KELLY MCEVERS, HOST:
There are still a lot of questions about what or who caused serious health problems for American officials serving in Cuba. But Senator Marco Rubio says he hopes one thing became clear in a hearing he held today on the issue. There are 24 victims, and this is not simply a case of mass hysteria. NPR's Michele Kelemen reports.
MICHELE KELEMEN, BYLINE: It began as early as November 2016, first at diplomatic residences in Cuba, then at hotels. The State Department's medical director, Charles Rosenfarb, says embassy employees started reporting various symptoms from hearing lost to vertigo.
CHARLES ROSENFARB: They associated the onset of these symptoms to their exposures with unusual sounds or auditory sensations. Various descriptions were given - a high-pitched beam of sound, an incapacitating sound, a baffling sensation akin to driving with the windows partially open in a car or just an intense pressure in one ear.
KELEMEN: Ten of the 24 confirmed patients have since returned to work, he says. Some of the symptoms went away quickly, though some patients still have difficulty concentrating. And Rosenfarb brought in specialists on traumatic brain injuries to help. Cuba has denied any involvement, but acting Assistant Secretary of State Francisco Palmieri says Cuba has a responsibility to protect U.S. personnel.
FRANCISCO PALMIERI: Cuba's a security state. The Cuban government in general has a very tight lid on anything and everything that happens in that country.
KELEMEN: And he says Cuba has a long history of harassing U.S. diplomats. A diplomatic security official, Todd Brown, says initially that's what U.S. officials thought this was before coming to the conclusion that these were attacks. He wouldn't comment on an FBI report cited by The Associated Press that seems to rule out the idea that this was a sonic weapon. Brown had other suggestions when pressed by Senator Tom Udall.
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TODD BROWN: There's viral. There's ultrasound. You know, there's a range of things that the technical experts are looking at as, could this be a possibility?
TOM UDALL: So when you say viral, you're talking about somebody intentionally implanting a virus.
BROWN: That is - would not be ruled out. That could be a possibility.
KELEMEN: The only thing State Department officials have ruled out is that this is a case of mass hysteria. The Trump administration has dramatically scaled back its diplomatic presence in Cuba in response. Those who go now have to have baseline tests of their hearing and cognitive functions. And they are aware of the dangers, says Brown.
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BROWN: We prepare our personnel for levels of surveillance and levels of harassment. And movements are certainly restricted.
KELEMEN: Senator Marco Rubio says the State Department should have responded much earlier by setting up what's known as an accountability review board. Officials say they are doing that now and will notify Congress shortly. Michele Kelemen, NPR News, Washington.
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