BARCELONA, Spain — Spain intensified efforts on Tuesday to contain any spread of Ebola from an infected health worker as the government came under increased pressure from the political opposition and the European Union.

The health worker, a nurse who has not been identified, was described as being in a stable condition. Her husband and two other people were quarantined, and monitoring was extended to another 50 who might have come into contact with her. The nurse contracted the illness while treating a Spanish missionary who was infected in Sierra Leone and flown to Carlos III Hospital in Madrid.

The nurse’s husband has shown no signs of having the disease but was isolated as a precaution, said Dr. Francisco Arnalich, head of internal medicine at Carlos III Hospital.