Exposure to Mouse Allergen in US Homes Associated With Asthma Symptoms
Exposure to Mouse Allergen in US Homes Associated With Asthma Symptoms
Background: Most studies investigating the role of residential mouse allergen exposures in asthma have focused on inner-city populations.
Objective: We examined whether elevated mouse allergen levels were associated with occupants' asthma status in a nationally representative sample of U.S. households.
Methods: Data for this study were collected as part of the National Survey of Lead and Allergens in Housing. This cross-sectional study surveyed 831 housing units inhabited by 2,456 individuals in 75 different locations throughout the United States. The survey obtained information on demographics, household characteristics, and occupants' health status by questionnaire and environmental observations. We used a polyclonal immunoassay to assess concentrations of mouse urinary protein (MUP) in vacuumed dust collected from various indoor sites.
Results: Of the surveyed homes, 82% had detectable levels of MUP, and in 35% of the homes, MUP concentrations exceeded 1.6 μg/g, a level that has been associated with increased mouse allergen sensitization rates. Current asthma, defined as having doctor-diagnosed asthma and asthma symptoms in the preceding 12 months, was positively associated with increased MUP levels. The observed association was modified by atopic status ; in allergic individuals, elevated MUP levels (> 1.6 μg/g) increased the odds of having asthma symptoms [adjusted OR = 1.93 ; 95% confidence interval (CI) , 1.14–3.27], but we found no association in those who did not report allergies (adjusted OR = 0.69 ; 95% CI, 0.33–1.44).
Conclusions: In allergic asthma, residential mouse allergen exposure is an important risk factor for asthma morbidity.
Mouse allergen exposure is a well-recognized risk factor for allergic sensitization and asthma in occupational settings (Bush and Stave 2003; Phipatanakul 2002). More recently, it has also been identified as a factor that may contribute to asthma morbidity in nonoccupational populations. Exposure and sensitization to mouse allergen are common, particularly among asthmatic populations in inner cities (Phipatanakul et al. 2000a, 2000b). In the National Cooperative Inner-City Asthma Study (NCICAS), which was the first study to examine mouse allergen exposures in residential environments, mouse allergen was detectable in an extraordinarily high percentage of the homes (74–100%) (Phipatanakul et al. 2000a). Findings from previous studies suggest that sensitization rates to mouse allergen increase with increasing exposure levels, although the dose–response relationship may not be linear (Matsui et al. 2007). Reported sensitization rates have generally ranged from 7% to 18% (Matsui et al. 2005; Phipatanakul et al. 2000b, 2007), although even higher rates have been reported (up to 40%) among asthmatic children with high exposure levels (Matsui et al. 2007). Recent studies have also demonstrated that elevated mouse allergen levels are associated with asthma morbidity in inner-city children and adults, highlighting the importance of mouse allergen in this population (Chew et al. 2006; Matsui et al. 2006).
Although most studies that have been published have targeted inner-city populations (Chew et al. 2003, 2006; Matsui et al. 2005, 2006, 2007; Phipatanakul et al. 2000a, 2000b), mouse allergen exposure may not be restricted to urban populations that have disproportionately high asthma prevalence rates. Studies have shown that mouse allergen exposure and mouse sensitivity can be surprisingly widespread, even outside inner-city areas (Matsui et al. 2004; Phipatanakul et al. 2005). Yet the role of residential mouse allergen exposure in asthma remains poorly characterized among the general U.S. population because previous studies have focused mainly on selected populations (i.e., children, asthmatics, and urban residents).
The National Survey of Lead and Allergens in Housing (NSLAH) was the first population-based study to estimate mouse allergen levels and examine mouse allergen exposure in relation to asthma in a nationally representative sample of the U.S. households (Vojta et al. 2002). We have previously described the details of the exposure characteristics (Cohn et al. 2004). In this article, we report associations between mouse allergen exposures and asthma-related symptoms in the study population.
Abstract and Introduction
Abstract
Background: Most studies investigating the role of residential mouse allergen exposures in asthma have focused on inner-city populations.
Objective: We examined whether elevated mouse allergen levels were associated with occupants' asthma status in a nationally representative sample of U.S. households.
Methods: Data for this study were collected as part of the National Survey of Lead and Allergens in Housing. This cross-sectional study surveyed 831 housing units inhabited by 2,456 individuals in 75 different locations throughout the United States. The survey obtained information on demographics, household characteristics, and occupants' health status by questionnaire and environmental observations. We used a polyclonal immunoassay to assess concentrations of mouse urinary protein (MUP) in vacuumed dust collected from various indoor sites.
Results: Of the surveyed homes, 82% had detectable levels of MUP, and in 35% of the homes, MUP concentrations exceeded 1.6 μg/g, a level that has been associated with increased mouse allergen sensitization rates. Current asthma, defined as having doctor-diagnosed asthma and asthma symptoms in the preceding 12 months, was positively associated with increased MUP levels. The observed association was modified by atopic status ; in allergic individuals, elevated MUP levels (> 1.6 μg/g) increased the odds of having asthma symptoms [adjusted OR = 1.93 ; 95% confidence interval (CI) , 1.14–3.27], but we found no association in those who did not report allergies (adjusted OR = 0.69 ; 95% CI, 0.33–1.44).
Conclusions: In allergic asthma, residential mouse allergen exposure is an important risk factor for asthma morbidity.
Introduction
Mouse allergen exposure is a well-recognized risk factor for allergic sensitization and asthma in occupational settings (Bush and Stave 2003; Phipatanakul 2002). More recently, it has also been identified as a factor that may contribute to asthma morbidity in nonoccupational populations. Exposure and sensitization to mouse allergen are common, particularly among asthmatic populations in inner cities (Phipatanakul et al. 2000a, 2000b). In the National Cooperative Inner-City Asthma Study (NCICAS), which was the first study to examine mouse allergen exposures in residential environments, mouse allergen was detectable in an extraordinarily high percentage of the homes (74–100%) (Phipatanakul et al. 2000a). Findings from previous studies suggest that sensitization rates to mouse allergen increase with increasing exposure levels, although the dose–response relationship may not be linear (Matsui et al. 2007). Reported sensitization rates have generally ranged from 7% to 18% (Matsui et al. 2005; Phipatanakul et al. 2000b, 2007), although even higher rates have been reported (up to 40%) among asthmatic children with high exposure levels (Matsui et al. 2007). Recent studies have also demonstrated that elevated mouse allergen levels are associated with asthma morbidity in inner-city children and adults, highlighting the importance of mouse allergen in this population (Chew et al. 2006; Matsui et al. 2006).
Although most studies that have been published have targeted inner-city populations (Chew et al. 2003, 2006; Matsui et al. 2005, 2006, 2007; Phipatanakul et al. 2000a, 2000b), mouse allergen exposure may not be restricted to urban populations that have disproportionately high asthma prevalence rates. Studies have shown that mouse allergen exposure and mouse sensitivity can be surprisingly widespread, even outside inner-city areas (Matsui et al. 2004; Phipatanakul et al. 2005). Yet the role of residential mouse allergen exposure in asthma remains poorly characterized among the general U.S. population because previous studies have focused mainly on selected populations (i.e., children, asthmatics, and urban residents).
The National Survey of Lead and Allergens in Housing (NSLAH) was the first population-based study to estimate mouse allergen levels and examine mouse allergen exposure in relation to asthma in a nationally representative sample of the U.S. households (Vojta et al. 2002). We have previously described the details of the exposure characteristics (Cohn et al. 2004). In this article, we report associations between mouse allergen exposures and asthma-related symptoms in the study population.
