House dust mite population in the bedrooms of people with dust mite allergy in the city of Ordu, Turkey

House dust mites are a major source of allergens that are responsible for allergic symptoms such as asthma and atopic diseases. The warm and humid climate of Ordu, which is situated on the Black Sea coast of Turkey is highly suitable for the growth of house dust mites. Seasonal changes in the populations of the house dust mites were studied in five houses of dust-mite sensitive people with asthma between 2013 and 2015. Dust samples were obtained once a month to assess the monthly distribution of dust mites. House dust mites were isolated from samples by a wet-sieving method. Permanent slides were prepared for morphologically based species determination. The most abundant species were Dermatophagoides pteronyssinus (Trouessart, 1897) and Dermatophagoides farinae (Hughes, 1961) (Astigmata: Pyroglyphidae), 65.4 and 31.0% of the total count of mites, respectively. Dust mites can survive all year round and are widely distributed in different types of houses in the city of Ordu. The mite abundance reached its peak in all houses during August (26-28 degrees C and 64-78% RH). The discomfort for people who have a dust mite allergy may reach a peak specifically during this time and they need to take extra precautions to reduce exposure to dust mites as much as possible during this period.