DALLAS — They drew his blood, put tubes down his throat and wiped up his diarrhea. They analyzed his urine and wiped saliva from his lips, even after he had lost consciousness.

About 70 staff members at Texas Health Presbyterian Hospital were involved in the care of Thomas Eric Duncan after he was hospitalized, including a nurse now being treated for the same Ebola virus that killed the Liberian man who was visiting Dallas, according to medical records his family provided to The Associated Press.

The size of the medical team reflects the hospital’s intense effort to save Duncan’s life, but it also suggests that many other people could have been exposed to the virus during Duncan’s time in an isolation unit.

On Monday, the director of the Centers for Disease Control and Prevention said the infection of the nurse means the agency must broaden the pool of people getting close monitoring. Authorities have said they do not know how the nurse was infected, but they suspect some kind of breach in the hospital’s protocol.

The medical records given to the AP offer clues, both to what happened and who was involved, but the hospital said the CDC does not have them.

A CDC spokeswoman said the agency reviewed the medical records with Duncan’s care team and concluded that the documents were not helpful in identifying those who interacted directly with the patient.

“This is not something we can afford to experiment with. We need to get this right,” said Ruth McDermott-Levy, who directs the Center for Global and Public Health in Villanova University’s College of Nursing.

Until now, the CDC has been actively monitoring 48 people who might have had contact with Duncan after he fell ill with an infection but before he was put in isolation. The number included 10 people known to have contact and 38 who may have had contact, including people he was staying with and health care professionals who attended to him during an emergency room visit from which he was sent home. None is sick.