Wheeze in infancy: protection associated with yeasts in house dust contrasts with increased risk associated with yeasts in indoor air and other fungal taxa

Allergy. 2013 Nov;68(11):1410-8. doi: 10.1111/all.12254. Epub 2013 Oct 10.


Background: While fungal exposures are assumed to provoke wheeze through irritant or allergenic mechanisms, little is known about the differential effects of indoor and outdoor fungi on early-life wheeze.

Methods: In a Boston prospective birth cohort of 499 at-risk infants, culturable fungi in bedroom air and dust and outdoor air were measured at the age of 2-3 months. Wheeze was determined using bimonthly telephone questionnaires. Odds ratios were estimated for an interquartile increase in fungal natural log-transformed concentrations, adjusting for predictors of wheeze and potential confounders.

Results: Increased odds of 'any wheeze' (≥1 vs 0 episodes) by age one were positively associated with indoor dust Alternaria [odds ratio (OR) = 1.83; 95% confidence interval (CI), 1.07-3.14], Penicillium [OR = 1.18; (0.98-1.43)], and Cladosporium [OR = 1.47; (1.16-1.85)]; indoor air Penicillium [OR = 1.26; (0.92-1.74)]; and outdoor air Cladosporium [OR = 1.68; (1.04-2.72)]. In contrast, indoor dust yeasts were protective [OR = 0.78; (0.66-0.93)]. 'Frequent wheeze' (≥2 vs <2 episodes) by age one was borderline associated with dust yeasts [OR = 0.86; (0.70-1.04)] and indoor air yeasts [OR = 1.53; (0.93-2.53)]. Alternaria concentration was associated with any wheeze for children with maternal mold sensitization [OR = 9.16; (1.37-61.22)], but not for those without maternal mold sensitization [OR = 1.32; (0.79-2.20)].

Conclusions: While wheeze rates were higher with exposures to fungal taxa considered to be irritant or allergenic in sensitive subjects, yeasts in the home had a strong protective association with wheeze in infancy. Molecular microbiologic studies may elucidate specific components of innate microbiologic stimulants that lead to contrasting effects on wheeze development.

Keywords: asthma; fungi; housing; wheeze; yeast.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Air Pollution, Indoor / adverse effects*
  • Alternaria / immunology
  • Animals
  • Antigens, Fungal / administration & dosage
  • Antigens, Fungal / immunology*
  • Aspergillus / immunology
  • Blattellidae / immunology
  • Cladosporium / immunology
  • Dust / immunology*
  • Female
  • Humans
  • Infant
  • Penicillium / immunology
  • Predictive Value of Tests
  • Prospective Studies
  • Respiratory Hypersensitivity / diagnosis
  • Respiratory Hypersensitivity / immunology
  • Respiratory Hypersensitivity / microbiology
  • Respiratory Sounds / diagnosis
  • Respiratory Sounds / immunology*
  • Risk Assessment


  • Antigens, Fungal
  • Dust