MADRID, Spain (AFP) — A Spanish nurse who is the first person known to have been infected with Ebola outside Africa is at “serious risk” of dying after her condition worsened yesterday, officials said.

Teresa Romero, 44, is “very ill and her life is at serious risk as a consequence of the virus,” Madrid’s regional president Ignacio Gonzalez told parliament.

A spokeswoman for the La Paz-Carlos III hospital where Romero is being treated told reporters: “Her clinical situation has deteriorated but I can’t provide more information,” on the patient’s request.

Romero helped treat two elderly Spanish missionaries who died after returning from west Africa with Ebola in August and September. She tested positive for the disease on Monday.

Her case has heightened concerns that the worst epidemic of Ebola on record could spread from west Africa, where it began late last year. It has since killed nearly 3,900 people, mostly in Liberia, Sierra Leone and Guinea.

She started to feel ill on September 29 but was not admitted to hospital until seven days later, during which time officials fear other people may have been exposed.

Health Minister Ana Mato said in a statement the government was working to “boost the protocol for tackling Ebola to exceed European recommendations”.

Romero had been receiving injections with antibodies extracted from the blood of Ebola survivors, hospital officials said.

Health officials said they were monitoring scores of other people — mostly health staff — who had been in contact with Romero. They will be under observation for 21 days, the maximum incubation period for Ebola.

Seven other people have been admitted to the hospital as a precaution, including Romero’s husband and several health workers, the hospital said, raising that figure by one on Thursday after another doctor was taken in for observation.

The nurse’s family dog — a mixed breed mutt named Excalibur — was put down on Wednesday as a precaution, triggering an uproar from animal rights activists.