The officers and their families are among 200 US officials and their kin around the world who have reportedly been affected by the mysterious illness.
Mr Burns, in his first interview on Thursday since being chosen to head the CIA by president Joe Biden in March, told the National Public Radio (NPR) about the agency’s efforts to bolster the investigation into the syndrome that was first reported five years ago.
He has formed a task force to find the reasons and origin of the illness, headed by a senior officer who helped track Osama bin Laden in 2011.
“There are probably a couple of hundred since Havana [was first spotted] in 2016. There are probably a couple of hundred incidents across the US government and across the globe,” he said, when asked how many officers were affected.
“Of those couple of hundred, there’s probably about 100 in which my colleagues, my officers and family members have been affected,” he added.
The illness has been known to cause serious brain damage and hearing loss in the more critical cases as well as dizziness and headaches, something that has led to several US officers taking early retirement.
Dozens of additional cases have been reported at US diplomatic offices in China and Russia. The Biden administration said last week that it was investigating reports of additional cases in Vienna. The syndrome is named after the Cuban capital as several cases were reported in the US embassy there in 2016.
Mr Burns said he was seriously considering the “very strong possibility” that the syndrome was borne out of intentional actions.
He also confirmed that his agency has given the responsibility to lead the task force to an unnamed senior officer who once led the operation to find Laden in Pakistan, confirming earlier US media reports.
“I am absolutely determined — and I’ve spent a great deal of time and energy on this in the four months that I’ve been CIA director — to get to the bottom of the question of what and who caused this,” Mr Burns told NPR.
“We’re throwing the very best we have at this issue, because it is not only a very serious issue for our colleagues, as it is for others across the US government, but it’s a profound obligation, I think, of any leader to take care of your people,” he further said.
“I’m certainly persuaded that what our officers and some family members, as well as other US government employees, have experienced is real, and it’s serious,” Mr Burns said.
He also added that there are a limited number of “potential suspects” with the means to carry out an action so widely across the globe. There have been theories of Russia carrying out these attacks against US officers, but Moscow has denied any involvement.
A potential microwave radiation was cited as the “most plausible” reason behind the illness by an earlier report from the National Academies of Sciences, Engineering and Medicine.
He also told the radio network that the agency has shortened the waiting period – from eight to two weeks – for CIA-affiliated personnel to be admitted and treated for the syndrome at the Walter Reed National Military Medical Centre.
“It’s a profound obligation, I think, of any leader to take care of your people and that is what I am determined to do,” Mr Burns said.