Pulsed Energy? Ultrasound? What Caused Mystery Illness "Havana Syndrome"

Intense directed energy from an external source could have caused some cases of the debilitating so-called "Havana syndrome" among US diplomats, US intelligence said Wednesday, supporting the possibility of deliberate attacks.

A panel of technological and medical experts convened by the US intelligence community found that pulsed electromagnetic energy and ultrasound, delivered from close distances, could cause the unique mix of symptoms in a certain number of what are officially called anomalous health incidents (AHIs).

They said the technology exists to cause the uncommon mix of ear pains, vertigo, nausea and other symptoms first reported by US officials working in Havana, Cuba in 2016.

Out of hundreds of cases reported,  "a subset of AHIs cannot be easily explained by known environmental or medical conditions and could be due to external stimuli," said an unclassified summary of the experts' report, released by the US director of national intelligence.

The experts said it is possible to create concealable devices that, using moderate amounts of energy, would direct electromagnetic energy or ultrasound waves to cause damage in a targeted person.

Focused only on the possible causes of AHI, the experts did not say whether such devices exist. Nor did they conclude whether such attacks did take place, or suggest who could have been behind them.

But their report pushed back at some claims rejecting the technological possibility of AHI attacks.

Over the past five years US officials and family members based in numerous countries around the world have reported physical ailments that fell in the category of AHI.

The Central Intelligence Agency recently found that all but about two dozen of some 1,000 reported AHI cases had conventional medical or environmental explanations.

But for those two dozen, there was no explanation.

According to a senior intelligence official, the CIA concluded it was "unlikely" that a foreign actor had conducted a "sustained, worldwide" campaign to harm US personnel.

However, in the two dozen cases, the CIA did not rule out attacks by a foreign actor.

The experts meanwhile rejected other theories of AHI causes, including ionizing radiation, chemical and biological agents, infrasound, audible sound, ultrasound propagated over large distances, and bulk heating from electromagnetic energy.

All were "implausible" causes of the AHI symptoms, they said.