If you haven’t heard of this one, you should be aware of what it is and what it can do.
Leptospirosis (Weils Disease) is a possibly fatal disease which can be spread by rat urine in river and canal water. Four people have died from it in the last five years, including an Olympic rower and an acquaintance of mine who lived on a canal boat. You can see the water connection here.
The disease is treatable if diagnosed early enough. Initial symptoms are mild flu-like symptoms which if not treated can go on to severe problems which can include liver and kidney failure.
Apart from this though, don’t forget to descale and sterilise showerheads. This helps to prevent another water borne disease – Legionnaire’s Disease, which can also be fatal.