Some healthcare experts are bristling at the assertion by a top US health official that a "protocol breach" caused a Dallas nurse to be infected with Ebola while caring for a dying patient, saying the case instead shows how far the nation's hospitals are from adequately training staff to deal with the deadly virus.

Dr Thomas Frieden, director of the US Centers for Disease Control and Prevention, made the declaration on Sunday at a news conference and called for an investigation into how the unidentified nurse became infected while caring for Liberian national Thomas Eric Duncan, the first Ebola patient diagnosed in the US. Duncan died last week at Texas Health Presbyterian Hospital.

Healthcare and infection control experts said that hospital staff need to be coached through the stages of treating an Ebola patient, making sure they have the right safety equipment and know how to use it properly to prevent infection.

It was not immediately clear whether the Texas hospital prepared its staff with simulation drills before admitting Duncan, but a recent survey of nurses nationwide suggests few have been briefed on Ebola preparations. Officials at the hospital did not respond to requests for comment.

Some experts also question the CDC's assertion that any US hospital should be prepared to treat an Ebola patient as the outbreak ravaging West Africa begins to spread globally. Given the level of training required to do the job safely, US health authorities should consider designating a hospital in each region as the go-to facility for Ebola, they said.

"You don't scapegoat and blame when you have a disease outbreak," said Bonnie Castillo, a registered nurse and a disaster relief expert at National Nurses United, which serves as both a union and a professional association for US nurses. "We have a system failure. That is what we have to correct."

More than 4,000 people have died in the worst Ebola outbreak on record that began in West Africa in March.

In recent months, the CDC has published detailed guidelines on how to handle various aspects of Ebola, from lab specimens and infectious waste to the proper use of protective equipment.

How that information gets communicated to frontline workers, however, varies widely, Castillo said.

In many cases, hospitals "post something on a bulletin board referring workers and nurses to the CDC guidelines. That is not how you drill and practice and become expert," she said.

CDC spokesman Tom Skinner said the agency is still investigating the case of the Dallas nurse, but stressed that "meticulous adherence to protocols" is critical in handling Ebola. "One slight slip can result in someone becoming infected."

Skinner said the CDC is going to step up its education and training efforts on how to triage and handle patients, and may consider designating specific hospitals in each region as an Ebola treatment facility.

"We've been doing a lot over the past few months, but clearly there is more to do," he said. "The notion of possibly transporting patients diagnosed with Ebola to these hospitals is not something that is out of the question and is something we may look into." - Reuters