Liputan6.com, Jakarta - Havana Syndrome, also known as Anomalous Health Incident (AHI), is a controversial medical condition first reported in late 2016 by United States and Canadian diplomatic personnel in Havana, Cuba.
The condition is characterized by a series of mysterious neurological symptoms affecting more than 1,500 U.S. officials, including diplomats, intelligence officers, and military personnel, and their family members, in locations around the world.
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These cases have sparked intensive investigations and a long debate within the U.S. government and scientific community regarding the exact cause and nature of the syndrome.
Most recently, in January 2026, a report emerged that shocked the public: the Pentagon had tested a device believed to be capable of replicating the effects experienced by Havana Syndrome victims.
Havana Syndrome and Its Symptoms
Havana Syndrome, or Anomalous Health Incident (AHI), is not an officially recognized condition by the medical community, but it has affected many individuals.
Since the first case in Cuba in 2016, more than 1,500 United States and Canadian officials, including diplomats, intelligence officers, and military personnel, have reported experiencing similar symptoms in various countries, from Europe, Asia, Australia, and even within the United States itself.
People with Havana Syndrome report a variety of symptoms, often with a sudden onset, associated with unusual sensations of sound or pressure.
Commonly cited acute symptoms include a localized loud sound such as screeching, chirping, or piercing, followed by a throbbing headache, vertigo, nausea, and a ringing or popping sensation in the ears.
These symptoms typically subside within 10 to 30 minutes of their onset.
Recent Developments About Havana Syndrome
The US intelligence community has conducted numerous in-depth investigations into Havana Syndrome, with conclusions evolving over time.
The initial US intelligence assessment, completed in 2023, concluded that it was “extremely unlikely” that a foreign adversary was responsible.
However, this assessment did not completely rule out foreign involvement in a small number of cases.
The most recent review, released in January 2025, reaffirmed that the majority of the intelligence community continues to consider foreign involvement extremely unlikely.
Of the seven intelligence agencies involved, five concluded that it was extremely unlikely that a foreign adversary was behind the incidents.
However, two intelligence agencies revised their position, stating that it was “nearly equally likely” that a foreign adversary had developed a device capable of harming United States officials and their families, as reported by CNN.
Even so, they did not directly link the device to the reported Anomalous Health Incidents (AHIs).
Overall, the US intelligence community has not found evidence tying a foreign adversary to any of the specific events reported as possible AHI.
Furthermore, two National Institutes of Health studies published in March 2025 in the Journal of the American Medical Association found no significant physical differences between affected individuals and control groups in brain structure or function, adding another layer of complexity to understanding this condition.
Pentagon Mysterious Device Linked to Havana Syndrome
In January 2026, reports of the US government's acquisition and testing of a device possibly linked to Havana Syndrome again sparked global attention.
The US government secretly acquired this device in late 2024, which officials believe may be linked to Havana Syndrome.
The device was secretly purchased in the final weeks of the Biden administration by the Homeland Security Investigations (HSI) division of the Department of Homeland Security, using Pentagon funds exceeding eight figures.
The Pentagon has been testing this device, which emits pulsed radiofrequency energy, for over a year.
Department investigators believe it may be capable of reproducing the effects described by Havana Syndrome victims.
The device is described as portable, backpack-sized, and containing components of Russian origin, although not entirely Russian-made.
Some agencies remain skeptical of the theory that anomalous health incidents (AHI) suffered by personnel are linked to Russian directed energy weapons.
Details about the acquisition of this US device were reported by independent journalist Sasha Ingber and CNN, and were later picked up by CBS News.
However, US officials have not confirmed the claims.
Various Causal Theories
The exact cause of Havana Syndrome remains a mystery and the subject of heated debate among scientists and the intelligence community.
One of the most widely discussed theories is exposure to directed pulsed radiofrequency energy, or microwaves.
A 2020 report from the National Academies of Sciences, Engineering, and Medicine (NASEM) stated that "directed pulsed radiofrequency energy appears to be the most plausible mechanism to explain these cases."
A panel of technical and medical experts convened by the US intelligence community in 2022 also supported this theory, finding that some cases of Havana Syndrome may be caused by directed electromagnetic energy.
On the other hand, some experts and early investigations, including by the FBI, raised the possibility that the symptoms had a psychological origin or were a mass psychogenic illness.
This theory posits that individual behavior can change within a group, influencing the spread of the disease.
However, the NASEM study rejected this possibility due to the lack of consistent evidence of exposure and the discrepancy between the reported symptoms and the effects of the chemicals.