Mattresses are considered to be the main source of house-dust-mite (HDM) allergen. This study aimed to investigate different types of vacuum cleaners for their ability to reduce this allergen reservoir. Three types of vacuum cleaners were examined: a conventional vacuum cleaner, a water-trap cleaner, and a central vacuum cleaner. Cut out pieces of mattresses were analyzed for content of mite allergen after vacuum-cleaning. Three polyester mattresses from the homes of three children were selected for the study. These three mattresses had earlier been found to be contaminated by group 1 HDM allergen (8-15 mu g/g of dust). Each mattress was divided into three main sections, separated by a safety zone, and each main section was subdivided into four parts. The three main sections were cleaned by each vacuum-cleaning system. Pieces 2-cm-thick of the surface of the mattresses were cut out, and extracts were made to assess the amount of mite allergen still present after different intensities of vacuum-cleaning. A considerable reduction in the level of mite allergen was found after using all three of the vacuum-cleaning systems. Only 22% of the original mite-allergen reservoir remained after intense vacuum-cleaning. Since the number of mattresses in the investigation was low, and niche formations of group 1 HDM allergen within the mattresses were observed, the results must be interpreted with caution. Furthermore, allergen-producing living dust mites were not affected by this method. However, intense vacuum-cleaning seems to reduce considerably the level of the mattress-bound mite-allergen reservoir, a fact which may be important in mite-allergic and mite-exposed families.
