It is with some sadness, I have to tell you all that I am not quite the man I used to be. Possessed of a solid freestone heart, I imagined my immune system to be sturdy, impervious, I thought I could resist but alas not. I have been infected and fear that there is no cure. Read on and learn - if you can - from my mistakes. I have illustrated the causes, the symptoms and the effects as graphically as I can and offer no apologies for the message that they contain.
The Oxford Advanced Learners notes a serious condition thus:
chron•ic /kr>n

k; NAmE kr


n/ adj.
1 (especially of a disease) lasting for a long time; difficult to cure or get rid of:
chronic gallopingchalkstreamitis/ acute
The early signs are easy to spot but you are unlikely to be aware of their tragic portents. Environments such as those below are typical breeding grounds for GCsI.
It all looks innocent enough doesn't it? Don't be fooled though... put your rod back in your car and your foot to the floor. Don't look back... or stage two of the onset will speedily take hold.
Once your first fly has landed on a stream like this, you are more or less done for. The first indication of the next stage of your affliction is easy to spot:
A beautifully spotted wild fish which will cause involuntary spasms of the cheek muscles and spontaneous giggling.
Be careful too of the company you keep in such places. They may have been over-exposed to these high-virulence environments and be as such be way past the help of conventional practice. Typically these individuals are characterised by preternatural sensitivity to the presence of large wild trout and a heron-like ability to catch them at their leisure.
Clearly this pitiable individual has acute and advanced GCsI.
(Note the cheek muscle spasms are once again a prominent feature - something that time clearly does nothing to dispel in the condition).
By this time you start to feel affected somehow. You begin to fully understand the condition of your companion but this is no time to feel pity for the man, he is a dangerous and infective presence whose bankside proximity has changed your life forever. Nothing will ever be the same again
It isn't long before the cheek muscles start to spasm permanently:
And so you close the days fishing. Your mind is polluted with images of big wild trout, they are branded on your mind forever. Fish that dash through gravel shallows like leopards, cruise the chalk lagoons like crocs, or lurk beneath the cress like... like only big f*ck off wild trout can ever do. Actually, mostly they dash, and dash like you have never seen. You only have to think about twitching your line and these fish thought about it before you.
But you have more serious things to worry about. You now have an incurable condition and secretly, quietly you thank your companion for the infectious nature of his affliction. You have to hope in some crazy way that the condition which has now taken root in your blood will eventually induce in you the same heron like characteristics which your hapless companion displays so clearly. Only time will tell but for now you have got it very badly indeed - thank goodness for that!