Evaluation of Far Ultraviolet-C Light for Decontamination of Organisms in Whole Milk and Chicken Manure

Background: The dissemination of highly pathogenic avian influenza (HPAI) A(H5N1) in US poultry and dairy cows poses a public health threat. Farm workers caring for infected animals are at risk to acquire infections due to exposure to contaminated milk or poultry feces and secretions. Far ultraviol...

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Main Authors: Samir Memic, Jennifer Cadnum, Curtis Donskey
Format: Article
Language:English
Published: Case Western Reserve University 2025-05-01
Series:Pathogens and Immunity
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Online Access:https://www.paijournal.com/index.php/paijournal/article/view/801
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author Samir Memic
Jennifer Cadnum
Curtis Donskey
author_facet Samir Memic
Jennifer Cadnum
Curtis Donskey
author_sort Samir Memic
collection DOAJ
description Background: The dissemination of highly pathogenic avian influenza (HPAI) A(H5N1) in US poultry and dairy cows poses a public health threat. Farm workers caring for infected animals are at risk to acquire infections due to exposure to contaminated milk or poultry feces and secretions. Far ultraviolet-C (UV-C) light could provide continuous decontamination of surfaces and air in agricultural settings, but efficacy against organisms in whole milk or chicken manure is unclear. Methods: We examined the efficacy of far UV-C light against bacteriophage MS2 and methicillin-resistant Staphylococcus aureus (MRSA) in phosphate-buffered saline (PBS), 5% fetal calf serum, whole milk, or 5%, 10%, and 25% chicken manure, both in liquid suspension and dried on surfaces. We also compared the efficacy of 300 mJ/cm2 doses of far UV-C and 254-nm UV-C light against the test organisms in liquid droplets or droplets dried on surfaces.  Results: For both test organisms, far UV-C achieved significantly smaller log10 reductions in whole milk and in chicken manure suspensions than in PBS or 5% fetal calf serum, both in liquid suspension and when dried on surfaces (P<0.0001). In whole milk, average reductions of both organisms with all doses were <1.2 log10 in liquid suspensions and <2.4 log10 when dried on surfaces. We found 254-nm UV-C was significantly more effective in reducing MRSA and MS2 dried on surfaces in whole milk or in 10% chicken manure (P<0.02) but not in liquid droplets (P>0.05) except 5% chicken manure (P<0.001).  Conclusions: Our results suggest that in the absence of prior cleaning and disinfection far UV-C and 254-nm UV-C light technologies may have limited efficacy as an adjunctive method to reduce the risk for transmission of HPAI from surfaces in high-risk settings on farms.
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spelling doaj-art-048160fd737f4319bd95395beea3e01c2025-08-20T01:52:12ZengCase Western Reserve UniversityPathogens and Immunity2469-29642025-05-0110210.20411/pai.v10i2.801Evaluation of Far Ultraviolet-C Light for Decontamination of Organisms in Whole Milk and Chicken ManureSamir Memic0Jennifer Cadnum1Curtis Donskey2https://orcid.org/0000-0003-0990-4498Department of Systems Biology, Case Western Reserve University School of Medicine, Cleveland, OhioResearch Service, Louis Stokes Cleveland VA Medical Center, Cleveland, OhioDepartment of Medicine, Case Western Reserve University School of Medicine; Geriatric Research, Education, and Clinical Center, Louis Stokes Cleveland VA Medical Center, Cleveland, Ohio Background: The dissemination of highly pathogenic avian influenza (HPAI) A(H5N1) in US poultry and dairy cows poses a public health threat. Farm workers caring for infected animals are at risk to acquire infections due to exposure to contaminated milk or poultry feces and secretions. Far ultraviolet-C (UV-C) light could provide continuous decontamination of surfaces and air in agricultural settings, but efficacy against organisms in whole milk or chicken manure is unclear. Methods: We examined the efficacy of far UV-C light against bacteriophage MS2 and methicillin-resistant Staphylococcus aureus (MRSA) in phosphate-buffered saline (PBS), 5% fetal calf serum, whole milk, or 5%, 10%, and 25% chicken manure, both in liquid suspension and dried on surfaces. We also compared the efficacy of 300 mJ/cm2 doses of far UV-C and 254-nm UV-C light against the test organisms in liquid droplets or droplets dried on surfaces.  Results: For both test organisms, far UV-C achieved significantly smaller log10 reductions in whole milk and in chicken manure suspensions than in PBS or 5% fetal calf serum, both in liquid suspension and when dried on surfaces (P<0.0001). In whole milk, average reductions of both organisms with all doses were <1.2 log10 in liquid suspensions and <2.4 log10 when dried on surfaces. We found 254-nm UV-C was significantly more effective in reducing MRSA and MS2 dried on surfaces in whole milk or in 10% chicken manure (P<0.02) but not in liquid droplets (P>0.05) except 5% chicken manure (P<0.001).  Conclusions: Our results suggest that in the absence of prior cleaning and disinfection far UV-C and 254-nm UV-C light technologies may have limited efficacy as an adjunctive method to reduce the risk for transmission of HPAI from surfaces in high-risk settings on farms. https://www.paijournal.com/index.php/paijournal/article/view/801Far Ultraviolet-CDairyHighly Pathogenic Avian InfluenzaChickens
spellingShingle Samir Memic
Jennifer Cadnum
Curtis Donskey
Evaluation of Far Ultraviolet-C Light for Decontamination of Organisms in Whole Milk and Chicken Manure
Pathogens and Immunity
Far Ultraviolet-C
Dairy
Highly Pathogenic Avian Influenza
Chickens
title Evaluation of Far Ultraviolet-C Light for Decontamination of Organisms in Whole Milk and Chicken Manure
title_full Evaluation of Far Ultraviolet-C Light for Decontamination of Organisms in Whole Milk and Chicken Manure
title_fullStr Evaluation of Far Ultraviolet-C Light for Decontamination of Organisms in Whole Milk and Chicken Manure
title_full_unstemmed Evaluation of Far Ultraviolet-C Light for Decontamination of Organisms in Whole Milk and Chicken Manure
title_short Evaluation of Far Ultraviolet-C Light for Decontamination of Organisms in Whole Milk and Chicken Manure
title_sort evaluation of far ultraviolet c light for decontamination of organisms in whole milk and chicken manure
topic Far Ultraviolet-C
Dairy
Highly Pathogenic Avian Influenza
Chickens
url https://www.paijournal.com/index.php/paijournal/article/view/801
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AT curtisdonskey evaluationoffarultravioletclightfordecontaminationoforganismsinwholemilkandchickenmanure