Distribution and abundance of house dust mites, Dermatophagoides spp., in different ecological localities in Esna City, Kena Governorate, Egypt.

The distribution and abundance of house dust mites, Dermatophagoides spp. were studied in July, September and November, 1995 in three different localities in Esna City, Kena Governorate, Upper Egypt. During these months, 15 houses were sampled in each locality. 87% of riverside houses were infested with mites where D. pteronyssinus dominated (80%) over D. farinae. Sixty percent of the valley houses sampled were infested, where D. farinae was dominant (66%). Densities of both Dermatophagoides spp., were considerably higher in riverside than in valley houses. Live mites were not found in the lightly infested houses sampled in the desert area (54% positive). Relative humidity, which varied in houses located in different climatic localities in Esna City, was noted to be the principal limiting factor influencing the distribution and abundance of both species. Temperature did not appear to be an important factor influencing the distribution and abundance.