HOUSE-DUST MITE (DERMATOPHAGOIDES-FARINAE AND DERMATOPHAGOIDES-PTERONYSSINUS) PREVALENCE IN THE ROOMS AND HALLWAYS OF A TERTIARY CARE HOSPITAL

Background: House dust mites, Dermatophagoides farinae and Dermatophag oides pteronyssinus, are important components in the development of as thma. Objective: We measured the prevalence of house dust mites in a t ertiary care hospital located in a temperate geographic region where d ust mites were prevalent in homes. Methods: The density of Dermatophag oides spp, was measured in hospital hallways, carpeted patients' rooms , and noncarpeted patients' rooms by vacuuming the floor in the summer and winter seasons. Bedrooms in the homes of employees were sampled a s a summer control group. A total of 141 dust samples was obtained.Res ults: No D. farinae or D. pteronyssinus was found in 60 hospital dust samples that were obtained during the winter season. Although mites we re found in some locations in the hospital during the summer dust coll ection, mite density in these locations and the average mite density f or all samples were insignificant During the summer dust samples from the bedroom carpets of all employees' homes sampled were positive for mites, with many homes having moderate or high populations (range, 22 to 8340 mites per gram of dust). Conclusions: The dust mite prevalence in a hospital could be kept very low even though mite levels in emplo yees' homes were moderate to high. The factors responsible for the low mite density in the hospital were maintenance of low relative humidit y use of low-pile carpets, and good housekeeping and laundering practi ces.