engleski

Environmental exposure and sensitization to dust mites in Croatia

Background: The rewiev of epidemiological studies related to environmental exposure and allergy to pyroglyphid ("house dust mites") and non-pyroglyphid ("storage mites") mites in Croatia. Subjects: Studies were performed on adult urban and rural general population from continental and Mediterranean region of Croatia, and on several industrial populations from continental region which were occupationally exposed to various organic dusts (textile, paper-mill, meat processing, brewery, animal food workers and swine farmers). Material: House dust samples were collected from the floors of bedrooms and living rooms in the urban and rural continental, Mediterranean areas of Croatia, and from the paper-recycling plant. Methods: The mites were separated from the dust using the floatation method and then microscopically identified. The levels of Der p 1, Der f 1 and Der 2 were measured using the DUSTSCREENTM test (Heska AG, Switzerland). Allergy to house dust mites (HDM) Dermatophagoides pteronyssinus (DP) and Dermatophagoides farinae (DF), and storage mites (SM) Lepidoglyphus destructor (LD) and Tyrophagus putrescentiae (TP) was established by standard questionnaire, skin prick testing (SPT) and serum specific IgE measurement by ELISA method. Results: The prevalence of allergy to HDM in general urban population of continental region was 13% in year 1995, and raised to 22.4% in year 2000., when was established also 14.9% subjects with allergy to Lepidoglyphus destructor and 22.3% to Tyrophagus putrescentiae. The significantly higher frequency of allergy to HDM in meat processing, animal food, textile workers and swine farmers then in general population of the same region was established. The frequency of allergy to SM was significantly higher in paper-mill workers then in group of postmen from the same region. High frequencies of allergy to SM in our studies, particularly to T.putrescentiae, led as to data analysis which confirmed the insufficient specificity of T.putrescentiae allergen extract used for skin prick testing. In 2002., acarological analysis of dust samples were introduced. More then 70% of mites identified in all areas were pyroglyphid. Non-pyroglyphid mites participated with 20-25% of all identified mites in the Mediterranean area (Blomia, Lepidoglyphus and Glycyphagus) and with 15% in the continental area (Lepidoglyphus and Acarus). T.putrescentiae was found only sporadically in both regions. The highest Der p 1 median levels were found in the Mediterranean area, with significantly lower levels in the continental rural and urban areas (4.5; 2; 0.85 mcg/g of dust; P=0.0001). The highest Der f 1 median levels were found in the continental urban area, with significantly lower levels in the continental rural and Mediterranean area (0.88; 0.75; 0 mcg/g of dust; P=0.0013). The levels of Der f 1 were significantly higher in samples taken from households with central heating than from those with traditional heating (1: 0.25 mcg/g of dust; P<0.01). In industrial dust sample from paper-recycling plant, Der p 1 and Der f 1 level were below 0,5 mcg/g and no dust mites were found microscopically. Conclusions: The prevalence of allergy to HDM in general urban population of continental region of Croatia is around 20% with significant environmental exposure to HDM in general indoor conditions. The high frequency of allergy to HDM in some industrial populations is most likely the reflection of such exposure in general conditions. High frequency of allergy to SM in general and working urban populations is probably due to cross-reactivity between HDM and SM and the non-specific skin reactions, particularly to T.putrescentiae. The results of acarologic analysis encourage the implementation of separate diagnostic dust mite lists for the continental and Mediterranean regions of Croatia. Compared to traditional heating, central heating significantly increases the risk of exposure to Der f 1 levels >2 mcg/g of dust which are levels at risk for developing allergy to DF.

dust mites; dust samples; Der p 1; Der f 1; storage mites

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