ABSTRACT
Coccidioidomycosis is an emerging fungal infection caused by inhalation of Coccidioides spp. spores. While airborne dispersal is critical to Coccidioides transmission, limited recovery of the pathogen from air has hindered understanding of the aerosolization and transport of spores. Here, we examine uncrewed aircraft systems (UAS) with portable, active air samplers as a novel means of capturing aerosolized Coccidioides and characterizing emissions and exposure risk. We sampled in September 2023 in eastern San Luis Obispo County, California, in an area with confirmed Coccidioides immitis in soils. We completed 41 20-minute flights across 14 sites using UAS equipped with an 8 L/min bioaerosol sampler and a low-cost particulate matter sensor. We sampled source soils and air under ambient conditions using one UAS at 1-10 m above ground level, and under a simulated high-dust event using two UAS, one at <2 m height and one at 5-12 m. We detected Coccidioides DNA in two of 41 air samples (4.9%), both under ambient conditions at 8 m above ground level, representing the highest known height of airborne Coccidioides detection. Spatially explicit UAS-based sampling could enhance understanding of Coccidioides aerobiology and enable detection in hard-to-reach or hazardous air masses, including dust storms and wildfire smoke.
Synopsis UAS-based air sampling for bioaerosols, including pathogenic Coccidioides spp., opens new possibilities for characterizing the aerosolization and transport of fungal spores and other airborne pathogens.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
Methods revised for clarity, other sections revised for clarity and brevity, and Acknowledgements updated.