My cfs started after atrip too, in my case in a zone known as an hotspot of lyme disease. It took me 10 years to understand that it was lyme and not cfs, the first test I did for lyme was specific for the American species and came back negative, finally the proper test for the 3 European species was done and came back positive.

That was pretty much a nightmare. With relatives and friends accusing me of being lazy whilei couldn't even walk.