I just never really had a lot of people with the need to touch my kids when they were little bity, I did have tons tho that wanted to get in their face, which bothered me more than the touching.
The times that I did, if they looked fine then after they left I just used a wipe real fast on my little ones hands, but if they didn't look to clean or they just made me nervous then I just said that my little one is finally getting over a cold I just don't want to chance her getting sick again and they were fine and almost all of them were really understanding about that. I also say that even tho this one isn't my first I'm still like a first time mom, and just nervous about everything. Most people just kinda chuckle and tell me not to worry before to long i'll be "an ol pro". I think that works because then you're putting it on yourself and not on them, know what I mean? The looking busy with your little one is another good one too.
Also, I'm one of those baby lovers. I just love little babies, and who couldn't? However I HARDLY ever touch and I NEVER get in the face of anyones baby, and if I do feel the need to I ALWAYS ask if I can say Hi to their little one and if they say sure then I pull out my own hand-sanitizer, but even then I don't "paw" all over their little one. I ALMOST always just smile at the new mom and tell her how just too cute her new little one is while hardly even stopping.
My six year old is one of those kids that always wants to touch, hold, hug and kiss little babies. He stops me when he sees one WAY more often than I do. When he sees a baby he'll ask me if he can go say hi to the baby and I tell him that he MUST ask the baby's mommy FIRST and that he CAN NOT touch the baby becasue he may have "sick" germs on him and that we don't want to give any "sick" germs to the baby. He's VERY good about that and most moms thank me for teaching him to ask first and to not touch and then tell me how sweet he is.
I would try to be polite, kind and frim with people, then if you're dealing w someone who just doesn't get it then get a little rude if you need to.