I'm traumatized from seeing a security guard get poked with a used needle earlier today

Some tweaker-looking dude kept lingering around outside our department and it was getting real suspicious, so we called security to come deal with him. The security guard who showed up recognized him as a guy who's been busted for drugs around our casino before and as he was searching him, sure enough, the guy had drugs on him. I was watching him continue to search the guy when he immediately pulled his hand away and when he looked inside the pocket and said "Nice." I asked him what was wrong and he told me he got poked with his needle. Seeing his finger bleeding like that made the gravity of the situation hit me real hard. I let out a "God damn it", but did my best not to freak out and told him to keep it bleeding as much as he can. He was keeping his cool but I could tell he was worried. I gave him some hand sanitizer to clean it real good. Police showed up quickly, thankfully, and after he turned that junkie over to them, the guard called our workplace's health services and took it from there. That was real scary, I'm still shaken up from it. I can't imagine how the security guard feels. Here's just hoping for the best.