The U.S. Embassy in China issued a health alert on Wednesday after a U.S. government employee experienced an "abnormal" sound and suffered a mild brain injury - in an incident reminiscent of a mysterious illness that hit diplomats in Cuba.
The cause of the injuries is now unknown, and no other employees have experienced similar symptoms at this time. "The Chinese government has assured us they are also investigating and taking appropriate measures", she said. The employee was brought to the United States for medical evaluation and on May 18 the Embassy learned that the clinical findings of the evaluation showed mild traumatic brain injury (MTBI). "Instead, move to a location where the sounds are not present", the recommendation said.
The US state department has urged its staff in China to alert them to any abnormal hearing or vision issues after one employee reported mystery symptoms.
The report comes as the U.S.is seeking to negotiate concessions from China to narrow its trade deficit.
USA diplomats there experienced possible "sonic attacks", and the US eventually reduced the number of American employees there.
The US official at the consulate in Guangzhou experienced a variety of "physical symptoms" between late 2017 and April this year.
Charles Rosenfarb, a doctor and director of the department's Bureau of Medical Services, said the symptoms were mixed, but consistent with brain trauma.
"The (State) Department is taking this incident very seriously and is working to determine the cause and impact of the incident", Lee said.
"We can not at this time connect it with what happened in Havana, but we are investigating all possibilities", a United States embassy official told Reuters.
In November 2016, U.S. diplomatic staff in Cuba said they began to experience symptoms and were subsequently treated for hearing loss, dizziness, balance problems and insomnia, all of which occurred after their exposure to alleged acoustic attacks.
China's Foreign Ministry are investigating the incident in Guangzhou but is yet to comment.
Cuban officials dismissed the idea of acoustic strikes as "science fiction" and accused Washington of slander.