DALLAS — Federal health officials on Monday urged the nation's hospitals to "think Ebola" and launched a review of procedures for treating infected patients, while the World Health Organization called the outbreak "the most severe, acute health emergency seen in modern times."
Public-health authorities also intensified their monitoring of Dallas hospital workers who cared for a man who died of Ebola. Their stepped-up efforts came a day after a nurse was tested positive for the virus.
The nurse, who was wearing protective gear when she took care of Thomas Eric Duncan, became the first person to contract the disease within the United States.
Centers for Disease Control and Prevention Director Tom Frieden said he would not be surprised if another hospital worker who cared for Duncan becomes ill because Ebola patients become more contagious as the disease progresses. The CDC now is monitoring all hospital workers who treated Duncan and planned to "double down" on training and outreach on how to safely treat Ebola patients, Frieden said.
When asked how many health care workers are being checked, Frieden said officials "don't have a number."
Health officials have relied on a 'self-monitoring' system when it comes to U.S. health care workers who care for isolated Ebola patients and wear recommended protective equipment. They expect workers to report any potential exposures to the virus and watch themselves for symptoms.
Besides the workers, health officials continue to track 48 people who were in contact before Duncan was admitted to the hospital and placed in isolation. They are monitoring one person the nurse was in contact with while she was in an infectious state.
None has exhibited symptoms, Frieden said.
The case involving the infected nurse raised questions about assurances by American health officials that the disease will be contained and that any U.S. hospital should be able to treat it.
Frieden has said a breach of protocol led to the nurse's infection, but officials are not sure what went wrong. The nurse, who has not been identified, has not been able to point to any specific breach.
President Barack Obama asked the CDC to investigate.
Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases was asked on ABC's "Good Morning America" if federal health authorities should consider requiring that Ebola patients be sent only to highly specialized "containment" hospitals.
"That is something that should be seriously considered," Fauci said.
Dallas police barred entry to the nurse's apartment complex Sunday. Officers also knocked on doors, made automated phone calls and passed out fliers to notify people within a four-block radius about the situation, although authorities assured residents the risk was confined to those who have had close contact with the two Ebola patients.
The nurse wore a gown, gloves, mask and face shield while she cared for Duncan during his second visit to Texas Health Presbyterian Hospital, said Dr. Daniel Varga of Texas Health Resources, which runs the hospital.
Duncan, who arrived in the U.S. from Liberia Sept. 20, first sought medical care for fever and abdominal pain Sept. 25. He told a nurse he had traveled from Africa, but he was sent home. He returned Sept. 28 and was placed in isolation because of suspected Ebola. He died last week.
The health care worker reported a fever Friday night, Varga said.
Among the things the CDC will investigate is how the workers took off protective gear, because removing it incorrectly can lead to contamination. Investigators will also look at dialysis and intubation — the insertion of a breathing tube in a patient's airway. Both procedures have the potential to spread the virus.
Fauci said on CNN that the CDC is examining procedures like dialysis to see if they "heighten greatly" the risk of health care workers contracting Ebola. He suggested that in cases where the patient has deteriorated to the point where he or she cannot be saved, such high-risk procedures should not be done.
Every emergency room needs to be prepared to take action because no one can control where an Ebola patient might show up, said Dr. Dennis Maki, University of Wisconsin-Madison infectious disease specialist and former head of hospital infection control.
However, only large hospitals such as those affiliated with major universities truly have the equipment and manpower to deal with Ebola correctly, Maki said.
Health care workers treating Ebola patients are among the most vulnerable, even when wearing protective gear.
Nurses at many hospitals "are alarmed at the inadequate preparation they see," read a statement from Rose Ann DeMoro, executive director of the National Nurses United union.
More than 370 health care workers in West Africa have fallen ill or died since the epidemic began earlier this year.
Officials said there is a dog in the nurse's apartment, and they are trying to find a location to monitor and care for the animal. They do not believe the pet has any signs of Ebola. A dog belonging to an infected Spanish nurse was euthanized, drawing thousands of complaints.
In a statement read to a regional health conference in the Philippine capital of Manila, WHO Director-General Margaret Chan said staff members of the global health organization "are very well aware that fear of infection has spread around the world much faster than the virus."
Ebola has killed more than 4,000 people, mostly in the West African countries of Liberia, Sierra Leone and Guinea, according to WHO figures published last week.
The virus spreads through close contact with a symptomatic person's bodily fluids, such as blood, sweat, vomit, feces, urine, saliva or semen.
Associated Press Medical Writer Mike Stobbe in New York contributed to this story.