There's no known cure, it's highly contagious and those who are most riddled with it are often the healthiest. It's the running bug of course. I caught it about eight years ago when I found myself working for a sports organisation (writes SCOTTISH RUNNING GUIDE's Chris Broadbent).
Running was at epidemic proportions and I couldn't help but catch it. I have never sought treatment - it's the one ailment I've truly enjoyed. It has given me new experiences and emotional highs that I didn't believe such a simple activity could do.
Perhaps what has given me even greater satisfaction is passing the bug on. In recent years, many of my immediate friends have taken up running. None of them I could have predicted would be runners. Now several of them have half marathon, marathon and triathlon medals tucked away in their sock drawers. It's never been acknowledged, but I know that my own involvement has been a definite influence on them.
Sometimes it starts with a phone call, often just after the turn of New Year. "Got a favour to ask you." they say. "You're a runner...and well, I've been thinking about doing this race. Do you fancy it? I could also do with a bit of help with training too. Can you help?" I'm always chuffed whenever people make this call. I recognise the nervousness of it from my own early experiences. I also know that the fun that running has brought into my life, my friend could bring into theirs. Even better, we can share some of these experiences together.
It doesn't end there either. One friend in particular has just entered his third marathon - Kielder in Northumberland, having bagged his first 26.2miler in Brighton and followed it up in New York last year.
Now, some of his own friends have started to catch the bug off him. Two marathon virgins have entered Kielder alongside him. The running bug has started to run amok again and luckily, there is no vaccine.