Mystery surrounds ailing diplomats in Cuba

WASHINGTON — There must be an answer.

Whatever is harming U.S. diplomats in Havana, it’s eluded the doctors, scientists and intelligence analysts scouring for answers. Investigators have chased many theories, including a sonic attack, electromagnetic weapon or flawed spying device.

Each explanation seems to fit parts of what’s happened, conflicting with others.

Suspicion has fallen on Cuba. But investigators also are examining whether another country such as Russia is to blame, more than a dozen U.S. officials familiar with the investigation told The Associated Press.

Those officials spoke on condition of anonymity because they weren’t authorized to publicly discuss the investigation. The AP also talked to scientists, physicians, acoustics and weapons experts, and others about the theories being pursued.

Of the 21 medically confirmed U.S. victims, some have permanent hearing loss or concussions, while others suffered nausea, headaches and ear-ringing. Some are struggling with concentration or common word recall, the AP has reported. Some felt vibrations or heard loud sounds mysteriously audible in only parts of rooms, and others heard nothing.

To solve the puzzle, investigators are sorting symptoms into categories.

SONIC DEVICE

The first signs pointed to a sonic attack. But what kind?

Some victims heard things — signs that the sounds were in the audible spectrum. Loud noise can harm hearing, especially highdecibel sounds that can trigger ear-ringing tinnitus, ruptured ear drums, even permanent hearing loss.

But others heard nothing, and still became ill. So investigators considered inaudible sound: infrasound, too low for humans to hear, and ultrasound, too high.

Infrasound often is experienced as vibration, like standing near a subwoofer. Some victims reported feeling vibrations.

The balance problems reported in Havana? Possibly explained by infrasound, which may stimulate cells in the ear’s vestibular system that controls balance, scientists say. But there’s little evidence infrasound can cause lasting damage once the sound stops.

If not infrasound, maybe ultrasound? At high-intensity, ultrasound can damage human tissue. That’s why doctors use it to destroy uterine fibroids and some tumors.

But ultrasound damage requires close contact.

THE CUBA THEORY

It was only natural that American suspicion started with Cuba.

The attacks happened on Cuban soil. The two countries routinely harassed each other’s diplomats over a half-century of enmity. Despite eased tensions over the past couple of years, distrust lingers.

Diplomats reported incidents in their homes and in hotels.

But what’s the motive? When symptoms emerged last November, Cuba was working feverishly with the U.S. to make progress on everything from internet access to immigration rules before President Barack Obama’s term ended. Officials still don’t understand why Havana would at the same time perpetrate attacks that could destroy its new relationship with Washington entirely.

Cuban President Raul Castro’s reaction deepened investigators’ skepticism, according to officials briefed on a rare, face-to-face discussion he had on the matter with America’s top envoy in Havana.

U.S. officials were surprised that Castro seemed genuinely rattled, and that Cuba offered to let the FBI come investigate.

THE OUTSIDERS

Who else would dare? U.S. investigators have focused on a group of usual suspects: Russia, Iran, North Korea, China, Venezuela.

Russia, in particular, has harassed American diplomats aggressively in recent years Moscow even has a plausible motive: driving a wedge between the communist island and “the West” — nations such as the United States and Canada. Russia also has advanced, hard-to-detect weaponry that much of the world lacks. None of the officials interviewed for this story pointed to any evidence linking Russia to the illnesses.