Diplomats in Guangzhou have been experiencing strange symptoms.
Diplomats in Guangzhou have been experiencing strange symptoms. chensiyuan/CC BY-SA 4.0

An unsolved health mystery has haunted American diplomats for more than a year and half now. Starting in 2016, U.S. representatives in Cuba experienced hearing loss and and other cognitive problems usually associated with concussions and other trauma to the head.

Scientists still haven’t figured out why or how the symptoms started and what caused them. But the problem is spreading. Now, reports the New York Times, American employees of the consulate in Guangzhou, in southern China, are reporting the same symptoms.

In China, one diplomat who experienced the symptoms left in April; this week, another American and his family left to return to the United States for treatment and testing. The diplomats who reported problems with hearing loss, balance, vision, sleep, and headaches in Cuba were living in hotels and other dense dwellings—places where a listening device or other unknown technology could have easily been planted nearby. The Americans in China were living in similar situations—high-rise apartment buildings occupied by other foreign workers and wealthy locals.

Over the past several months, experts have floated many explanations for the symptoms the diplomats experienced. One leading theory has been that an eavesdropping device was to blame, but no one has been able to come up with a definitive answer. The people suffering from these symptoms have been treated by brain injury specialists at the University of Pennsylvania, who reported in the medical journal JAMA that they found cognitive, balance, and oculomotor abnormalities in most of the group from Cuba.

As a result of these strange occurrences, the U.S. and Canada have both pulled diplomats out of Cuba. But now it seems like this attack (or hysteria), whatever is causing it, may be much larger a problem than it originally seemed.