Comparison of the domestic mites abundance in dwellings on selected urban and rural areas of the Zawiercie district (south-west Poland).

Mites are found in all types of environments, inhabiting also the immediate human environments, including dust from sleeping accommodations, upholstered furniture or carpeted floors. It is commonly known that house dust mites are sources of potent inhalant allergens. Dermatophagoides pteronyssinus and Dermatophagoides farinae belong to the most common species in the temperate climate zone. Samples were collected by using a portable vacuum cleaner, into trap-filters installed onto the cap for dusting. Then, mites were isolated by a flotation method with saturated NaCl solution. The Petri dishes were screening under a stereoscopic microscope for presence of mites, then isolated mites were mounted on microscopic slides in Hoyer's medium. Mites were identified to species under the light microscope using phase contrast optics. A total of 724 mites were isolated from 46 of the examined samples, including 666 (91.9%) members of the family Pyroglyphidae. Among them D. pteronyssinus was predominat (62.8% of the total count, with average number 211.22 specimens per 1 gram of dust), followed by D. farinae (24.03%, averagely 150.07 specimens per 1 gram of dust) and Euroglyphus maynei (4.42%, 118.11 specimens per 1 gram of dust). Higher density of house dust mites was associated with the following factors: higher age of building, higher number of roommates, higher washing frequency per week, presence of carpeted floor in bedrooms, wooden floors in kitchens, closed kitchen, uphoplstered furniture, absence of pets and unemployed housewives.