It's all on his web site at http://pages.britishlibrary.net/tawney/enter.htm:

"Cyril has been unwell since October 2003, starting with diabetic leg ulcers, but during 2004 he developed various other symptoms, went into hospital in April for a couple of weeks, back in again in July, and he's been there ever since. His case is very involved and it took a long time for the medics to be able to determine the underlying cause of his several problems - the main ones being bone infection with symptoms which include swelling, with softening of some of the bones, and nodules. The leg ulcers continue but are probably unrelated to the main condition.


"The culprit is Mycobacterium Cheloneae which is commonly carried in water but rarely enters the body."