Association Between Fungal Spore Exposure in Inner-City Schools and Asthma Morbidity

To evaluate the association of school-based fungal spore exposures on asthma symptom days in children with asthma.

Children 4–13 years of age with persistent asthma attending an elementary school in the Northeast US from 2008–2013, where environmental sampling was obtained. Children had to have physician diagnosed asthma with symptoms in the prior 12 months, daily controller medication usage, or unscheduled medical visits for asthma in the past year.

Children were recruited from participating schools and given a detailed questionnaire, allergy testing, spirometry and exhaled nitric oxide measurements. Follow-up surveys were collected at 3, 6, 9, and 12 months after the baseline assessments. Skin prick testing was performed with Aspergillus, Alternaria tenuis, Penicillium, and Cladosporium. Fungal air sampling was collected and analyzed. The primary outcome was asthma symptom days (ASD) per 2-week period. Secondary outcomes included number of missed school days for asthma, number of hospitalizations and unscheduled healthcare visits for asthma, number of days caregiver changed plans or nights they lost sleep due to child’s asthma, and lung function. Associations between ASD and total fungus collected, fungal groupings and individual fungi were analyzed.

381 students from 38 schools completed baseline screening and were enrolled, 280 meeting full requirements for inclusion. Most students were Black or Hispanic. 40% had incomes < $25 000 and 72% had annual household income <$45 000. 81% had a family history of asthma. Fungal spores were present in all 438 classroom samples. Cladosporium, Penicillium/Aspergillus and Alternaria were the most prevalent. When looking at individual fungi, exposure to Alternaria was significantly associated with ASD in students sensitized to Alternaria, but not in those not sensitized. Students who were sensitized and exposed to high levels had 3.2 more ASD per 2-week period. This is ∼6 more ASD per month and 50 more ASD per school year.

Children with asthma who are sensitized to Alternaria and exposed to high levels have significantly more asthma symptom days than those sensitized but not exposed.

Several studies have shown that home fungus exposure may be associated with development of or worsening of asthma, but few have looked at schools. This article’s findings are consistent with others in finding that Alternaria, but not other fungi studied, influences the number of ASDs.