Updated Apr 1, 2024 - Politics & Policy

What to know about Havana Syndrome after investigation links illness to Russia

 US Embassy on the day of its reopening for visa and consular services in Havana

The U.S. Embassy in Havana, Cuba on Jan. 4. Photo: Yander Zamora/Anadolu Agency via Getty Images

New evidence suggests that Russia may be behind the mysterious neurological illness that has affected U.S. diplomats and government workers around the world.

Why it matters: A new investigation linked a Russian military assassination unit to cases of "Havana Syndrome," contradicting the U.S' previous assessment that it was "very unlikely" a foreign adversary was to blame.

The latest: The joint investigation published Sunday by The Insider, Der Spiegel and CBS's 60 Minutes found that Russia's GRU Unit 29155 may be behind the attacks.

  • Kremlin spokesperson Dmitry Peskov on Monday denied Russia's involvement in Havana Syndrome cases, telling reporters "all this is nothing more than a baseless accusation, an unfounded accusation by the media," Russian state news agency TASS reported.
  • "We're going to continue to do a comprehensive examination of the effects here that we're seeing and the potential causes," White House press secretary Karine Jean-Pierre said at a press briefing Monday.
  • She added that the U.S. intelligence community had not reached the same conclusion as the investigation.

What is Havana Syndrome?

The mysterious illness is also sometimes referred to as "Anomalous Health Incidents" (AHI) by U.S. officials.

  • Symptoms include extreme headaches, dizziness, nausea and ear pain.
  • Two major National Institutes of Health studies published last month found no evidence of brain injury among patients believed to have Havana Syndrome.
  • David Relman, a Stanford University scientist who's led previous research into the condition, took issue with the findings in an accompanying editorial, noting they contradict some earlier studies.

Where has Havana Syndrome been reported?

The ailment was dubbed "Havana syndrome" after reports of American officials falling ill were first documented at the U.S. Embassy in Cuba in 2016.

  • Yet the new joint investigation suggests the cases may have surfaced two years earlier, in Frankfurt, Germany.
  • Overall, U.S. officials estimate that some 1,500 cases of Havana Syndrome among U.S. government personnel have been reported across 96 countries, per CNN.
  • These also include suspected cases in China, India, Austria, and Vietnam.
  • Pentagon deputy press secretary Sabrina Singh told reporters Monday that a senior Pentagon official who attended last year's NATO summit in Lithuania "experienced symptoms similar to those reported in anomalous health incidents."

What causes it?

There are a few theories.

  • A 2020 National Academies of Sciences, Engineering, and Medicine report proposed that the neurological symptoms could be the result of a radio frequency energy of radiation that includes microwaves.
  • Some lawmakers have also suggested the cases are a result of directed energy attacks.

State of play: Yet U.S. intelligence agencies said last year it was "very unlikely" a foreign adversary was responsible for the cases of Havana Syndrome.

  • That assessment echoed a 2022 preliminary CIA report that also found a foreign power was likely not behind the cases.
  • A CIA official told Axios in 2022 that many of the Havana Syndrome cases could be explained by other undiagnosed medical conditions or environmental or technical factors.
  • The Office of the Director of National Intelligence reiterated in its 2024 Annual Threat Assessment last month that AHI cases "did not involve a foreign adversary."

State Department spokesman Matthew Miller said at a press briefing Monday the department still has confidence in these previous assessments.

  • "It's something the intelligence community has investigated extensively and continues to look at. We will look at new information as it comes in and make assessments," he added.

Yes, but: The new investigation published Sunday pointed to the potential use of directed energy weapons by Russia's GRU Unit 29155.

  • According to The Insider, senior members of the unit received awards and promotions for their work on the development of "non-lethal acoustic weapons."

What has been done to help those affected?

American diplomats and other government staffers suffering with symptoms of Havana Syndrome wrote to the State Department in May 2021 to raise concerns that some injured workers were being denied proper care.

  • In October 2021, President Biden signed a bill to authorize additional support for patients experiencing Havana Syndrome.

Editor's note: This story was updated with new comments from White House, Pentagon and State Department spokespeople.

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