I actually think this is exactly what is happening in many cases of ME/CFS: some underlying immune dysfunction is permitting various pathogens to persist in the body. Many, many pathogens - viruses, bacteria, and fungi alike - have been in some way correlated with ME/CFS, and I think the most parsimonious explanation does not chalk up multiple infections to coincidence. Mold is extremely common, and I imagine a healthy immune system essentially fends it off. But without that protection, it would really only be a matter of time until a person acquired a mold infection in some form.
I think there's definitely some merit in treating mold if it appears to be present, but the optimal treatment strategy is probably multi-pronged. A lot of the factors in ME/CFS are probably bidirectional. For instance people getting mold infections due to immune dysregulation, but also mold infections (or other infections, or bacterial dysbiosis) causing immune dysregulation. Treating the mold alone may lead to relapse if the immune dysregulation persists, and treating the immune dysregulation may not work if particular infections are not targeted at the same time.
This is a good point and something that could well be the case. Perhaps it all starts out by a disruption to the microbiome (caused by overuse of antibiotics, an infection, a poor diet, anything) which then weakens your immune system, making you more susceptible to moulds taking hold.
But that doesn't mean the mould isn't be the root cause of the
symptoms. It might mean that recovery entails both removal of the source of mycotoxins and, say, restoration of the gut microbiome to prevent relapse, but both stages are surely equally important.
And as the author of the report states, the incidence of 93% amongst CFS sufferers is clearly too high to just put down to chance alone; it's a ludicrously high figure when compared with the healthy subjects, even if none do recall any history of living in WDBs. It seems to me to be an obvious place to start, no? There could of course be loads of reasons why it isn't the crux of someone's CFS, and I've no doubt there are multiple different causes, there is clearly no one silver bullet or else none of us would be here. But we're all here looking for clues and this seems like it might be a mighty huge one, even if it is one that's combined with say, gut dysbiosis or SIBO or some sort of infection.
At the very least it's incredibly likely that having high levels of mycotoxins doesn't help your health - here's the author's experience of treating his patients:
"He has had some patients dramatically improve and is now doing some retesting. None have gotten their mycotoxin levels to zero but some are close. There is a direct correlation between mycotoxin level and state of health."