What is the most effective advice to avoid/minimise risk of illness when travelling in Africa?

I'm considering some trips to Africa at some point in the future and a major concern is protecting against illness.

Obviously, as with other places, the continent varies a lot: cities, rural, villages. So the advice would vary as risks will be low in some areas and high in others - as is the case on other developing continents.

And don't get me wrong I'm not singling out this content as being the only one where one should be careful, this would apply to other regions where such risks can occur.

Taking official advice on vaccinations is fairly straightforward and advice on Malaria is well documented (but any points welcome).

My Specific Question

My question is more about other risks. It is perhaps easy to get carried away with over concern about these, particularly as many are quite unpleasant, e.g. parasites in the gut, legs, eyes etc. Various TV programmes and websites can scaremonger. But how much of a risk are these really?

I regard travel.stackexchange.com as quite a high quality forum, where the signal to noise ratio is very high and comments are generally sensible. So I'm looking to see how contributors could answer my question. The decision on risk is ultimately mine of course.

As this site guides questioners to ask solvable questions, then my question is can you provide definitive advice on the risks:

• what risks are current
• where do they occur (rural, urban, semi rural, regions?)
• preventative steps ( vaccinations, avoidance of certain foods (e.g. veggie only, wash foods, hygiene, boil/steriliser tablets to make water safe to drink)
• symptoms to look for
• treatment (though I'd prefer not to get to this stage :) )

Some research I have done so far:

Parasites: how acquired, symptoms and remedies:

(If I'm honest this is the kind of thing I'm most concerned about, perhaps a moderate phobia of, I don't think I'm alone in that. Apart from the risk itself, I think my attitude is also something would have to consider).

Delicious.com stack: http://delicious.com/stacks/view/TelRyi

Some seemingly good advice:

• https://www.lonelyplanet.com/thorntree/thread.jspa?threadID=1441534
• https://www.lonelyplanet.com/thorntree/thread.jspa?threadID=1512030

Others (fairly thought provoking, if sometimes unpleasant stories, a bit more anecdotal):

• https://www.lonelyplanet.com/thorntree/thread.jspa?threadID=1779942
• https://www.lonelyplanet.com/thorntree/thread.jspa?threadID=1480034
• https://www.lonelyplanet.com/thorntree/thread.jspa?threadID=1455845
• https://www.lonelyplanet.com/thorntree/thread.jspa?threadID=1365291
• https://www.lonelyplanet.com/thorntree/thread.jspa?threadID=1908527
• https://www.lonelyplanet.com/thorntree/thread.jspa?threadID=2019005
• https://www.lonelyplanet.com/thorntree/thread.jspa?threadID=1379159
• https://www.lonelyplanet.com/thorntree/thread.jspa?threadID=1466554

Malaria:

• https://www.lonelyplanet.com/thorntree/thread.jspa?threadID=1811844