(Reuters) - The second U.S. patient to be diagnosed with the deadly Middle East Respiratory Syndrome (MERS) spent at least four hours in the public waiting room of a busy Florida emergency department before he was seen by a doctor, a hospital official said.

Almost eight more hours passed before staff at Orlando's Dr. P. Phillips Hospital determined the patient had traveled from Saudi Arabia, where he worked at a hospital, began to suspect his exposure to MERS and had him moved to an isolation room, the hospital's chief quality control officer said.

The official, Dr. Antonio Crespo, said that as of Tuesday, he had changed procedures in the emergency department of Dr. P. Phillips Hospital so that any patient who comes in with flu-like symptoms will be asked whether they traveled to Saudi Arabia or other countries experiencing MERS outbreaks.

"That is one of the learning lessons of this experience. Yes, we could have asked this sooner. I think we have created more awareness," Crespo told Reuters in an interview.

The extended window of time may have exposed hospital staff and other patients to the virus, which is responsible for a worsening outbreak in Saudi Arabia and is estimated to kill about a third of infected patients.

Florida officials said on Tuesday two healthcare workers who were in contact with the patient in the ER late last week had since developed flu-like symptoms and were being tested for MERS. Results are expected on Wednesday.

The possibility that the illness, which has no known treatment, was spreading raised new concerns about the ability of global health officials to contain it.

While the Orlando patient waited to be admitted, he was treated in a single room in the emergency department where healthcare workers wore gloves and gowns due to his diarrhea, but did not wear goggles and face masks appropriate for protecting them from the virus, Crespo said.

Florida officials said they were monitoring the health of 20 healthcare workers who had been in contact with the patient, including a doctor who had already left for Canada. They also were trying to track down nearly 100 people who may have overlapped with the patient at two Orlando medical facilities he visited.