The 2020 National Academies study found that it was unlikely that "acute high-level exposure to OPs and/or pyrethroids contributed" to the illnesses, due to a lack of evidence of exposures to those pesticides or clinical histories consistent with such exposure, but the study committee "could not rule out the possibility, although slight, that exposure to insecticides, particularly OPs, increased susceptibility to the triggering factor(s) that caused the Embassy personnel cases." The National Academies study committee also found it "highly unlikely" that an infectious disease (such as Zika virus, which was an epidemic in Cuba in 2016–17) caused the illnesses.
In March 2018, MRI scans and other tests taken by a chief neurologist in Pittsburgh on an unspecified number of Canadian diplomats showed evidence of brain damage that mirrored the injuries some of their American counterparts had faced. In early 2018, Global Affairs Canada ended family postings to Cuba and withdrew all staff with families. Several of the Canadians who were affected in 2017 were reported to still be unable to resume their work due to the severity of their ailments. The lack of knowledge of the cause of Havana syndrome, as of February 2019 , had made it challenging for the Royal Canadian Mounted Police to investigate.
In August 2017, reports began surfacing that American and Canadian diplomatic personnel in Cuba had experienced unusual, unexplained health problems dating to late 2016. As of June 2018, the number of American citizens experiencing symptoms was 26.
In August 2017, the United States expelled two Cuban diplomats in retaliation for perceived Cuban responsibility. The next month, the U.S. State Department stated that it was removing non-essential staff from the U.S. embassy and warned U.S. citizens not to travel to Cuba. In October 2017, President Donald Trump said he believed that Cuba was responsible for the occurrences, calling them a "very unusual attack".
In early 2018, reports similar to those made by diplomats in Cuba began to be made by U.S. diplomats in China. The first incident reported by an American diplomat in China was in April 2018 at the Guangzhou consulate, the largest U.S. consulate in China. The employee reported that he had been experiencing symptoms since late 2017. Several individuals were taken to the United States for medical examination. Another incident had previously been reported by a USAID employee at the U.S. embassy in Tashkent, Uzbekistan, in September 2017; the employee's report was discounted by the U.S. State Department.
A U.S. Office of Special Counsel investigation resulted in an April 2020 determination that there was "a substantial likelihood of wrongdoing" by State Department leadership. Mark Lenzi, who was a State Department diplomatic security officer stationed in Guangzhou, accused the department of a "deliberate, high-level cover-up" and of failing to protect their employees. Marc Polymeropoulos, a 26-year CIA veteran, who retired in 2019, similarly felt betrayed by CIA leadership, accusing the agency of failing to respond appropriately to a vertigo-inducing attack in Moscow in December 2017 (which Polymeropoulos called "the most terrifying experience of my life" and more frightening than experiences in Iraq and Afghanistan). Polymeropoulos fought with the CIA for years to obtain specialized medical treatment, after the agency cast doubt on the similarities between the symptoms he experienced and those suffered by the diplomats in Havana. Polymeropoulos was ultimately diagnosed at the U.S. government's Walter Reed Medical Center with traumatic brain injury; attorney Mark Zaid, who represented almost a dozen clients who had become ill from similar attacks, said that Polymeropoulos was the only one of his clients who had received treatment at Walter Reed, with others obtaining treatment only from personal doctors or academic medical centers.
In response to a December 2017 State Department request, the U.S. Centers for Disease Control and Prevention conducted a "Cuba Unexplained Events Investigation." The two-year investigation of the medical records of 95 U.S. diplomats and family members in Havana who reported symptoms resulted in a final report, marked for official use only, dated December 2019.
In 2018, U.S. diplomats in China reported problems similar to those reported in Cuba, as did undercover CIA agents working in other countries with partner agencies on missions aimed at countering Russian covert operations.
In January 2018, at the direction of Secretary of State Rex Tillerson, the State Department convened an accountability review board, which is "an internal State Department mechanism to review security incidents involving diplomatic personnel." Retired United States Ambassador to Libya Peter Bodde was chosen to lead the board.
In January 2018, the Associated Press reported that a non-public FBI report found no evidence of an intentional sonic attack. A November 2018 report in the New Yorker found that the FBI's investigation into the incidents was stymied by conflict with the CIA and the State Department; the CIA was reluctant to reveal, even to other U.S. government agencies, the identities of affected officers because of concern about possible leaks. Federal rules on the privacy of employee medical records also hindered the investigation.
