Microwave irradiation as a novel strategy for mitigating airborne transmission of highly pathogenic avian influenza A(H5N1) virus: an optimization study

The highly pathogenic avian influenza A(H5N1) virus threatens animal and human health globally. Innovative strategies are needed to reduce airborne transmission and prevent outbreaks. This study investigated the efficacy of microwave inactivation against aerosolized A(H5N1) by (1) identifying the optimal frequency band in 10 min of exposure and (2) evaluating the effect of exposure time. A(H5N1) was aerosolized and exposed to various microwave frequencies (between 8 and 16 GHz with different ranges) for 10 minutes. Viral titers were quantified using TCID50, and inactivation was assessed by comparing irradiated samples to controls. The 11−13 GHz band resulted in the highest inactivation, with an average of 89% mean reduction in A(H5N1) titer in particular in the range of 11-12 GHZ (pick of efficacy). Considering the overall tests and results, the optimal band (8-12 GHZ) was further tested with 1, 3, and 5-minute exposures. Inactivation was time-dependent, with 5-minute exposure yielding a 94% mean reduction, compared to 58% and 48% for 3 and 1-minute exposures, respectively. Optimized microwave emitters in high-risk environments like poultry farms and veterinary clinics could offer a novel, non-chemical approach to mitigating avian influenza spread and outbreaks.