Dysbiosis in the Nasal Mycobiome of Infants Born in the Aftermath of Hurricane Maria

Hurricanes and flooding events substantially elevate indoor fungal spore levels, which have been associated with increased risks of developing childhood asthma and other adverse respiratory outcomes. Although environmental fungal compositions following major hurricanes have been well characterized, the fungal communities within the nasal cavity (i.e., the nasal mycobiome) of exposed individuals remain unexplored. We collected nasal swab samples from infants following Hurricane Maria in San Juan, Puerto Rico, during two periods (March to August 2018 and February to September 2019). We processed a total of 58 samples (26 from the first year and 32 from the second year post-Hurricane Maria) and performed internally transcribed spacer (ITS) rRNA gene sequencing to characterize and compare the infant nasal mycobiome between the two groups. Although alpha-diversity did not differ significantly, beta-diversity analyses revealed significantly different fungal compositions between the two groups (p < 0.01). Infants exposed during the first year post-Hurricane Maria had significantly higher abundances of Alternaria, Eutypella, Schizophyllum, and Auricularia, compared to infants from the second year. Alternaria was also more prevalent in the first-year than in the second-year infants (42% vs. 9%, p = 0.01). Our study provides evidence linking early-life hurricane exposures to elevated risks of developing childhood asthma.