Ooh - I do know how you feel - I'm itching as I type this!!!
I was in the same situation as you - but it seemed that with the cats and dogs frontlined, the fleas would feed from us

!
Remember - for every flea you find on the dog/cat, there are 10 in the carpets
We tried everything - from smoke bombs, to calling out a pest control company - they used a product called Acclaim Plus (I think!!) - but instead of doing it the way that we would use it - ie - vacuuming the carpets, using the stuff and then vacuuming again the next day, they vacuumed, used the stuff - and then instructed us NOT to vacuum for 7 days - they returned after the 7 days, vacuumed again, then resprayed. It was an improvement - apparently leaving it for 7 days caught those larvae that were just about to hatch. However, we only really solved the problem completely when we took up all the carpets.
I might find an occasional flea on Buster, the Rasta cat just as he's due to be frontlined, but no more being bitten every time I go into the dining room!!!
Margot