After a Madrid nurse contracted the deadly Ebola virus, Spain's Prime Minister Mariano Rajoy appealed for calm on Wednesday and promised "transparency" over the scare. The event has sparked fierce criticism of national health safeguards.
Rajoy told parliament officials would "provide all the information possible to the public with total transparency", after the nurse became the first person to become infected with the disease outside of Africa.
"What we have to do right now is be vigilant but keep calm."
Four other people including the woman's husband have been hospitalized for observation since they were considered at risk of having the disease.
The government has set up a special commission to coordinate work between Spanish officials and liaise with European institutions, he said.
The European Commission on Tuesday demanded an explanation from Spain of how the nurse got infected in a specialized disease unit.
Rajoy said the top priority was to treat the patient and secondly to monitor people who had been in contact with her.
Officials would meanwhile "investigate what happened and why this contagion occurred", Rajoy added.
The leader of the opposition Socialists, Pedro Sanchez, questioning Rajoy in parliament, denounced the public spending cuts in healthcare during the recent years of economic crisis.
He said the cuts had forced healthcare staff to work in "extraordinarily difficult circumstances".
Health workers' unions on Tuesday complained that staff had not been adequately trained to treat Ebola patients safely.