Stuck in a rut with contamination

It seems like everywhere I go shopping lately almost all the cashiers that ring my stuff up have a bandaid on their finger. I know it's probably going to keep happening until I just don't care but I don't know if that'll happen. I threw away a 2 lb. coho salmon last week. I went to the fish market and the lady behind the counter was chatting at the register when I got there. She didn't wash her hands before getting the salmon. She took a plastic square thing and grabbed it and then she put a couple sheets of it on the scale which she got her germs on. She also had a small scab on the outside of her hand. I thought I'd be fine with it but I worried about it the whole evening and next day and then decided just to throw it away. What a waste of $20.00.  Today I went to get a new purse since mine is literally falling apart. The women who rang it up had the end of her thumb wrapped with white tape. I really want to use the purse because I need it and I don't want to return it. I had a hard enough time choosing it. It is my basic black of course. I can't get myself to buy one with that silica gel packet stuff they put in them and I found one that doesn't have it. I made sure I looked inside and made sure no one put any garbage in it or anything. I always check the stuff I buy for blood or any stains or whatever I'm looking for. Now, I feel like my purse it contaminated though. OCD can really take up so much time. Things other normal people just don't even think about. I also threw away a whole bag of frozen broccoli this week because when I was cooking it I noticed a browinsh spot on a piece and was afraid it might be blood. I know I can't just keep throwing stuff away.