At the request of the U.S. government, University of Pennsylvania researchers examined 21 affected diplomats, and the preliminary results were published in the Journal of the American Medical Association (JAMA) in March 2018. The report "found no evidence of white matter tract abnormalities" in affected diplomats beyond what might be seen in a control group of the same age and described "a new syndrome in the diplomats that resembles persistent concussion." While some of those affected recovered swiftly, others had symptoms for months. The study concluded that "the diplomats appear to have sustained injury to widespread brain networks."
In March 2018, Kevin Fu and a team of computer scientists at the University of Michigan reported in a study that ultrasound—specifically, intermodulation distortion from multiple inaudible ultrasonic signals—from malfunctioning or improperly placed Cuban surveillance equipment could have been the origin of the reported sounds.
On March 2, 2018, the U.S. State Department announced it would continue to staff its embassy in Havana at the minimum level required to perform "core diplomatic and consular functions" due to concerns about health attacks on staff. The embassy had been operating under "ordered departure status" since September, but the status was set to expire. This announcement served to extend the staff reductions indefinitely.
Answering questions from the House Foreign Affairs Committee on May 23, 2018, Secretary of State Mike Pompeo testified that U.S. diplomatic staff in Guangzhou had reported symptoms "very similar" to, and "entirely consistent" with, those reported from Cuba. On June 6, 2018, The New York Times reported that at least two additional U.S. diplomats stationed at the Guangzhou consulate had been evacuated from China and reported that "it remains unclear whether the illnesses are the result of attacks at all. Other theories have included toxins, listening devices that accidentally emitted harmful sounds, or even mass hysteria." In June 2018, the State Department announced that a task force had been assembled to investigate the reports and expanded their health warning to all of mainland China amid reports some US diplomats outside of Guangzhou had experienced the same symptoms resembling a brain injury. The warning told anyone who experienced "unusual acute auditory or sensory phenomena accompanied by unusual sounds or piercing noises" to "not attempt to locate their source."
In 2019, the Canadian government announced that it was reducing its embassy staff in Havana after a 14th Canadian diplomat reported symptoms of Havana syndrome in late December 2018. In February 2019, several Canadian diplomats sued the Canadian government, arguing that it failed to protect them or promptly address serious health concerns. The government has sought to dismiss the suit, arguing in November 2019 that it was not negligent and did not breach its duties to its employees. In court filings, the government acknowledged that several of the 14 plaintiffs in the suit suffered concussion-like symptoms but said that no definitive cause or medical diagnosis had been ascertained. In a November 2019 statement, Global Affairs Canada said, "We continue to investigate the potential causes of the unusual health symptoms."
A 2021 article by Julia Ioffe in GQ magazine stated that the "most compelling evidence" of Russian involvement derives from mobile phone tracking: "Using this sort of data, CIA investigators were able to deduce the whereabouts of Russian agents, and place them in close physical proximity to the CIA officers at the time they had been attacked when they were in Poland, Georgia, Australia, and Taiwan. In each case, individuals believed to be FSB agents were within range of the CIA officers who had been hit in 2019. In two of the incidents, location data apparently showed FSB agents in the same hotel at the same time their targets experienced the onset of symptoms."
A study of affected diplomats in Cuba published in the medical journal JAMA in 2019 found evidence that the diplomats experienced some form of brain injury but did not determine the trauma's cause or specific character. While there is no expert consensus on the syndrome's cause, a co-author of the JAMA study considered microwave weapons "a main suspect". An expert committee of the National Academies of Sciences, Engineering, and Medicine concluded in December 2020 that microwave energy (specifically, directed pulsed RF energy ) "appears to be the most plausible mechanism in explaining these cases among those that the committee considered" but that "each possible cause remains speculative." In 2021, investigators considered new evidence, including blood markers from patients that had recently been collected and analyzed systematically.
In 2019, a White House official reported experiencing debilitating symptoms while walking her dog in a Virginia suburb of Washington; the incident was publicly reported in 2020. In November 2020, a similar incident was reported on The Ellipse, a lawn adjacent to the south side of the White House. Both incidents were similar to those that were reported to have struck dozens of U.S. personnel overseas, including CIA and State Department personnel. Federal agencies investigated the incident at The Ellipse, and Defense Department officials briefed members of the Senate Armed Services Committee and House Armed Services Committee in April 2021. Investigators told members of Congress that they had not been able to determine the cause of the events or who was responsible, although officials indicated that it was possible that Russia or China were responsible.
