Many thanks for your quick response. I know it is mad thinking this way. The reason I am asking is that last week I was having my hair cut at the barber shop. I am sure that I saw the barber using a new blade (razor). However while he was shaving my head he nicked me with the razor. The cut was slightly bleeding (not massive). My question is that, can this type of cuts be risk if they were exposed to fresh infected blood? And for infection to happen how deep the cut should be to be considered a risk?