The Canadian government said on Wednesday that it would withdraw up to half of its diplomatic staff in Havana, as it disclosed that another employee had fallen ill with the mysterious symptoms that have affected dozens of Americans and Canadians stationed in Cuba.

Since early 2017, American and Canadian government employees in Cuba have suffered strange symptoms such as dizziness, insomnia, hearing loss and nausea when using a computer. Canada’s government said that, in all, 14 Canadian employees, spouses and dependents have been affected.

Global Affairs Canada, the nation’s foreign ministry, said that after the last confirmed case of unusual symptoms, in November 2018, Canadian staff members in Havana undertook additional medical testing. Those tests confirmed “an additional employee has symptoms consistent with those of previously affected employees,” the ministry’s statement said.

Though the Canadian government had started “revised security measures,” it said, “we have decided to reduce by up to half the number of Canadian staff posted to Havana.”