If I was you I would keep an eye on the other cats and treet where needed
also keep on eye on yourselfs as humans can easily catch the problem.

Googled 'feline ringworm'...

Lots of informative sites.  Here's a few:

http://www.sniksnak.com/cathealth/ringworm.html

http://www.hdw-inc.com/healthringworm.htm

http://jewelry4u.photovault.com/feline-ring-worm.html

http://www.marvistavet.com/html/body_ringworm.html

HTH!

Many/most adults already have been exposed to the ringworm fungus
which is present in soil. If they are healthy, if they get it at all
it will be mild. Usually treatment with a topical is enough. My vet
recommends the athlete's foot remedy, Lotramin, in the oil base for
better penetration. Humans are usually easy to clear also. I've used
the lotion and covered it with a bandaid.

If I have ringworm come in the house with kittens, I give everyone a
large dose of Program as a preventative and I keep the kittens
separate of course. That's what I would do for your other cats. You
can buy Program for dogs in 400+ mg size and treat at 100mg/kg, every
two weeks. Grind up the tablets and mix it with food. It is almost
impossible to overdose with Program (lufenuron).

Kittens who get ringworm may require more aggressive treatment.
Here are a couple of sites:

http://www.pandecats.com/x/ringworm_battle_plan.htm
http://www.pandecats.com/x/limesulphur_shampoo.htm  

BarB