Santi Palacios, Associated Press
A woman walks past an advertising board calling for financial help to fight Ebola in Africa on Friday, Oct. 10, 2014, in Madrid, Spain.

MADRID — Spain's Ebola patient showed some marginal signs of recovery Sunday but European infectious diseases experts found shortcomings that need fixing in the Madrid hospital designated to deal with Ebola cases, officials said Sunday.

Assistant nurse Teresa Romero, who was infected with the Ebola in a Madrid hospital after having contact with two Spanish missionaries who later died from the virus, is showing signs of "slight improvement," a government statement said.

But the statement also said that Romero's prognosis remains serious and further complications can't be ruled out.

The statement added that a committee from the European Center for Disease Prevention and Control who visited Madrid's Carlos III hospital concluded that it wasn't suitable to meet emergencies such as an Ebola outbreak.

Fernando Simon, the Health Ministry's coordinator of emergency alerts, said one sign for optimism was that "the virus load" in Romero's bloodstream was decreasing.

Simon told a news conference at Prime Minister Mariano Rajoy's official residence that he had met with the two-man European communicable disease threats committee and been told of its concerns.

He said the area that needed to be improved was the airlocks leading into and out of the quarantine area at the Carlos III hospital.

"The airlocks were set up to deal with highly infectious situations, but what hadn't been foreseen was a need for bulky outfits to perform certain medical procedures in," Simon said.

He said the airlocks had been deemed too tight for such protective apparel.

Health authorities have said they suspected Romero may have become infected when she accidentally touched her face with a gloved hand while taking off protective gear in a small airlock.

Another Spanish nurse who had also treated a patient infected with the virus in Africa was released from the hospital late Saturday after twice testing negative for Ebola.

The patient, Manuel Garcia Viejo, died of Ebola on Sept. 25. He had been medical director of a Sierra Leone hospital for 12 years.