[Control of house dust mites and mite allergens by special mite-preventive futon]

We studied the effect of a recently-developed special mite-preventive futon (bedding) on mite population and mite allergen contents (Der I and Der II) in asthmatic children and their families (23 sets) for 2 years. 1. The number of mites (vacuumed samples) in the 124 sets of futon for 2 years was 6.4 (SD +/- 8.8) in average in the mite-preventive futon which was significantly smaller than the number (about 1/10) in the control futon: 70.0 (SD +/- 99) (p less than 0.001). 2. Follow-up studies were made on the mite population about 2 years (3, 6, 9 12 and 27 months afterwards). The numbers of mites in all the mite-preventive futon was always 1/10 or less than that of in the control futon (p less than 0.01). 3. The mite allergens (Der I and Der II) were measured in the cotton stuffing of the futon used for 2 years. The mite allergen counts in the mite-preventive futon averaged about 1/24 of those in the control futon. 4. Airborne mite allergens (Der I and Der II) obtained by beating the futon were measured. The ratio of the mite allergen count in the mite-preventive futon to the control futon was found to be 1:22-264. These results indicate that the special mite-preventive futon always inhibit mite infestation at least 1/10 of that in the ordinary (control) futon and that the count of mite allergens in the cotton stuffing and in the airborne particles was even lower in the mite-preventive futon.