(AP Photo/David Goldman)

The Centers for Disease Control and Prevention need “considerable work” before the government’s top public health agency can achieve a culture of safety at its laboratories, according to a new report.

A review by a group of independent biosafety experts, whom the agency appointed after a series of high-profile lab accidents with anthrax and bird flu in 2014, found that CDC has made some progress. The director and executive staff “are clearly engaged and committed to promoting laboratory and research safety,” the authors write in a progress report posted Monday on the agency’s website.

Yet “considerable work toward achieving a culture of safety remains undone,” they write. They also note: “Morale has suffered in the last year because of these events and the public response to them.”

The experts, who interviewed more than 50 leaders and researchers at CDC, conclude that a reluctance to report lab incidents remains one of the most difficult issues.

“There is still apprehension about the possibility of retribution if staff, especially contractors, report accidents or safety concerns,” the report says. “Consequently, there is a need to work on building trust in the reporting process and resultant management response.”

The Atlanta-based agency has 153 laboratories and more than 2,000 scientists. CDC researchers, who work with some of the world’s most dangerous pathogens, had a leading role in fighting the Ebola epidemic that killed more than 7,500 people in Guinea, Liberia and Sierra Leone.

In 2014, the agency suffered serious safety breaches when anthrax, a deadly strain of bird flu and Ebola were mishandled in its labs in three separate incidents. No known infections or illnesses occurred as a result, but the incidents highlighted what CDC Director Tom Frieden told Congress was a too-narrow focus on response to specific events and a failure to spot a broad pattern of safety lapses.

Joseph Kanabrocki, an associate vice president for research safety at the University of Chicago, who co-chaired the review panel, said CDC has implemented some of the group’s recommendations. Others, such as how the agency assesses the biosafety risks of its research for lab employees and the general public, are more complicated and will likely take longer to put in place, he said.

“What needs fixing, you can’t simply flip a switch and have it fixed,” Kanabrocki said in an interview. He praised last September’s appointment of a new associate director for lab safety, longtime agency scientist Stephan Monroe, who reports directly to Frieden. The panel had urged creation of a new high-level safety position.

A big challenge for CDC is finding a way to bolster lab safety despite the time pressures of potential global health threats, Kanabrocki said. Unlike academia, many CDC labs are “on a clock.”

The agency’s blunders with dangerous pathogens parallel errors at other federal government labs, including at the National Institutes of Health, Food and Drug Administration and, most recently, a Pentagon lab that sent scores of live anthrax samples to facilities across the United States and overseas.

Frieden appointed the 11-member outside panel to investigate CDC’s lab safety in July 2014. Its first report, made public last March, was harshly critical and said safety was not part of CDC culture — particularly among more highly educated scientists and those working at the highest-security labs. The experts said they were “very concerned that the CDC is on the way to losing credibility.”

In addition to the new position to oversee lab safety, the panel also recommended more funding for lab-safety programs and training and a thorough review of risks associated with proposed experiments. The spending bill approved last month by Congress includes $13 million for that safety and training.

A new recommendation in the latest report calls for CDC to set up a database that would show which pathogens are being studied, where and by whom, across all of its 153 labs.

To address morale and encourage personnel to report accidents, CDC needs to do a better job explaining the steps already taken to improve lab safety and to protect public health.

Doing so “would help restore pride in some of the scientists working at CDC who have been discouraged by the safety challenges of the last year,” the report said. Instead, it explained, some staff feel the agency’s reaction has been to increase paperwork and that “signing a form does not necessarily lead to a fundamental improvement in safety culture.”

In a statement, agency spokesman Benjamin Haynes said the new report “recognizes that substantial progress has been made, acknowledges that culture change is a long and continuous process, and provides additional recommendations for further improvements.”