It's been so many years since he announced that he was terminally ill that I just assumed he had already died, as I haven't heard anything about him for so long.
In a way, he had already died; BBC News has just told me that it happened on Friday and he's already been buried/cremated.
WARNING: It can be much worse...
Symptoms can range from none at all to a mild flu-like illness, or a more severe illness called Weil's disease, with jaundice and kidney failure. In most cases, with antibiotic treatment, the person will make a complete recovery. But for a few, it can be fatal...
What size pipe feeds the cistern? If 22 mm you don't need to turn off the water at the mains (use gate valve instead). If 15 mm, then why not fit an isolator valve beforehand? The ones without handles are quite cheap.