U.S. personnel in Cuba made sound recordings that they released to the Associated Press. In January 2019, biologists Alexander L. Stubbs of the University of California, Berkeley and Fernando Montealegre-Z of the University of Lincoln analyzed the recordings and concluded that the sound was caused by the calling song of the Indies short-tailed cricket (Anurogryllus celerinictus) rather than a technological device. Stubbs and Montealegre-Z matched the song's "pulse repetition rate, power spectrum, pulse rate stability, and oscillations per pulse" to the recording. Stubbs and Montealegre wrote, "the causes of the health problems reported by embassy personnel are beyond the scope of this paper" and called for "more rigorous research into the source of these ailments, including the potential psychogenic effects, as well as possible physiological explanations unrelated to sonic attacks." This conclusion was comparable to a 2017 hypothesis from Cuban scientists that the sound on the same recording is from Jamaican field crickets.
A 2019 study commissioned by Global Affairs Canada of 23 exposed Canadian diplomats, completed in May 2019, found "clinical, imaging, and biochemical evidence consistent with the hypothesis" of overexposure to cholinesterase inhibitors (a class of neurotoxic pesticide) such as pyrethroids and organophosphates (OPs) as a cause of brain injury; the embassies and other places in Cuba had been sprayed frequently as an anti-Zika virus mosquito control measure. The study concluded that other possible causes could not be ruled out.
Three White House staffers reported symptoms at the InterContinental London Park Lane in late May 2019.
JASON, a group of physicists and scientists who advise the U.S. government, analyzed audio recordings from eight of the original 21 incidents of Havana Syndrome and two cellphone videos taken by one patient from Cuba. It concluded that the sounds in the eight recordings were "most likely" caused by insects and that it was "highly unlikely" that microwaves or ultrasound beams were involved, because "No plausible single source of energy (neither radio/microwaves nor sonic) can produce both the recorded audio/video signals and the reported medical effects." The group determined with "high confidence" that the two videos were sounds from the Indies short-tailed cricket, and also noted a "low confidence" hypothesis that the noises may have been from a concrete vibrating machine with worn bearings. The report's findings were first reported by Reuters in July 2019. Parts of JASON's report were declassified in September 2021. While biomedical engineer Kenneth Foster (an opponent of the microwave theory) cited the findings as evidence against the theory, biomedical engineer James Lin (a proponent of the microwave theory) said that the recordings the JASON report analyzed could not represent actual cases of Havana syndrome, since typical sound recorders cannot record microwaves.
Subsequent findings by the University of Pennsylvania team, published in July 2019, found that, compared to a healthy control group, the diplomats who had reported injury had experienced brain trauma. Advanced MRI scans (specifically res-fMRI, multimodal MRI, and diffusion MRI) revealed "differences in whole brain white matter volume, regional gray and white matter volume, cerebellar microstructural integrity, and functional connectivity in the auditory and visuospatial subnetworks" but found no differences in executive functions. The study concluded that the U.S. government personnel had been physically injured in a way consistent with the symptoms they described but expressed no conclusion on the cause or source of the injury. The New York Times reported: "Outside experts were divided on the study's conclusions. Some saw important new evidence; others say it is merely a first step toward an explanation, and difficult to interpret given the small number of patients."
In October 2020, the New York Times reported that U.S. diplomats and intelligence officers, including senior leaders, had clashed with Trump administration appointees, including CIA director Gina Haspel and State Department leaders, over the nature and causes of the suspected attacks. A Times investigation found that the State Department had "produced inconsistent assessments of patients and events, ignored outside medical diagnoses and withheld basic information from Congress." Despite the general view within the U.S. government that Russia was responsible, two U.S. officials told the Times that Haspel was not convinced of Russia's responsibility, or even whether an attack occurred.
In December 2020, a study by an expert committee of the U.S. National Academies of Sciences, Engineering, and Medicine, commissioned by the State Department, released its report, concluding, "Overall, directed pulsed RF energy ... appears to be the most plausible mechanism in explaining these cases among those that the committee considered" but that "each possible cause remains speculative" and that "the report should not be viewed as conclusive". Chaired by David Relman, the committee included Linda Birnbaum, Ronald Brookmeyer, Caroline Buckee, Joseph Fins, David A. Whelan, and others. The panel stated that a lack of information (such as medical testing data about affected persons) limited what it could conclude about explanations of the phenomenon.
