When dozens of US and Canadian diplomats and their families in Cuba began showing symptoms of a mysterious illness, security officials were quick to blame an equally mysterious "sound weapon" right out of spy fiction.  

It started in 2016 when patients complained of a range of unusual symptoms including hearing and vision complications, dizziness, fatigue, and headaches.  The US and Canada never explained what the "acoustic weapon" could have been.  And after Cuba repeatedly denied allegations of a secret weapon, the US and Canadian security officials never came up with another theory of who would be using it or why.

But Canadian scientists now say the patients were sickened by Mozzie spray - gas used to cut down the mosquito population on the tropical island in the midst of a Zika virus outbreak.  The new study from the Brain Repair Centre and the Nova Scotia Health Authority gave no credence to the spies' acoustic weapon theory.  

"There are very specific types of toxins that affect these kinds of nervous systems," said the study's lead author Dr. Alon Friedman to the CBC, "And these are insecticides, pesticides, organophosphates - specific neurotoxins." 

Cuban records indicate that diplomatic residences and offices were on the list of places to sprayed to abate the mosquito nuisance.