Detection of dust mite allergens in homes throughout the US

Abstract

Dermatophagoides dust mites are known to vary across North America depending on location with factors like elevation and humidity influencing their presence. These studies have included microspopic identification of mites, DNA analysis and allergen protein measurements. In order to develope a current mapping of allergen protein prevalence, we have studied dust from homes in 16 regions around the US for major dust mite allergens. In order to explore variability within a region, multiple homes from the same region were studied. Dust from vacuum cleaner bags from 24 homes was used to make 1:10w/v extracts using a 1% albumin, 0.9%saline phenol extraction fluid. The extracts were filtered using a 0.2micron filter then analysed for species specific Der p/f 1 using direct binding monoclonal ELISAs (ALK, Madrid). Nineteen of the homes had detectable mite allergens ranging from below 1 microgram/gram of dust to more than 20micrograms/gram. 12 of these homes showed D. farinae only, 1 in Southern California showed D. pteronyssinus only, and 6 homes contained both mites. The D. pteronyssinus containing homes were not confined to coastal areas. The homes in Spokane, Reno, Denver, and Sonoma showed no mites. Out of 9 homes in Texas that contained mite allergens,one had no detectable dust mites. This study confirmed widespread presence of dust mite allergens in homes across the US but are low in drier rocky mountain states. Many homes contain both species in New England and Southern regions.