The infection of two U.S. healthcare workers who cared for a dying Ebola patient in Dallas is challenging assumptions about how to protect Western medical workers who perform advanced, life-saving procedures that may increase their risk of exposure.

The U.S. Centers for Disease Control and Prevention says the infection of the two Dallas nurses likely occurred in the first few days of patient Thomas Duncan's admission to Texas Health Presbyterian Hospital in late September, and is investigating whether they correctly used personal protective gear such as gloves and gowns recommended by the agency.

Workers at the hospital also performed invasive procedures on Duncan such as inserting a breathing tube and filtering his blood through a dialysis machine, procedures that are unprecedented in the care of an Ebola patient in the last throes of the disease. But those same procedures make it more likely that a healthcare worker will come into contact with bodily fluids at their most infectious.  

"The thing we don't know is, was it truly a breakdown in personal protective equipment or was it because we were instrumenting the patient by intubation or dialysis?" said Dr Peter Hotez, a tropical disease expert at Baylor College of Medicine in Houston.

In West Africa, where the worst Ebola outbreak on record has killed more than 4,000 people, the use of advanced lifesaving measures is rarely an option. But in the United States, they are routine.

"We tend to go to the mat" in an effort to save patients, Hotez said. "Should we rethink whether we should be doing these life-saving measures? That is a question that medicine needs to address."

In most places in Africa, Ebola patients are only able to get supportive care, said CDC spokeswoman Abbigail Tumpey.

"Now that we're treating patients with Ebola in the U.S., we are using modern Western medicine that has not ever been used in field studies in Africa," she said. Treatment approaches such as dialysis and intubation "certainly have not been happening."

Tumpey said the CDC is now looking at the risks associated with these procedures.

"Because we don't have experience with treating patients with Ebola in U.S. hospitals where we have all of this technology and resources, it's possible that some of these procedures may put healthcare workers more at risk."

Dr. Jesse Goodman of Georgetown University Medical Center said that despite the fact Ebola has been around for decades, it is "entirely new to Western healthcare," and it is important to not be overly reliant on what has worked in prior outbreaks, especially when the healthcare systems are so dissimilar.

GREATER BENEFIT OR HARM?

To many, the questions Ebola is raising are reminiscent of the early days of caring for patients infected with the human immunodeficiency virus, or HIV, the virus that causes AIDS. Many of the safety protocols developed for blood-borne pathogens were developed through caring for AIDS patients.

But Ebola is different in some very important ways. It rapidly turns off the body's innate ability to fight viruses, multiplying unchecked as the disease progresses until patients' bodies are filled with billions of virus particles.

"Towards the last days of infection, that patient is basically a bag of virus," Hotez said.

When a patient with Ebola is reaching the stage in the disease where there is need for intubation or dialysis, the risk becomes greater to the healthcare worker than the benefit to the patient because they are "crashing" and near death.

"If it's that late a stage in the disease, the chances are that even if those are performed, the patient is already going to die," said Sean Kaufman, president of Behavioral-Based Improvement Solutions in Atlanta, who helps train hospital staff on safety measures.

Dr. Marc Napp, deputy chief medical officer and senior vice president for medical affairs at Mount Sinai Health System in New York, said that as a general rule "any patient that comes in, no matter what the condition, if they require certain medical therapy based upon clinical judgment and they want that therapy, we are obligated to provide it."

Napp said in the case of Ebola, there has not been any discussion about withholding life-saving treatments such as intubation for fear of harming staff members. But he said healthcare workers take risks all of the time.

"I'm a general surgeon. I've stuck myself with a needle. I've cut my finger on a broken bone from a person with hepatitis. We're exposed to this regularly," he said. "What's different here is there is the panic factor. It's a highly lethal infection.”