In December 2020, the CIA established a task force to investigate the attacks. The agency set up the task force after continued reports of debilitating attacks against CIA officers in various places around the world. The CIA expanded its investigation under Director William Joseph Burns, who took office in 2021; Burns appointed a senior CIA officer who had previously led the manhunt for Osama bin Laden to lead the agency's investigation. In March 2021, the State Department appointed Ambassador Pamela Spratlen, a career foreign service officer, to oversee the department's response to the attacks. Six months later, Spratlen was removed because she "reached the threshold of hours of labor", but her resignation had been demanded by people angered by her handling of a conference call in which psychogenic causes were discussed.
Near the end of the Trump administration, the Defense Department established a task force to investigate reports of attacks on DoD personnel abroad. The DoD established the task force partly due to frustration over what DoD officials considered to be a sluggish and lackluster response by the CIA and Department of State. Christopher C. Miller, who was acting defense secretary at the time, said in 2021 that, "I knew CIA and Department of State were not taking this shit seriously and we wanted to shame them into it by establishing our task force." Miller said that he began to consider the reports of mysterious symptoms to be a high priority in December 2020, after he conducted an interview with a person with major combat experience who detailed symptoms.
A 2018 State Department report was declassified, and posted on the George Washington University's National Security Archive, after Freedom of Information Act litigation brought by the James Madison Project. The documents indicate that the initial State Department handling of the attacks was botched. Peter Kornbluh of the National Security Archive noted that the 2018 report concluded that the department's "initial investigation assessment of what was going on" was marred by chaos, disorganization, and excessive secrecy. In 2021, sources familiar with the various ongoing investigations told CNN that a primary obstacle to progress by the U.S. government in investigating the syndrome was a lack of interagency coordination between the CIA, FBI, Centers for Disease Control and Prevention, and State Department, which conducted separate and "largely siloed" investigations. The limited coordination among the varying agencies was based in part on "the highly classified nature of some details and the privacy restrictions of health records, and that has hampered progress."
In 2021, dozens of U.S. personnel stationed in Vienna, including diplomats, intelligence officials, and some children of U.S. employees, suffered Havana syndrome-like symptoms. The State Department confirmed in July 2021 that it was investigating the reports. The Austrian foreign ministry stated it was collaborating with American investigators. Aside from Havana, Vienna has reported the most incidents. While no suspects were named for the Vienna cases, it has been noted that Vienna was hosting indirect talks between the United States and Iran on reviving the 2015 Iran deal. In September 2021, the CIA station chief in Vienna (the top U.S. intelligence officer in the country) was recalled over concerns over his management; he had been criticized for not taking quicker action in response to the Havana syndrome cases at his post.
In 2021, the CIA evacuated an intelligence officer serving in Serbia suspected of being a victim of the neurological attack.
The Cuban government offered to cooperate with the U.S. in an investigation of the incidents. It employed about 2,000 scientists and law enforcement officers who interviewed 300 neighbors of diplomats, examined two hotels, and medically examined non-diplomats who could have been exposed. NBC reported that Cuban officials stated that they analyzed air and soil samples and considered a range of toxic chemicals. They also examined the possibility that electromagnetic waves were to blame, and even looked into whether insects could be the culprit, but found nothing they could link to the claimed medical symptoms. The FBI and Cuban authorities met to discuss the situation; the Cubans stated that the U.S. neither agreed to share the diplomats' medical records with Cuban authorities nor allowed Cuban investigators access to U.S. diplomats' homes to conduct tests. In 2021, a panel of 16 scientists affiliated with the Cuban Academy of Sciences and convened by the Cuban government reported that "the narrative of the 'mysterious syndrome' is not scientifically acceptable in any of its components." The panel addressed the microwave hypothesis directly, writing that "[n]o known form of energy can selectively cause brain damage (with laser-like spatial accuracy) under the conditions described for the alleged incidents in Havana."
The Senate Intelligence Committee leadership (chairman Mark Warner and vice chairman Marco Rubio) said in 2021 that it was working with Burns and the CIA on connection with the investigation, saying, "We have already held fact finding hearings on these debilitating attacks, many of which result in medically confirmed cases of Traumatic Brain Injury, and will do more." In May 2021, Politico reported that intelligence officials had recently told Congress that the investigation had expanded to include all 18 federal intelligence agencies and had focused "on the potential involvement of GRU, the Russian spy agency".
The U.S. government has not released the number of affected persons, but media reporting indicated a total of 130 possible cases by the end of May 2021, rising to more than 200 possible cases by mid-September 2021. The cases variously affected CIA, U.S. military, and State Department personnel and their family members. Some reports, after investigation, were determined to be possibly related to Havana syndrome, while others were determined to be unrelated; BBC News reported in 2021 that "One former official reckons around half the cases reported by US officials are possibly linked to attacks by an adversary."
