I don't mean mummy-rot here; do any of you use diseases in your fantasy games, in the non-magical sense? Like the plague rolling through town, or injuries getting infected?

RPGPundit

I do. Though it does depend on the game.

Now and again, but mostly just as a consequence of tussles with particularly squalid sorts of creatures, less often a plot point.

Not really, but my players have picked up lice in a Warhammer Fantasy game.

As for Infection rates, I use them on occasion. Usually, it's an aspect of a weapon. Inferior weapons tend to break off into the flesh forcing infection checks, but are more likely to break and deal less damage.

I had fun designing diseases for our Clockwork & Chivalry game - I based them on real-world diseases as understood in the time the game is set (so no germ theory - disease is caused by miasmas, hellish forces, or imbalances of the humours). I use them for atmosphere, but don't really like to hit the PCs with them (although they know to steer clear of anything with "unpleasant miasma" in the flavour text...).

Only when the PCs do stuff like drink untreated swamp water or muck around in sewage, and even then whatever disease/infection they pick up is most likely to be more of a nuisance (temporary stat-drains, unable to adventure for a period) than a deadly threat. Deadly diseases are only likely to be picked up from monsters, spells, or curses. Epidemics like plague and flu generally only affect NPCs and occur offstage, unless it's a direct plot-point (i.e. the PCs need to stop the spread of the disease, or specifically deal with some consequence of it).

I like the super-detailed treatment of diseases right at the front of the 1E AD&D DMG because it's a (presumably unintentional) object lesson in house-ruling to all would-be DMs reading the book - when one of the first things they encounter is a set of super-fiddly and over-complex rules that almost nobody uses (certainly nobody I've ever played AD&D with), it immediately sets the tone that "this book is full of all kinds of rules, but you're going to pick and choose which of them you actually want to use," which is one of the most valuable lessons that needs to be learned by any 1E DM

I have been toying with sepsis mechanics for historical settings, to really drive home the threat of infection after combat. It isnt something i would recommend if you want reular fighting, but in a game where combat is more of a last resort it can definitely add something. Setting the rates of infection is the tricky part and i am still trying to balance what is relistic versus what is practical in an rpg.

I've had rules (which I plan on simplifying,) but it hasn't come up in play. Ranging from common cold on up. Primary effect of illness in my games is that you can't heal anything else until you're over the illness.

My primary thinking on *catching* disease is that it should mostly show up when the players fail or are unable to practice avoidance or precautions. The characters may actually be getting sick from time to time, but they're heroes, so most of the time they just ignore the aches and pains. It's only the exceptions or the significant side effects that are worth noting.

i've used things like bubonic plague and cholera in games before to varying degree of effect.

I've included parasites more often than diseases, though the distinction is rather gray in historical settings.  In fantasy and science fiction settings, parasites come up mostly for dramatic effect, since players have a real reaction to them that they do not have for diseases. I have included diseases in my 4th edition campaign too, as environment terrain hazards to use 4th terminology. I had to include the 4th terms to ruffle feathers here.  Silly.  I have also added some high level diseases to lowly swarms of rats that high powered characters even in 4th took notice. Some of the stronger recurring AD&D 1 parasites I've used were Cerebral Parasites in a campaign that involved psionics. Edit: Speaking of the 4th diseases rules reminds me of how annoying it was that erratum were almost immediate set for the difficulty checks.  I didn't appreciate the going back and forth on the set difficulty ratings over all.  Can't DMs easily set those themselves based on their campaigns?  Never got the need to always monkey with them.

Depends on the sort of game really, high fantasy is often disease-free, but it makes an appearance to one degree or another in almost everything else. Warhammer would make extensive use of disease for example, being gritty and dark.

Generally my preference is to include it, although maybe not as regards infected wounds, more like signature diseases the area is known for, unless we're in a plague scenario.

Now that I think about it though there could be room for the inclusion of minor irritants, like a penalty to all actions if you have a cold.

My Medieval games are full of diseases - cholera, typhus, the plague, leprosy, all the ills of the world.

My Fantasy games less so, as a good Cure Disease spell fixes them fairly easily.

Yes.
I use it.  It is actually important as a differentiator as to the relationship with magic and magical healing to the setting.  

Sickness and Disease.

The rules in Aftermath for diease incubation and vector of transfer helped get me through O level biology if that is relevant.

Was one of those amusing moments when I was reading the rule book instead of listening to the teacher and he called me to the front and did the old, so you think you know all about this subject blah blah and asked me to explain it to eveeryone else. As I had just been reading the Aftermath rules on just this topic, well that as the effect of laser trauma and the vapourisation of water in cell tissue I was able to talk fluently on the nature of different vectors of disease, incubation periods and fatality rates for a good 6 or 7 minutes before he asked me to sit down pretty funny.

I should point out that since I use disease, I have spells that deal with it.  While Necromancy is not always evil in Celtricia, Death Magic is always a faux pas.  

http://celtricia.pbworks.com/w/page/62279763/Unhealth
http://celtricia.pbworks.com/w/page/14955677/Instigate%20Disease
http://celtricia.pbworks.com/w/page/14955346/Blade%20of%20Contagion
http://celtricia.pbworks.com/w/page/14955345/Black%20Cloud
http://celtricia.pbworks.com/w/page/14955675/Instigate%20Disease%2C%20Greater
http://celtricia.pbworks.com/w/page/14955676/Instigate%20Disease%2C%20Plague