National prevalence and exposure risk for cockroach allergen in U.S. households

Abstract

We characterized the prevalence of cockroach allergen exposure in a nationally representative sample of U.S. homes and assessed risk factors for elevated concentrations.

Design: We used data from the National Survey of Lead and Allergens in Housing, a population-based cross-sectional survey.

Participants: Participants were residents of 831 U.S. homes in the survey.

Evaluations/measurements: We analyzed allergen, questionnaire, and observational data of 831 U.S. homes.

Results: Cockroach allergen (Bla g 1) concentrations exceed 2.0 U/g, a level associated with allergic sensitization, in 11% of U.S. living room floors and 13% of kitchen floors. Concentrations exceed 8.0 U/g, a level associated with asthma morbidity, in 3% of living room floors and 10% of kitchen floors. Elevated concentrations were observed in high-rise apartments, urban settings, pre-1940 constructions, and households with incomes < $20,000. Odds of having concentrations > 8.0 U/g were greatest when roach problems were reported or observed and increased with the number of cockroaches observed and with indications of recent cockroach activity.

Conclusions: Household cockroach allergen exposure is characterized in a nationally representative context. The allergen is prevalent in many settings, at levels that may contribute to allergic sensitization and asthma morbidity.

Relevance to clinical or professional practice: Likelihood of exposure can be assessed by consideration of demographic and household determinants.