Global Affairs says it still has no idea what has caused headaches, dizziness for diplomats and families.

Eight Canadians posted to Cuba have experienced mysterious symptoms such as headaches, dizziness and nose bleeds in recent months, but Global Affairs officials say they are still at a loss to explain what is causing them.

The most recent incident affecting Canadian diplomats and members of their families took place in December. The person affected said they suddenly felt a wave of pressure. Symptoms reported by others have included headaches, dizziness, nose bleeds, loss of balance and sleeplessness. The symptoms reported by the Canadians have not been as severe as those reported by some Americans.

While one person affected continues to experience headaches, Canadian officials said Wednesday there is no indication following medical testing that anyone has experienced permanent damage.

Officials told reporters during a background briefing in Ottawa Wednesday they are in uncharted territory and have never seen anything like it anywhere else in the world. At this point, they said, they haven’t ruled out anything, including foul play.

The mysterious ailments, which have triggered speculation worthy of a spy thriller, appear to only be hitting Canadian and American diplomats posted to Havana, Cuba.

U.S. media reported last year that U.S. authorities were investigating the possibility the diplomats and their families had been targeted by some kind of “sonic attack.” However, The Associated Press on Monday cited a new FBI report that said the U.S. has found no evidence sonic waves were used.

U.S. officials told a congressional hearing Tuesday they are still working on several theories — including the possibility a virus was used.

Canadian officials said there have been no reports of similar symptoms among staff of other embassies or among Cubans. Nor have there been any reports of unusual symptoms among the thousands of Canadian tourists who visit Cuba every year.

The United States reduced the number of people posted to its embassy in response to the problems reported by 24 U.S. personnel and members of their families.

However, Canadian officials said they have no plans to reduce staff at its embassy. While a small number of diplomats and their families have opted to return to Canada, others have been sent to replace them after being fully briefed.

At the same time, the government has increased security measures around both the embassy and the residences of staff members.

Among the aspects officials have been studying are infrasound, ultrasound and environmental factors. While doctors have determined that some of the symptoms could be produced by auditory trauma, they said there is no known sonic weapon.

The U.S. government warns travellers to Cuba that embassy employees have been targeted by attacks and U.S citizens could be as well — particularly around the Hotel Nacional and Hotel Capri in Havana. The Canadian government is not planning to add a similar warning to its travel advisory.

While the officials did not say it, adding a warning to a travel advisory can have significant repercussions for businesses like insurance companies and airlines.

The first reported symptoms occurred in March 2017 but there was a cluster around May 2017 after the Canadian Embassy was approached by the American Embassy and it began to ask staff if they had experienced anything.

Overall, 27 staff members or their family members went through a medical examination and eight received further followup medical treatment.

The government is also doing baseline testing of those being posted to the embassy in Cuba, including those sent there temporarily, to allow them to determine if there are any future changes.

While a number of American staff said they heard a high-pitched sound before they began experiencing symptoms, only one Canadian reported that kind of sound.

The Canadians reported feeling the symptoms at their homes, rather than at the embassy.

Officials said Cuban officials appear to be as puzzled by the strange symptoms as the Canadians and Americans.

By Elizabeth Thompson · CBC News

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