Association between fungal spore exposure in inner-city schools and asthma morbidity

Abstract Background Home fungus exposures may be associated with development or worsening of asthma. Little is known about the effects of school/classroom fungus exposures on asthma morbidity in students. Objective To evaluate the association of school-based fungus exposures on asthma symptoms in both fungus-sensitized and nonsensitized students with asthma. Methods In this prospective study, 280 children with asthma from 37 inner-city schools were phenotypically characterized at baseline and followed-up for 1 year. Fungal spores were collected by using a Burkard air sampler twice during the school year. Clinical outcomes were evaluated throughout the school year and linked to classroom-specific airborne spore sampling. The primary outcome was days with asthma symptoms per 2-week period. Results Fungal spores were present in all classroom samples. The geometric mean of the total fungi was 316.9 spores/m3 and ranged from 15.0 to 59,345.7 spores/m3. There was variability in total fungus quantity between schools and classrooms within the same school. Mitospores were the most commonly detected fungal grouping. Investigation of the individual mitospores revealed that exposure to Alternaria was significantly associated with asthma symptom days in students sensitized to Alternaria (OR = 3.61, CI = 1.34-9.76, P = .01), but not in children not sensitized to Alternaria (OR = 1.04, CI = 0.72-1.49, P = .85). Students sensitized to Alternaria and exposed to high levels (≥75th percentile exposure) had 3.2 more symptom days per 2-week period as compared with students sensitized but exposed to lower levels. Conclusion Children with asthma who are sensitized to Alternaria and exposed to this fungus in their classroom may have significantly more days with asthma symptoms than those who were sensitized and not exposed. Clinical Trial Registration: Clinicaltrials.gov NCT01756391 .