I have a hard time believing that scruffed knees led to that infection unless you were immunocompromised. There was no infection around your shins? Were you sick previous to this?
Either way, it seems like some are deathly afraid to even lift. It is a community area. Treat it that way and get on with your lives. Wash your hands when you get done. Quit playing with your faces with your hands. I admit that people coughing into the air truly pisses me off, but our bodies are generally not that fragile. We are exposed to minor pathogens all day long. If some of you could see the crap that we actually sleep in daily, most would change their bed sheets every single day.