Yes; it is excellent!
I had ringworm amongst my 16 piggies at the beginning of the year - the logistics were a nightmare (especially all the washing at hot temperatures, including the towels bathing all piggies), but I managed to contain the spread to just two of them.
As you have had it for a while, separating is not necessary; rather treat all piggies living together with a fungal dip for three times.
The important thing with ringworm is to make sure that all affected hairs come out - ringworm can come back otherwise (imaverol is excellent for that purpose); the affected area with any kind of fungal is usually bigger than the visible area. At first, it will look like it is getting a lot worse because of that, but then it should clear up pretty quickly and they should be over the immediate acute phase within a week or 10 days.