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The study of house dust mites in Taiwan
1Department of Pediatrics, National Taiwan University College of Medicine, Taipei, Republic of China.
Abstract:
By using a radioallergosorbent test (RAST) and intradermal skin testing, our previous studies strongly suggested that house dust mites are the most important allergen in Taiwan, especially in asthmatic children. This study was conducted to determine the distribution of house dust mites in houses of mite-sensitive asthmatic children and normals, the species of mites in various house dust samples, the seasonal prevalence, and the relation between the content of mite allergen and the mite density in dusts. Serial samples were collected every month between February 1986 and January 1987 from 61 houses of mite-allergic patients and nine normals. About 1 m2 surface area each of (A) family couch, (B) TV room floor carpet, (C) mattress, and (D) bed room floor carpet was vacuumed for one minute. The flotation method was used to collect mites in dusts and mites were counted under an inverted phase contrast microscope. Identification of house dust mite species was also performed. The RAST inhibition method was used for assay of mite allergen in dust extracts. The results showed the following six points. (1) Dermatophagoides pteronyssinus (DP) was the dominant species found in house dust in the Taipei area (78.8%). (2) The mean number of mites was greater in August through November and lowest in July. (3) The content of mite allergen did not correlate with the number of mites in dust sample. (4) The average number of mites in patients' houses was not different from that in normals' houses.(ABSTRACT TRUNCATED AT 250 WORDS)
Insights
House dust mites, particularly Dermatophagoides pteronyssinus, are prevalent in Taiwanese homes. Mite allergen levels did not correlate with mite density, suggesting complex allergen exposure dynamics for asthmatic children.
Area of Science:
- Allergy and Immunology
- Environmental Health
- Entomology
Background:
- Previous studies identified house dust mites as significant allergens in Taiwan, especially for pediatric asthma.
- Understanding mite distribution and allergen levels is crucial for managing allergic respiratory diseases.
Purpose of the Study:
- To investigate house dust mite distribution and species in homes of mite-sensitive asthmatics and controls.
- To determine seasonal mite prevalence and the relationship between mite allergen content and mite density.
- To identify the dominant house dust mite species in the Taipei area.
Main Methods:
- Monthly dust samples collected from couches, carpets, and mattresses in 61 asthmatic and 9 control households.
- Mite enumeration using the flotation method and microscopic counting.
- Species identification and mite allergen quantification via RAST inhibition.
Main Results:
- Dermatophagoides pteronyssinus was the predominant species (78.8%) in Taipei dust samples.
- Mite populations peaked from August to November and were lowest in July.
- No significant correlation was found between mite allergen levels and mite density; mite counts were similar in patient and control homes.
Conclusions:
- Dermatophagoides pteronyssinus is the primary house dust mite allergen in Taiwan.
- Seasonal variations in mite density occur, but allergen levels are not directly proportional to mite counts.
- Mite allergen exposure may be complex, independent of simple mite density, impacting asthma management strategies.