You need to get a proper spray that you can de-flea the carpets, furnishings ect. Fleas can live in carpets for years. I remember going to stay with a friend and I noticed a flea that had landed on my leg when I was sitting in his living room one night. He had never had a cat. My neighbour`s daughter worked in a vet`s surgery and she told me about an industrial strength spray you can get for the house. I can`t remember the name of it but it was expensive (£7 about 7 years ago) but it was worth it. Failing that, you might have to get a professional in.