Antigen levels of Dermatophagoides mites (Acari: Pyroglyphidae) in dust samples collected in homes of allergic patients.

A medical service system for testing antigen levels of Dermatophagoides farinae Hughes and D. pteronyssinus (Trouessart) mites in house dust was established to allow physicians to monitor the environment of patients with allergies. Dust samples were collected from a 1-m2 area at different sites for 1 min using a commercial collection apparatus attached to a vacuum cleaner. Extracts from fine dust fractions were processed quantitatively for antigen by a sandwich enzyme-linked immunosorbent assay. Mean antigen levels contained in samples from carpets, tatamis, and futons ranged from 431 to 852 micrograms per unit weight of dust (g). When data were expressed as micrograms per m2, the mean antigen level obtained from carpets (41 micrograms/m2) was significantly higher than that obtained from tatamis (15 micrograms/m2) and futons (14 micrograms/m2). Comparison of 37 paired samples collected from 10 homes at an interval of 1 to 2 mo indicated that high antigen levels of > 50 micrograms/m2 at four sites (three carpets and one tatami) decreased sharply after improvement of hygienic conditions surrounding allergic patients.