“We report the clinical, imaging and biochemical evidence consistent with the hypothesis of over-exposure to cholinesterase inhibitors as the cause of brain injury.”
Canadian Study (September 2019)
“It took us many months to get to this conclusion, and there is lots of research to be done still, but this is the beginning of an answer to what happened, we think. There is a lot we don’t know about how much we can expose people to these chemicals and what are toxic levels, or if the damage in the brain is reversible. But it’s not called a neurotoxin for nothing. The hint is in the name.”
Dr. Alon Friedman — Professor of neuroscience at Dalhousie University in Halifax, Nova Scotia
“Do the results known to me fully support that the signs / symptoms occurring in US embassy personnel were solely due to cholinergic neurotoxicity? No, not completely.”
James Giordano PhD — Departments of Neurology and Biochemistry Georgetown University — Email to Intel Today (September 20 2019)
September 25 2019 — According to a new study commissioned by the Canadian government, fumigation against mosquitoes may have caused Canadian diplomats — and family members — to fall ill. Neither the diplomats nor the federal government consider the just-released report from Dalhousie University’s Brain Repair Centre as a conclusive answer. I am sceptical. On one hand, the Dalhousie report confirms that Canadian diplomats suffered brain injuries while posted in Havana. But in many ways, it brings more questions than answers. Follow us on Twitter: @INTEL_TODAY
RELATED POST: Havana Syndrome — “Embassy Encephalopathy: Induced Hearing Loss, Cognitive Dysfunction and Neuropathological Changes – Possible Causes, Mechanisms, and Effects” by Dr. James Giordano (Georgetown University)
RELATED POST: Havana Syndrome — TIMELINE [UPDATE – October 2018]
UPDATE (October 2 2019) — Several persons have contacted me regarding this post and I can state that not a single one of them believes that overexposure to pesticides caused the diplomats’ illness.
People point out, as I did, that this theory fails to explain why the pesticide only hurts the North American diplomats and not the Cubans?
Some authors are already suggesting that the Cuban population may be immune due to genetics. I do not believe this hypothesis for a second.
Moreover, there is an additional point to be made, as two readers of this blog suggest.
Surely, one could argue that Cuban authorities have indeed detected a health problem but that they are covering up the news.
It is certainly plausible. All governments lie and I do not expect Cuba to be an exception.
However, there are also hundreds of thousands of tourists from all over the world and there is no record of any of them falling ill with Havana syndrome.
[Estimated number of tourists in Cuba: 4 million in 2016, 4.7 million in 2017, 4.75 million in 2018, and over 5 million in 2019.]
How do you explain that? Please, keep in mind that the researchers involved in this new study were able to test several of the diplomats before and after their visit to Cuba and they noticed changes in the brains of those who had just spent a few weeks in Havana.
According to Chinese official media, “the findings refute the claim of a deliberate attack against the diplomats.”
The statement is simply false. But it is not really surprising that Chinese officials — and others — are eager to accept that hypothesis as the truth of what happened to these diplomats in Havana.
END of UPDATE
The Canadian study was conducted by a team of researchers affiliated with the Brain Repair Centre at Dalhousie University and the Nova Scotia Health Authority.
The researchers have detected brain damages in an area that causes symptoms reported by the diplomats.
They concluded that cholinesterase — a key enzyme required for the proper functioning of the nervous system — was being blocked in that area.
During the 2016-2018 period (when diplomats became ill), normal fumigation in Cuba was stepped up due to the Zika epidemic in the Caribbean. Some pesticides work by inhibiting cholinesterase.
“While the source of exposure to toxins of the cholinesterase inhibitor family is not yet confirmed in our study, the use of insecticides readily and evidentially suggests itself.
Importantly, certain chemical classes of pesticides, such as organophosphates and carbamates, work against insects by inhibiting the action of cholinesterase, but can also be poisonous to humans.”
Mass-spectrometry tests have detected the presence of cholinesterase-inhibiting insecticides, including Temephos, an organophosphorus that is used in Cuba to fight mosquitoes. The tests also found 3-phenoxybenzoic acid, a common insecticidal metabolite.
The research — funded by Global Affairs Canada — has not yet been published as it is undergoing the peer review process.
Exploring all avenues
Intel Today has long argued that the mass hysteria theory made no sense whatsoever.
