Objective: To determine airborne-fungi contamination in herbal inhalers, potentially causing opportunistic fungal infection.

Material and Method: A cross-sectional study determined airborne-fungi contaminated in 45 samples of sealed, newly-opened herbal inhalers distributed in Samutprakarn province, Thailand. Phenotypic and genotypic characteristics of fungi isolated from the inhalers were determined by PCR and DNA sequencing.

Results: Of 45 samples, 33 were positive for contaminant fungi (73.3%). The fungi can be divided into 2 groups;opportunistic fungi and contaminant fungi. The opportunistic fungi were Aspergillus sydowii, Aspergillus aculeatus, Aspergillus calidoustus, Cladosporium cladosporioides,Cladosporium spp., Penicillium citrinum, Bipolaris papendorfii, Clavispora lusitaniae and Candida orthopsilosis, whereas contaminant fungi were Emericella variecolor, Neurospora intermedia, Trametes polyzona and Glomerella graminicola. Prevalence of the opportunistic fungi isolated from different product ingredients was 100%, 83.3% and 40%, from products with air-dried herbs, air-dried herbs mixed with fragrant oil and finger citron, respectively.

Conclusion: Contaminant fungi have been isolated from several herbal inhaler samples. Importantly, the most common opportunistic fungi, Aspergillus spp. were found in the studied samples. In order to decrease the risk of unexpected fungal infection through inhaling fungal spores from herbal inhalers, the Food and Drug Administration should investigate and qualify a production control of manufacturers.