A Spanish nurse who caught Ebola at a Madrid hospital "mainly" stayed home after feeling the first symptoms of the deadly disease, her husband said in an interview published Wednesday.

Fears have spread in Spain after the government announced on Monday that the nurse had become the first person to contract the disease outside Africa.

She cared for two elderly Spanish missionaries who died from the virus following their return from west Africa.

The nurse, identified by Spanish media as Teresa Romero, a woman in her forties, began to feel ill on September 30 while on leave after treating the two missionaries, but was not admitted to hospital until five days later.

Asked where she was during this time, her husband Javier Limon told daily newspaper El Mundo: "At home, mainly."

Officials said they were trying to find out who she came into contact with before being isolated on Monday. They were monitoring 52 people -- mostly health staff.

The nurse, who is being treated in isolation at the Madrid hospital where she worked, told the newspaper she was feeling "a bit better".

Asked by the newspaper if she knew how she could have contracted the virus, she said: "I don't know what to say, I don't have any idea."

The nurse is believed to have contracted the virus while caring for Manuel Garcia Viejo, 69, a missionary who was repatriated from Sierra Leone and who died on September 25.

Officials said she visited his room twice, once to clean him and then to collect material after his death.

Asked by El Mundo if she had respected the strict protocol put in place for health care workers treating the missionary, she said: "I did."

Her husband, who has been placed in quarantine as a precaution, said he was feeling "perfectly well".

Daily newspaper ABC meanwhile reported that the nurse spent several hours in the waiting room of a hospital in Alcorcon, a southern Madrid suburb, where she went complaining of a fever before being diagnosed with Ebola.