring the perils of caring for Ebola patients, a nurse in Spain who cared for an Ebola patient has come down with the disease — the first known transmission outside West Africa during the current epidemic.

Her husband and a second nurse who treated the patient are now in quarantine, Spanish officials said Tuesday.

A man who arrived on a flight from Nigeria has also been quarantined, they said.

Public Health Director Mercedes Vinuesa told Parliament that authorities were making a list of other people who may have had contact with the nurse, who has not been publicly identified. The couple has no children.

The Health Ministry's chief coordinator for health alerts and emergencies, Fernando Simon, told Cadena SER radio that the nurse was in stable condition and her life not in any immediate danger. Health officials said she had no symptoms besides the fever.

News reports said she was 44.

Simon said her husband was "OK and relatively calm."

There was a low risk that some people in contact with the nurse could develop Ebola, Simon said, but he insisted this did not represent a public health threat. He disputed critics who said authorities were slow to react to the case.

The nurse, was hospitalized on Sunday, had helped treat Manuel Garcia Viejo, a Spanish priest returned from Sierra Leone who died Sept. 25 in another Madrid hospital designated for treating Ebola patients. She had changed a diaper for the patient and collected material from his room following his death. She then went on vacation.

Vinuesa said Spain had several therapies available and began applying them Monday, but gave no further details.

She had also assisted treating 75-year-old Spanish priest Miguel Pajares, also flown back to Spain from Liberia. He died after being treated with the experimental Ebola medicine ZMapp.

Garcia Viejo, who was in charge of the San Juan del Dios hospital in Lunsar, Sierra Leone, was not given the treatment because worldwide supplies ran out.

The virus that causes Ebola spreads only through direct contact with the bodily fluids of an infected person showing symptoms.

WHO estimates the latest Ebola outbreak has killed more than 3,400 people.