Some of those showing symptoms include minors.
Spouses, children, or even parents of Canadian diplomats now accompanying them in Havana will begin leaving the Cuban capital immediately.
As a favorite tourist destination for Canadians, Cuba annually attracts more than 1 million tourists, and Global Affairs Canada says there is no evidence of any related ailments among Canadian travellers.
Diaz-Canel would be the first president since Cuba's leftist 1959 revolution to be born after it. Castro, who formally took over the presidency 10 years ago from his brother, Fidel Castro, will remain head of the Communist Party, Cuba's sole political party.
Canadian medical specialists, working with American counterparts who have been studying USA diplomats who suffered similar health problems are now working on the theory that they have suffered a "new type of possible acquired brain injury". Washington recalled its staff in September and issued a travel warning against Cuba.
Global growth is expected be 3.9 percent in 2018 and 2019
The report kept the global growth rate projections at 3.9 percent for this year and the next that was made in January. Global growth is expected to tick up to a 3.9 percent rate in both 2018 and 2019, according to the report.
"Additional research is needed to better understand this".
Government officials declined to give further details of the new medical findings and referred reporters to the study itself, which was published in February by the Journal of the American Medical Association.
Global Affairs also emphasized that it had a "positive and constructive relationship with Cuba and has received close cooperation from the Cuban authorities since health concerns of Canadians serving in Cuba first surfaced in the spring of 2017".
The official, who spoke on background, bluntly admitted that nearly a year after the symptoms came to light, the US and Canadian governments appear no closer to discovering the cause, despite a sizeable investigation by police and diplomatic officials in both countries, aided by the Cubans.
Several theories about sonic attacks and psychological induced illnesses have been put forth but are now ruled out.
Numerous embassy staff were due to rotate out and be replaced this coming August, but now all those involved will be given time to re-evaluate their next moves, officials said.