Ultraviolet germicidal irradiation and ventilation for avian influenza control in poultry farms: A comprehensive...

The poultry industry faces persistent threats from highly pathogenic avian influenza (HPAI), whose airborne transmission in enclosed barns is exacerbated by high stocking densities, fluctuating humidity, and inadequate ventilation. This review synthesizes current evidence on ultraviolet germicidal irradiation (UVGI) and mechanical ventilation as complementary engineering controls for mitigating infection risks in poultry environments. A systematic search of Web of Science and Google Scholar identified 33 peer-reviewed studies addressing environmental and technological strategies for influenza control. Analysis of collected UVGI data revealed high susceptibility of influenza to ultraviolet exposure, with reported inactivation rate constants ranging from 0.003 to 2.18 m²/J. Based on ventilation literature, tunnel and hybrid systems are associated with improved air quality and lower modelled infection risks. Integrating UVGI with mechanical ventilation may offer complementary benefits: UVGI inactivates pathogens that ventilation alone cannot fully remove, while ventilation regulates humidity and reduces aerosol residence time, thereby improving UVGI performance. This integrated framework may enhance biosecurity, animal welfare, and productivity, providing a potential complement to vaccines and antivirals that are often challenged by rapid viral mutation. In contrast to conventional buildings, however, it is important to emphasize that poultry houses are typically characterized by elevated bioaerosol loads, animal-derived emission sources, constrained ventilation control, high population density, complex layouts, high chicken mobility, and proximity between chickens, resulting in fundamentally different requirements for UVGI-ventilation implementation. The review identifies key research gaps, including the need for full-scale validation, optimization under variable climates, and development of more robust infection control systems.