SEASONAL FLUCTUATIONS OF DERMATOPHAGOIDES MITE POPULATION IN-HOUSE DUST

To evaluate seasonal fluctuations of Dermatophagoides species (sp.) in residential houses in Mie Prefecture, Japan, we employed the ELISA in hibition method with rabbit polyclonal antibody to eggs and adult mite s. House dust accumulated for seven days in vacuum cleaners was collec ted from 14 houses of atopic patients every month for one year. The on e-week-dust samples weighed from 2.5 to 117 g (mean 35.9 g). The densi ty of Dermatophagoides spp. in the dust samples were 5 to 755 mites pe r gram (mean 109). During one week, 100 to 20,400 (mean 4,200) mites o f Dermatophagoides sp. were collected. Among 142 samples in one year, 50 (35.2%) contained more than 100 mites per gram, which is a critical number for atopic symptoms. From December to February, 12 (34.5%) out of 35 samples contained more than 100 mites per gram. These results s uggest that Dermatophagoides sp. have become a year-round allergen in Japan.