Fungal diversity in homes and asthma morbidity among school-age children in New York City. Neighborhood Asthma and Allergy Study

Asthma development has been inversely associated with exposure to fungal diversity. However, the influence of fungi on measures of asthma morbidity is not well understood. This study aimed to test the hypothesis that fungal diversity is inversely associated with neighborhood asthma prevalence and identify specific fungal species associated with asthma morbidity. Children aged 7-8 years (n=347) living in higher (11-18%) and lower (3-9%) asthma prevalence neighborhoods were recruited within an asthma case-control study. Fungal communities were analyzed from floor dust using high-throughput DNA sequencing. A subset of asthmatic children (n=144) was followed to age 10-11 to determine asthma persistence. Neighborhood asthma prevalence was inversely associated with fungal species richness (P=0.005) and Shannon diversity (P=0.01). Associations between neighborhood asthma prevalence and diversity indices were driven by differences in building type and presence of bedroom carpet. Among children with asthma at age 7-8 years, Shannon diversity was inversely associated with frequent asthma symptoms at that age (OR 0.72, P=0.017) and richness was inversely associated with asthma persistence to age 10-11 (OR 0.99, P=0.040). Analyses of individual fungal species did not show significant associations with asthma outcomes when adjusted for false discovery rates. Lower fungal diversity was associated with asthma symptoms in this urban setting. Individual fungal species associated with asthma morbidity were not detected. Further research is warranted into building type, carpeting, and other environmental characteristics which influence fungal exposures in homes. [This sequencing data was also used to examine the effects of season, relative humidity, and temperature on indoor fungal concentrations]

哮喘的发生与真菌多样性暴露呈负相关。然而，真菌对哮喘发病相关指标的影响尚不明确。本研究旨在验证「真菌多样性与社区哮喘患病率呈负相关」这一假说，并筛选出与哮喘发病相关的特定真菌物种。本研究在一项哮喘病例对照研究（case-control study）中，招募了居住于哮喘患病率较高（11%~18%）与较低（3%~9%）社区的7~8岁儿童共347例（n=347）。研究人员通过高通量DNA测序（high-throughput DNA sequencing）对地板灰尘中的真菌群落进行分析。对其中144名哮喘儿童进行随访至10~11岁，以明确哮喘的持续情况。结果显示，社区哮喘患病率与真菌物种丰富度（P=0.005）及香农多样性（Shannon diversity，P=0.01）呈负相关。社区哮喘患病率与多样性指数之间的关联，受建筑类型及卧室地毯铺设情况的差异影响。在7~8岁时确诊哮喘的儿童亚组中，香农多样性与该年龄段的频繁哮喘症状呈负相关（优势比OR=0.72，P=0.017），而物种丰富度与哮喘持续至10~11岁呈负相关（OR=0.99，P=0.040）。对单个真菌物种的分析经假发现率（false discovery rates）校正后，未发现其与哮喘转归存在显著关联。在本次城市人群研究中，较低的真菌多样性与哮喘症状相关，且未检测到与哮喘发病相关的单一真菌物种。有必要针对建筑类型、地毯铺设及其他影响家庭真菌暴露的环境特征开展进一步研究。[本测序数据还被用于分析季节、相对湿度及温度对室内真菌浓度的影响]