Spatial and temporal distribution of house dust mite (Astigmata: Pyroglyphidae) allergens Der p 1 and Der f 1 in Barbadian homes

House features contribute to house dust mite abundance and, therefore, exposure to mite allergens. Our study assessed the hypothesis that modernization of the domestic environment in a tropical setting may lead to a level of allergen from the house dust mites Dermatophagoides pteronyssinus (Trouessart) and D. farinae Hughes that previously has been defined clinically as at risk for people who suffer from allergic disease. Allergen (Der p 1 and Der f 1) levels were measured at 4 sites (mattress, bedroom floor, living room floor, and furniture) in 17 houses in Barbados during dry and rainy seasons. Der p 1 (17 of 17 homes) at all 4 sites did not vary significantly from the dry to rainy season. Allergen levels varied according to site, and were highest in living room furniture in both seasons (geometric mean 40.37 and 64.17 micrograms/g, respectively). Concentration of Der p 1 allergens were higher in concrete than in wood or mixed concrete and wood houses. Der f 1 (9 of 17 homes) levels were lower than Der p 1 by 1/1,000 (both seasons). Results indicate that season is less important in regard to levels of Der p 1 than house construction and confirm other studies that implicate D. pteronyssinus as a more abundant source of allergen than D. farinae in this tropical setting