Novel use of far UV-C light as a surface disinfectant in the poultry industry: trials on broiler farms show reduced bacterial burden in poultry anterooms and on wellington boots

Abstract Far ultraviolet-C (UV-C) irradiation at 222 nm has widely been shown to deactivate bacteria, viruses and fungi in in-vitro experiments. However, there are few studies testing the technology on real life surface. There are no peer reviewed studies on the efficacy and feasibility of far UV-C disinfection in real-life agricultural settings. The aim of this study was to investigate whether far UV-C irradiation installations on UK broiler poultry farms could reduce bacterial surface burden. On two farms one pair of wellington boots was submitted to far UV-C irradiation at 222 nm after staff exiting the bird housing, using a purpose build disinfection box. Swabs ( n = 780) were taken from the bottom side of the soles before and after irradiation and from a pair of non-irradiated control boots. In a separate trial wall mounted Far UV-C systems were installed in a poultry anteroom and vestibule. Swabs ( n = 615) were taken from irradiated and non-irradiated (control) anteroom floors divided into 4 zones (L1-4), vestibule floors divided into 2 zones (V1, V2) and walls divided into 2 zones (VW1, VW2) and the door handle (VD) leading to bird housing. For both studies surface swabs were taken twice a week during the first 4–5 weeks of a bird crop. This was repeated over 3–4 and 4–5 crops for the wellington trial and the poultry anteroom trial respectively. Swabs were plated in the laboratory and the number colony forming units (cfu’s) were determined. Overall, there was a significant cfu reduction between treatments ( p < 0.001), after wellington boot exposure to far UV-C irradiation compared to pre-exposure cfu counts and cfu’s on control boots. Despite some technical challenges, across most anteroom and vestibule sampling locations, cfu’s from swabs taken from far UV-C irradiated areas were significantly lower than cfu’s from control area swabs. Far UV-C irradiation in livestock settings could be a promising added biosecurity layer on broiler farms and could be applicable to a range of livestock systems. Further research and development is required in areas such as installation adaptations to farms systems and settings, feasibility of implementation and cost benefit analyses.