Some things I'd consider:
Gi only grapplers, have you ever come down with ringworm, staph, molloscum, or other common grappling related skin issues on areas of your body covered by the gi? For example, if you religiously wear gi pants, have you ever had staph on your knee?
No gi guys who wear a long sleeve rashguard, have you ever suffered any of the above on the covered areas of your body?
Everyone I know trains in both, making a distinction impossible. Those I know who've had staph have had it on exposed areas of their body where the skin was open (cut, matburn, etc) prior to infection.
If you have picked up anything on an area you know was covered by clothing, I would like to hear about it.
Pat Militech had an interesting take on the staph outbreak in his gym, in a FIGHT! article. Mentioned that he has 50 fighters, and 200 normal people in his gym, all using the same mats, gear, etc. He had something like 8/50 of his fighters sick with staph, but none of his normal people got it, leading him to believe that transmission is highly linked to very close person to person contact. That's from an article I read a few months ago, it's not a perfect recollection by any means.