Those who argue in favor of this explanation are insulting both the victims and our intelligence.
Cindy Calkin — a psychiatrist and member of the multidisciplinary research team — categorically rejects the idea of mass hysteria.
“I have interviewed all but one or two of the victims and I haven’t found any evidence of psychiatric disorder.
This is a very strong group, very resilient and there is no evidence of mass hysteria.
Part of the diagnostic of mass hysteria is that there is no underlying other medical cause that can be found.
And we found underlying medical evidence.”
In an email to CBC/Radio-Canada, spokesperson John Babcock said that Global Affairs Canada hasn’t definitively determined a cause to the mysterious ailments at this point.
“While we are exploring all avenues, including the research at Dalhousie, no definitive cause of the health incidents has been identified to date,” he said.
Please, keep in mind that in contrast to previous reports on American diplomats, most Canadians did not describe an acute, directional, unusual sensory and/or auditory stimulus.
Still, it would be an extraordinary coincidence if US and Canadian diplomats began to experience similar symptoms at the same time and the same place but for different reasons.
Opinion from an expert
Dr James Giordano — Departments of Neurology and Biochemistry Georgetown University Medical Center Washington, DC, USA — has researched the possible cause of the Havana Syndrome.
In the video posted below, Dr. Giordano provides an in-depth overview of the possible vectors for the otopathologic (ear-damaging) effects these individuals experienced, as well as the potential mechanisms and causes for such effects. [This video is based on a conference held on September 7 2018.]
I asked Professor James Giordano his views regarding this new study. Here is his answer.
As you may recall, one of the possibilities we considered upon first reviewing this case was exposure to some neuro-pharmacologic / toxic agent.
At that time, the possibilities included cisplatin, certain diuretics, salicylates, and cholinergics/anticholinesterases.
Serial exposure to low/moderate doses of cholinergic pesticides could produce a cascade of neurological features that are similar to some of those observed in the affected individuals.
My understanding is that there are some differences between US and Canadian personnel in the pattern of signs/symptoms and possible exposures
An important consideration would be whether metabolites of such compounds were retrieved from body fluid/tissue samples, and what were the time-courses of both retrieval and predicted exposure(s).
Is it possible that some individuals were exposed to cholinesterase inhibitors? Yes. indeed
Could this have been accidental exposure. Yes, indeed. Could this have been intentional exposure? Yes, indeed.
Do the results known to me fully support that the signs/symptoms occurring in US embassy personnel were solely due to cholinergic neurotoxicity? No, not completely.
Reaction from the diplomats
For the 15 diplomats and their families, the study is a new source of frustration.
“The report does not make any clear findings regarding the cause of Havana syndrome, instead only raising the ‘hypothesis’ of overexposure to insecticides as a ‘plausible’ cause.”
“The Canadian diplomats feel profoundly betrayed by the Canadian government. Canadian diplomats and their families deserve better.
Not only did Canada put them in harm’s way, but it is now re-victimizing them by failing to properly investigate and identify the actual cause of their injuries, by failing to provide them and their families with proper medical treatment and by failing to accept responsibility for the diplomats and their families who have been so severely injured while serving their country.”
The theory has of course a major flaw… Why would only a limited number of Canadian and American diplomats be affected given that insecticides were deployed aggressively throughout Havana beginning in 2016 to fight the mosquito-born Zika virus?
Moreover, we have been told that most US diplomats affected by this mysterious illness were in fact intelligence officers. How could neurotoxins differentiate between real diplomats and spooks?
PS — Please, notice how many months it took for the researchers to identify this neurotoxin and contrast this investigation with the Skripals’ story where Novichok was identified in a matter of hours.
“Embassy Encephalopathy”: Induced Hearing Loss, Cognitive Dysfunction and Neuropathological Changes — Possible Causes, Mechanisms, and Effects
James Giordano PhD — Departments of Neurology and Biochemistry Georgetown University Medical Center Washington, DC, USA
A Look at Evolution as “Havana syndrome” Linked to Pesticides – The Great Courses Daily
Havana Syndrome — Pesticide may have caused diplomats’ illness. Really? [Comments from Dr James Giordano]
Havana Syndrome — Pesticide may have caused diplomats’ illness. Really? [UPDATE : Better than the Crickets’ Theory but still implausible]