Mouse allergen. I. The prevalence of mouse allergen in inner-city homes

Background: Although mouse allergen is a well-defined cause of IgE-mediated hypersensitivity in occupational settings, it has not been well studied in the general population. Objective: We sought to determine the prevalence of mouse allergen in inner-city homes. Methods: A subset of 608 homes from the National Cooperative Inner-City Asthma Study population had dust samples adequate for analysis of mouse allergen. In addition, data regarding the demographics and housing of the subjects were related to the mouse allergen levels. Results: Ninety-five percent of all homes had detectable mouse allergen (Mus m 1) in at least one room, with the highest levels found in kitchens (kitchen: range, 0-618 μg/g; median, 1.60 μg/g; bedroom: range, 0-294 μg/g; median, 0.52 μg/g; television-living room: range, 0-203 μg/g; median, 0.57 μg/g). By city, 100% of the kitchens in Baltimore had detectable mouse allergen, with the lowest percentage (74%) in Cleveland. Mouse allergen levels correlated among rooms (R = 0.65-0.75). Forty-nine percent of the homes had reported problems with mice within the last year, and 29% of the homes had evidence of mice in one or more rooms on home inspection and had higher levels of mouse allergen (P =. 0001). Higher allergen levels were also associated with evidence of cockroach infestation in any room (P =. 006). None of the other subject or housing demographics evaluated were associated with a higher prevalence or level of mouse allergen. Conclusions: We conclude that mouse allergen is widely distributed in inner-city homes and that cockroach infestation is associated with high mouse allergen levels.