ME is more likely to be an autoimmune syndrome, triggered by some infectious agent AND another triggering factor
the intial pathogen is controlled by immune system, or isn't causing too much harm, and so for many years nothing untoward occurs
however, another infection or severe stress on immune system occurs which then loses control of the initial pathogen.
note most ME cases start with a viral infection, but some also occur after or combined with injury, poisoning etc.
Chronic low level mercury poisoning could well exacerbate almost any automimmune effect as it's very subtle and very nasty, and we now know a hell of a lot more folk are sensitive to it than the dental associations have said, the shmucks.
That WOULD explain a lot of the issues with ME, especially if the autoimmune response is a "standardresponse type" the body has, because ME is so like the Flu/Lyme etc effects in general (but not 100% exact)
it's a common respons mechanism, thet gets stuck to "on" because the the body knows there's persistant infection, or something's "jammed" the system on.
Please remember, many infectious agents and parasites modulate the immune system, or cloak themselves to hide from it.
Just because you have an infectious agent does NOT mean you are going to have vast global death tolls with folk keeling over within days of infection, for Pete's sake, jeesh! For example, huge numbers of people have persistant herpes infections. So, if ME has a specific cause, it could be very common but dormant/little harm in most folk (or cause very slow long term problems that would be missed).
the precise cause of ME, could have been with us for tens of thousands of years, and adapted to us, and is thus not at all obvious. A retrovirus from rodents would make sense
Rodents = granaries etc...
And the human body is awash in bacteria and virsuses, many of which we do not understand or even have discovered, as yet.
We're the product of about 4 billion years of evolution. Bugs are a lot smarter and common than you'd imagine
If AIDS hadn't killed quickly, there' be almost no damn work on it initially and for a long time after, because it was a disease of *
insert nasty bigotted names here* so there was a deliberate blanking out of the issue, hence hard fact research got stonewalled by the bigots in US government/religion, and there was in the very early days confusion about WTH was going on with the victims, as it wasn't killing by direct action, but by immuno suppressance etc.
Hindsight makes it all
ooooh so clear and obvious to us now about AIDS, but back then, lot of folk had their head up their asses and got in the road of those trying ot understand AIDS.
So, 100 years form now, folk may look back and wodner why we were so stupid and unable to see ME was caused by a "stealth" retrovirsus that 20% of the populaiton had and that caused a wide range of problems depending on the individual's further infections, genetics, etc.
It's possible the base cause of ME coudl be responsible for a great deal of Human health problems, just liek herpes causes lot more harm than just "cold sores"