A Method to Evaluate and Eliminate Fungal Contamination in Household Air Conditioners

Background. Allergic fungal airway diseases, such as asthma and allergic bronchopulmonary mycosis (ABPM), are often difficult to manage with medical treatment alone; therefore, environmental exposure should be accurately evaluated minimized. In the present study, we established a method evaluate eliminate contamination in household air conditioners (ACs). Methods. fall of 2020, an survey living rooms was conducted 17 Japanese residences patients ABPM or related diseases. Household ductless minisplit AC units were disassembled collect swab samples from internal parts (filter, heat exchanger, blower fan, vent), followed by high-pressure washing. Fungal abundance composition cleaning effluents ACs well house dust determined using quantitative PCR next-generation sequencing transcribed spacer 1 region, respectively. A weighted UniFrac distance calculated analyze similarity mycobiome among samples. Results. All interior contained high levels DNA, fans being most contaminated parts. Cladosporium Toxicocladosporium, Aureobasidium, Aspergillus, Rhodotorula, common fungi detected unit. High-pressure washing decreased over 99% all strongly correlated those effluents. Conclusion. Interior downstream exchangers major sites contamination, possibly polluting indoor residences. is highly effective for decontamination.