Cambridge malaise

I was a student here at Cambridge many years ago, and having returned recently I now remember one of the more unpleasant aspects of living here. To quote my brother, "everyone is ill, all the time". I'm just recovering from my fourth cold/flu of the season, and am keeping my fingers crossed that I don't get any more. I've never figured out what it is about Cambridge that makes it such an unhealthy place to live. My mum was amused to read a quote in a newspaper article from the twelfth century, complaining that people in Cambridge can expect to be ill throughout the whole winter, finally recovering again when spring arrives. Isn't it nice to know that some things never change!