Cat allergen (Fel d 1) levels on school children's clothing and in primary school classrooms in Wellington, New Zealand.

Abstract

New Zealand has a high prevalence of the major allergic diseases including asthma, rhinitis, and eczema, and cat ownership is common, with more than 50% of homes containing a cat. The study was designed to examine the levels of cat allergen (Fel d 1) in the primary school environment, both on floors and on children's clothing. We collected and analyzed dust samples from 11 school classrooms and from 202 children's garments using vacuum sampling and two-site monoclonal antibody ELISA, respectively. Environmental variables were identified by questionnaire. The geometric mean level of Fel d 1 in classrooms was 2.61 micro/gm (95% confidence interval, 1.28 to 3.84); however, seven classrooms had a floor sample with Fel d 1 greater than 8 microg/m2. Carpeted floor levels at 2.21 microg/gm (1.28 to 3.84) were considerably higher than those on uncarpeted floors, at 0.33 microg/gm (0.1 to 1.14). Floor levels and pupil cat ownership rates were positively correlated (r2 = 0.93, p = 0.0003). Children from homes with cats carried allergen on their clothes (mean Fel d 1, 6.10 microg per garment compared with non-cat owners (0.72 microg per garment). Wool and polyester garments contained more Fel d 1 than cotton clothing. Girls' clothing had significantly higher levels of allergen than did that of boys, even after controlling for cat status and fabric differences. Carpeting should be discouraged in environments such as schools and child care centers, where children spend considerable time. Transport of Fel d 1 on clothing from the domestic to the school environment is a major source of classroom cat allergen.