THE PREVALENCE OF DERMATOPHAGOIDES MITE ALLERGEN IN COLORADO HOMES UTILIZING CENTRAL EVAPORATIVE COOLERS

Objective: The prevalence of mite allergen was studied in homes in whi ch the indoor relative humidity may be increased by use of an evaporat ive cooler. Methods: Colorado homes in which central evaporative coole rs are used and control homes were evaluated. ELISAs with monoclonal a ntibodies specific for Der p 1 and Der f 1 were performed on dust samp les from each home in May and August. Indoor relative humidity and tem peratures were recorded daily. Results: May samples did not show signi ficant levels of mite allergen (<2 mu g/gm dust). Of the August sample s, 48 of 95 samples from homes with evaporative coolers (50.5%) had le vels of Der p 1 and Der f 1 of 2 mu g/gm dust or greater, but only 5 o f 95 control samples (5.2%) had levels of 2 mu g/gm dust or greater (p < 0.00001). Twelve of 19 homes with evaporative coolers (63%) were po sitive for mite allergen. Five of 19 (26%) control homes were positive (p < 0.05). The homes with evaporative coolers had average indoor rel ative humidity of 51% or greater: control homes had average relative h umidity of less than 45%.Conclusion: Altering the indoor environment b y raising indoor relative humidity through use of evaporative coolers lends to conditions that may facilitate Dermatophagoides survival.