I hate fleas….you can see my post on the "flea season is here". I have 4 cats and a bunny. I too have gotten fleas throughout my home from my rescue efforts.
Remember that w/ topical flea txs (Revolution, Advantage, etc), you need only apply once. The medication absorbs through the skin to affect body chemistry, this is what helps keep the fleas off and kills fleas that still feed.
Ear mites can be a common prob for kitties and buns. However, some body chemistrys make mites more likely or prone for some animals. Its important to get the official ear mites diagnosis from the vet, b/c as gravehearted stated it does need to be confirmed under the microscrope. Mites are basically nasty little bugs that thrive on the wax and gunk in the ears. My oldest cat, Max, had chronic mite problems as a kitten. These issues have led to acne-like blackheads inside his ears. They often become inflamed and bleed. He is also prone to yeast infections in his ears due to this condition. However, mites don’t necessarily spread through your fur household like fleas.
I hope the kitty is doing well. I fostered a kitten that suffered hypoxea (sp?) which led to braindamage and severe anemia due to excessive flea infestation. She only lived about 3 months…but that time was very special for her and me.