Dermatophagoides pteronyssinus in ambient air bioaerosols

Background: being the primary allergenic species typically associated with indoor environments. Even effective multicomponent interventions creating an HDM-free indoor environment are often insufficient to prevent allergy, as HDM exposure may also occur outdoors. Objective: To assess the potential for outdoor HDM exposure, we applied air biomass sequencing and metagenomic techniques to detect HDM DNA in both indoor and outdoor bioaerosols, offering an alternative to conventional dust sampling methods. Methods: We used 2 data sets in this study: (1) a global data set comprising 1,171 outdoor air samples collected across 33 countries in open air environments and (2) a data set of indoor (n = 161) and outdoor (n = 156) air samples collected across 156 apartments from 106 locations in Singapore. All air samples were collected by drawing 24,000 to 36,000 L of air using SASS3100 air samplers; all samples were processed identically. Species-level taxonomic classification was performed using Kaiju software aligned to the National Center for Biotechnology Information nonredundant database, with a minimum threshold of 40 reads per taxon. Results: were also detected in Singapore, albeit at lower frequencies. Conclusion: Our findings highlight the need to expand environmental allergen surveillance beyond household dust to include ambient and outdoor air, particularly in tropical climates.