Well, I was not aware at any time that I had a chronic, low level infection. I got the occasional cold much like everyone, coughed quite a bit in winter, which I put down to the materials used in my profession, nothing more. Having a chronic infection does not necessarily mean that you are permanently aware that something is wrong. I went for years with MS basically so benign I didn't even realise I had it: several years between attacks, then complete recovery. Then I hit my forties, got a second acute infection and things straight away started to unravel: I went within a few months from being able to do a 20 mile plus trek and not even feel tired to not even being able to walk to the post box, a few yards up the road.
Magpie found the reason why many women feel great during pregnancy and I can't argue with that. If the infection does not ordinarily make you aware of its existence, why should it be any different during pregnancy?
Why has chlamydia pneumoniae been only so recently discovered? Because it is so damned hard to find is the reason. Many laboratories are still finding it difficult after 20 years and most neurologists won't even countenance that MS might have an infective cause, as was thought back in the 19th century. Too many years have passed without the infection being isolated. And this isn't the neurologist's job anyway: medicine has become so specialised over the years and there is so much to learn in each speciality that many things are just being missed. There used to be a post in all hospitals called a 'general physician', whose job was basically to link everything together. There used to be one here when my husband took up his post in 1980 at the age of 29. He was very old, he retired not long after and was never replaced. Several years later I left university and developed MS, then C Pn was discovered to be a pathogen but there was nobody to link everything together.................until now.