Effectiveness of vacuum-cleaning in removing Fel d 1 allergen from cotton fabrics exposed to cats.

Background: The major cat allergen, Fel d 1, is ubiquitous, and clothes of cat owners are important vehicles for its distribution and dispersal in cat-free environments.
Objective: We assessed the efficiency of a standard vacuum-cleaning in removing the cat allergen from cotton fabrics, experimentally contaminated by a prolonged contact with cats.
Methods: Fifteen rectangles (80 x 100 cm) of a widely used cotton material were kept in baskets of male cats for 1 week. Afterwards, the squares were cut in half. One half was immediately sampled for cat allergen, and the other half was vacuum-cleaned for 15 minutes by a commercially available device before sampling. Five identical cotton rectangles not exposed to cats served as controls. Samples were collected with a high-volume vacuum air-sampler. Particulate material was harvested onto filters with 25-mm diameter and 2 microm pore size, extracted in phosphate buffer with BSA and then assayed for the Fel d 1 allergen with an ELISA method. The results were expressed as micrograms of allergen per filter.
Results: After vacuum-cleaning the amounts of Fel d 1 extracted from cat-exposed fabrics were not significantly reduced ( t = 3.118; P > 0.005), with respect to the non vacuum-cleaned tissues. No Fel d 1 was found in control fabrics.
Conclusions: Our study suggest that vacuum-cleaning by using a commercially available device is not able to remove significant amounts of cat allergen from cotton fabrics exposed to cats.