The matter first came to light in 2017, when Washington recalled the majority of its personnel from its embassy in Havana, Cuba, and at least two more diplomats from its consulate in the Chinese city of Guangzhou. The evacuees reported experiencing “unusual acute auditory or sensory phenomena” and hearing “unusual sounds or piercing noises”. Subsequent tests showed that the diplomats suffered from sudden and unexplained loss of hearing, and possibly from various forms of brain injury.

Now a new report by The New Yorker’s Adam Entous claims that “about two dozen” personnel at the US embassy in Vienna have shown Havana syndrome symptoms “since Joe Biden took office” in January of this year. If accurate, this number of incidents would mean that the Austrian capital is now the largest Havana syndrome location in the world after Cuba. In his report, Entous cited a spokesman for the US Department of State, who said that department was “vigorously investigating” reports of “possible unexplained health incidents” among US diplomats and other embassy personnel in Vienna. The expression “unexplained health incidents” is the official term that the US government uses to refer to what is informally known as the Havana syndrome.

Meanwhile, the Reuters news agency reported a statement issued on Saturday by the Austrian Federal Ministry for European and International Affairs. It said the ministry was “working with the US authorities on jointly getting to the bottom of this”, adding that the Austrian government took “these reports very seriously”, as they potentially affected “the safety of the diplomats sent to Austria and their families”, which was a “top priority” for the Austrian government.