Ringworm.

I got my cat Moe, 3 weeks ago from a shelter. He had ringworm, but they assured me he was all cleared up, and was ready to be adopted. Well, last week, I noticed my boyfriend and I have it. I have about 4 sores, but I've been treating them, and they're clearing up. But the other day I noticed my cat puzzle had it (he's almost cleared up now). I called the place, they said just to put the cream I was using on myself on him. The next day, Gigi had it, and bad. She lost all the fur above her eyes, and all on her ears. She's been licking the cream off, but the vet assures me that it won't hurt her. Now Moe has it again. I'm going through a tube of anti fungal cream a day. I have 5 other cats that don't have it yet. Is there anyway I can maybe prevent them from catching it off of the 3 that already have it? It's aggravating, it feels like its never going to end. I feel like, once one cat clears up, another one catches it, and then the ones that are cleared up are just gonna get it again, like a never ending circle.