In reply to GingerBread22:
Worrying, particularly if someones cuts themselves, common just above the nails and bleeds onto a hold..someone comes along and gets that into their own cuts.
Lets take a risk based look at this:
-How often do you cut yourself climbing? Probably not very often, which means the quantity of blood on a wall is quite small.
-Most blood transmissable diseases don't live very long outside the body which means only fairly fresh blood is a potential issue.
- How often do you climb with an abrasion or open cut that could lead to contamination? Probably not very often.
- What percentage of people carry a blood bourne infection?
- What is the chance of you putting this injury into a patch of contaminated blood? Very small.
- What are your chances of actually catching something assuming all of the above occur?
Small number x small number x small number x small number x small number = Tiny number
The total probability of actually contracting something nasty (say Hep, or HIV for example) are really vanishingly small and you are probably more likely to get killed by a falling bit of Voyager 1.
If you want to get worried then you should see the stuff I cough up after resetting the routes at my local wall. I should probably be wearing a respirator for shifting all the crud off the holds