A USA government employee in China reported abnormal sensations of sound and pressure ahead of being diagnosed with a mild brain injury, in a case reminiscent of diplomats who fell ill in Cuba a year ago.
The US Embassy in Beijing learned on May 18 that the clinical findings of the evaluation matched that of a "mild traumatic brain injury", an embassy spokeswoman told CNN. A spokeswoman for the U.S. Embassy in Beijing said that from late 2017 to April 2018, a government employee assigned to Guangzhou reported an unusual physical symptoms.
The embassy advised Americans experiencing "unusual acute auditory or sensory phenomena accompanied by unusual sounds or piercing noises" not to attempt to locate the source of the sound but to move away from the location, and seek medical help.
The U.S. previous year chose to withdraw a large number of embassy staff from the country after diplomats stationed there complained of symptoms like hearing loss, dizziness, tinnitus, visual difficulties, headaches, fatigue and other symptoms.
The health alert issued Wednesday warned US citizens to be vigilant.
The State Department urged citizens to seek medical counsel if they experience similar symptoms.
The State Department's health advisory noted the cause of the symptoms is unknown.More news: Nigeria condemns killing of 58 Palestinians
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The worker was sent to the United States for further evaluation.
The Chinese foreign ministry could not be immediately reached for comment. The Chinese government has assured the USA that it is investigating the matter and taking appropriate measures, according to a State Department spokesperson.
Investigators suspected use of a "sonic weapon", but there has been no proof that was the cause. Media reports have suggested that the Federal Bureau of Investigation has not been able to verify any evidence to support the sonic weapon theory.
Staff there reported symptoms including hearing loss, dizziness, fatigue and cognitive issues, though Cuban officials dismissed the idea of acoustic strikes as "science fiction" and accused Washington of slander.
The US government has held Cuba responsible, arguing that Raul Castro's authoritarian state must have either carried out the assaults or at least known who was behind them.
The State Department also ordered non-essential embassy personnel and the families of all staff to leave Havana.
Unlike their American counterparts, however, no Canadian envoy reported hearing any suspicious sound prior to falling ill.