Thank you for being so supportive and patient.  And, of course, knowledgeble. Despite the fact you have said I can post a follow up, I thought paying for another question was the right thing to do because this is not for me. It is for my sister. I told her about this great site and about the information you have given me. She asked me to ask you about the following:

3 months ago, she went for a laser cosmetic treatment. Her skin was inflamed, but not bleeding the next day. Nor she could feel any stinging when she would rub alcohol on the spot. Basically, during that procedure, they put micro holes in skin..very, very tiny and when they heal, those holes are supposed to improve collagen production. It is called fractional CO2 laser. The holes are so tiny, they supposed to close very quiclky. She did the procedure on her arms. The very next day after it (about 16 hours later) , she met a friend who came to visit and say hello.  She (the friend) had spots on her arms , but they were not bleeding. She hugged her friend, so the friend's spots touched the area where my sister had the laser procedure done the day before. 

So her question is this: is this a risk for something? Both of them were not bleeding, she did not see blood on her arms after she hugged the friend too. 

Based on what you have told me, I said she should not worry because a) her skin was probably closed if when she rubbed alcohol it did not sting b) if she did not see any blood, then it could not had been enough amount of blood passed between them even if her friend's spots were not scabbed over and were a couple of days old only c) the chances her friend has hiv or hep B/C are very low. She is married and does not appear promescious in any way d) 3 months passed, and she did not get any symptoms of seroconversion. Neither did her friend. 

What do you think? Thank you again

Olga