Kamala Harris’ planned trip to Vietnam had to be delayed this week, after two possible cases of Havana syndrome were reported in the country’s capital.
Harris’ trip from Singapore to Hanoi was delayed by more than three hours on Tuesday (24 August) by an investigation into the cases.
Officials eventually deemed it safe for Harris to make her scheduled stop in Vietnam, part of her trip across Asia to reassure allies about American foreign policy amid the evacuation of Afghanistan.
Press secretary Jen Psaki said US officials “take any reported incident of Havana syndrome seriously,” at a White House press briefing and said the latest reported case did not involve anyone travelling with Harris.
But what exactly is Havana syndrome? And should you be worried?
Here is everything you need to know.
What is Havana syndrome?
Havana syndrome is a set of unusual, unexplained health problems and symptoms first reported by US and Canadian embassy staff in Cuba in late 2016.
Those affected typically report the sudden onset of strange grating noises that they perceived as coming from a specific direction, and ranged in length from 20 seconds to 30 minutes.
Some of them experienced it as a pressure or a vibration - or as a sensation comparable to driving a car with the window partly rolled down - but the incidents always happened while the diplomats were either at home or in hotel rooms.
Some U.S. embassy individuals have experienced lasting health effects, including one who is said to now need a hearing aid.
Affected individuals described symptoms such as hearing loss, memory loss, and nausea. A study published in The Journal of the American Medical Association (JAMA) found evidence that the diplomats experienced some form of brain injury.
Should I be worried?
In short: no.
At this point in time, the exact cause of Havana syndrome has not been expertly verified.
But it does not appear to be a transmissible virus, and leading theories suggest it may be the result of directed microwave radiation.
The JAMA study considered microwave weapons to be “a main suspect” for the phenomenon, and a US National Academies of Sciences, Engineering, and Medicine committee concluded that microwave energy “appears to be the most plausible mechanism in explaining these cases”.
Other proposed theories posit that ultrasound caused by malfunctioning Cuban surveillance equipment could be to blame, or that even the sounds of a “a rare jungle cricket” could be behind the symptoms.
Those affected tend to be people in diplomatic roles, working at embassies and other institutions with influence over international relations.
Roughly 130 total possible cases of attacks have been reported, with about 50 affecting CIA personnel, and the rest being primarily US military personnel, State Department personnel, and their family members.
Who is to blame?
The cause of Havana syndrome is widely agreed to be microwave radiation, but who could be behind any such attacks?
The US intelligence services have not reached a consensus on the cause of Havana syndrome, but unnamed intelligence sources and two presidential administrations have expressed suspicions that the Russian military could be responsible.
A 2021 article published in GQ magazine said the "most compelling evidence" of Russian involvement was acquired through mobile phone tracking.
This allowed “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.”
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