House dust mite ; Seasonal distribution ; Allergen
Abstract
Background: Exposure to aeroallergens is a critical factor for sensitization of allergens and provocation of respiratory allergic symptoms.
Objective: We investigated the seasonal variation of the infestation of house dust mites in the domestic environment of Seoul and its vicinities and its influences on the health of inhabitants. Method: The study was performed from April 2000 through January 2001, comprised 63 houses. The dust samples were collected from bedclothes, bedroom, kitchen, and living room floors by vacuum cleaner in April, July, October, and January. Group 1 major allergen of D. farinae (Der f 1) was measured by two-site ELISA. Specific IgE of enrolled subjects was measured by ELISA. The status of health was evaluated by the questionnaire comprising 5 domains and 26 items.
Result: House dust mite (HDM) was detected in 85% houses. Concentration of Der f 1 in the bedclothes dust was highest in October, followed by January, July, and April. The seasonal variation of Der f 1 was prominent in the floor dust. The prevalence of specific IgE to HDM is higher in subjects with high Der f 1 in bedclothes dust (>2μg/g dust). There was no difference in eye and nasal symptoms between inhabitants with low (Der f 1<2μg/g dust) and high Der f 1 (Der f 1≥2μg/g dust) group in bedclothes dust. However, in the high Der f 1 group, inhabitants more frequently had complained of the difficulty in breathing at day and night during recent 1 year.
Conclusion: Marked seasonal variation of HDM infestation is found in domestic environments of Seoul citizens and exposure to HDM can affect the health of the inhabitants.