Fumigation against mosquitoes rather than “sonic attacks” may have caused some 40 US and Canadian diplomats and family members in Cuba to fall ill, according to a report commissioned by the Canadian Government.

The incidents took place from late 2016 into 2018, causing the US administration to charge that diplomats were attacked by some sort of secret weapon. Canada refrained from such charges.

In 2017, the US reduced its embassy staff to a minimum and Canada followed more recently, citing the incidents and the danger posed to staff from what has become known as ‘Havana syndrome’.

Now Canadian researchers have detected brain damage in six brain regions and changes in blood-brain barrier permeability in Canadian diplomats who had spent time in Havana.