In January 2021, both BuzzFeed News and George Washington University's National Security Archive obtained the report, pursuant to Freedom of Information Act requests. (Some material in the released report was redacted for medical privacy reasons.) The CDC developed a "case definition" of the Havana syndrome, consisting of a biphasic (two-stage) syndrome, with the first phase of symptoms (sometimes closely after an auditory or sensory event) followed by "cognitive deficits or vestibular disturbances" some time later. The report concluded, "Of the 95 persons whose medical records CDC evaluated, 15 had illnesses that met the criteria for a presumptive case definition. CDC classified 31 others as possible cases and the remaining 49 as not likely to be a case." Two years later, six of the subjects in the CDC investigation were still being rehabilitated for their injuries, and four were still unable to return to work. The CDC decided not to conduct a retrospective case–control study because of the length of time between the event and the onset of symptoms, which could lead to recall and selection biases that "could generate misleading or obscured findings."
The U.S. State Department said in February 2021 that its ongoing investigation was "a high priority" for the department. Citing unnamed intelligence and government officials, The New York Times reported in July 2021 that the National Security Council, Central Intelligence Agency, and Director of National Intelligence established two outside panels, one to investigate potential causes and the other to develop defensive countermeasures for personnel protection; cleared external scientists will be permitted to view relevant classified intelligence in their investigations.
In May 2021, Politico reported that three current and former U.S. officials "with direct knowledge of the discussions" said that the U.S. government suspected that Russia's military intelligence agency, GRU, was behind alleged attacks, although the U.S. Intelligence Community have not "reached a consensus or made a formal determination." In May 2021, The New Yorker reported that the U.S. government's "working hypothesis" was that GRU agents "have been aiming microwave-radiation devices at U.S. officials to collect intelligence from their computers and cell phones, and that these devices can cause serious harm to the people they target." The U.S. government has not publicly accused Russia of the attacks; U.S. intelligence officials privately call the events "attacks" but publicly call them "anomalous health incidents." According to two officials interviewed by Politico, "While investigators have not determined definitively that these incidents are caused by a specific weapon, some believe any such device would be primarily transported by vehicle", and "Some could be small enough to fit into a large backpack, and an individual can be targeted from 500 to 1,000 yards away." James Lin of the University of Illinois, an expert on the biological effects of microwave energy, agreed that an Havana syndrome attack could be caused by a small apparatus that could fit in a van or SUV.
In August 2021, it was reported that two American diplomats were evacuated from the U.S. Embassy in Hanoi, Vietnam, after incidents of Havana syndrome were reported. These reported cases also delayed Vice President Kamala Harris's visit to Vietnam.
In the months preceding August 2021, cases of Havana syndrome were reported at the U.S. embassy in Berlin, Germany, including from two U.S. officials who sought medical treatment. Several new cases were reported at the embassy in October 2021.
In September 2021, CIA Deputy Director David S. Cohen said that the investigation had "gotten closer" to making a determination, "but not close enough to make the analytic judgment that people are waiting for."
In September 2021, a CIA officer traveling with chief William Joseph Burns reported symptoms consistent with those of Havana syndrome on a diplomatic visit to India.
In October 2021 it was reported that U.S. embassy personnel and their families in Bogota, Colombia, had come down with symptoms linked with the syndrome.
In response to Havana syndrome, U.S. Senator Susan Collins introduced a bill (S. 1828), co-sponsored by a bipartisan group of nine other senators, that would close a loophole in the Federal Employees' Compensation Act that would normally not cover damage to organs such as the brain and heart. The Helping American Victims Afflicted by Neurological Attacks (HAVANA) Act authorized the CIA Director and the Secretary of State to provide financial support for personnel suffering brain injuries. The bill unanimously passed the U.S. House of Representatives on a 427–0 vote, passed the U.S. Senate by unanimous consent, and was signed into law by President Joe Biden on October 8, 2021, becoming Public Law No. 117-46.
Havana syndrome is a set of medical signs and symptoms that include ringing in the ears, fatigue and dizziness. United States and Canadian embassy staff first reported the syndrome in Havana, Cuba, in late 2016, and subsequently in other countries.
Beginning in late 2017, attacks targeting U.S. intelligence personnel were reported in an expanding set of locations around the world, including Moscow, Russia; Poland; Tbilisi, Georgia; Taiwan; and Australia. Other reports came from Colombia, Kyrgyzstan, Uzbekistan, and Austria, among other countries.