Yeah. I also wondered about a trigger difference. EBV to ME than for SARS-2 to long Covid.
But when I had EBV, this came with massive lymph swellings and a high temperature. I thought this was characteristic?
Yes that is my understanding as well. A high temperature, lymph swellings etc are all the main characteristics of glandular fever, but they are not the main characteristics of ME/CFS.
I think I expressed myself badly above. What I was trying to say is that the main characteristics of the acute illness (fever, cough, high temperature, discoloured mucus, massive lymph swellings etc), i.e. the trigger, are not the main characteristics of ME/CFS. This holds for both Reiters and ME/CFS and the respective illnesses/triggers that cause them (at least that is my understanding). The problem however on the opposite side is that the main symptoms of Reiters are also not part of the acute illness (at least if I'm assuming correctly), whilst the main symptoms of ME/CFS are often tend to be part of the trigger as well (fatigue, cognitive problems, muscle pain etc).
So identifying a "recovery period" similar to Reiters might not be possible in ME/CFS simply because there is a larger symptom overlap in ME/CFS with the trigger rather than having something to do with a time duration of an immunological response.
I'm wandering whether such problems could possibly be dismanteled by approaching the problem slightly differently, which might however require rather smart and careful investigators. For instance one could only look at a specific symptom that is believed to be a central part of ME/CFS but doesn't appear very often in certain ME/CFS triggers. I was for instance specifically thinking about onset brain fog/cognitive problems in ME/CFS after Covid because my understanding is that the current Covid variants don't cause brain fog in the same way the initial variants did in a population with less immunity. The problem here is of course that ME/CFS after Covid isn't well characterised and additionally that ME/CFS after Covid appears to be becoming less common. Additionally doing it retrospectively could also introduce bias.
But if you'd have a study that showed people with ME/CFS and cognitive problems develop brain fog after a period of recovery or even don't report it as part of the acute illness than that could be signal for this specific symptom to underly a certain dynamic. Alternatively you might find out that only people that also have brain fog as part of their acute illness also develop ME/CFS with brain fog and that there is a "recovery period" from brain fog or that there is no "recovery period" from brain fog and that it is rather constant which would point at different dynamics. I would expect the results to be somewhat heterogeneous, but someone smart might still get good data if such a study was carefully conducted.
I don't know whether something similar could be done with EBV/glandular fever because my impression is simply that the glandular fever episode appears to be longer lived so that it all becomes rather muddy, but maybe someone smarter can work something out. I believe Scheibenbogen is part of a study that follows teenagers in Germany that have glandular fever and studies the relationship to the development of ME/CFS. I thought brain fog might be the better symptom to study rather than PEM in this instance because PEM as part of ME/CFS and fatigue as part of acute illness triggers might be too similar but I could be wrong about that. A rather obvious hurdle here could be that no one has characterised the cognitive problems reported by pwME...