Touching my baby

I live in a city where people (strangers) think it’s okay to mess with my baby while we are in a store or out to eat or anything.. they will grab him hands and touch his face and head like wtf no stop I don’t know you.. then they will continue to kiss his hands... or when I’m at doctors appointments little kids will run up to him in the stroller and mess with him I look at the parents and shake my head because their sick kid is touching my baby and they smile and tell me oh they’re just playing! I take my baby elsewhere in the room and say no because I don’t want him to get sick especially in flu season..I don’t even hide that I germ-x him right after I do it in front of the people now.. he got sick when he was first born because someone put a finger in his mouth and trust me that’s not gonna happen again.. it really pisses me off..