Aerosol transmission of infectious diseases in poultry: microbiology, pathogenesis, and control measures

The expansion of intensive poultry production improves productivity but increases the risk of disease transmission. In poultry houses, infectious disease transmission occurs through direct and indirect routes, including surface contamination and vector-borne transmission. Typically, disease control in poultry mostly focuses on direct contact and management-related practices in poultry houses, but there is growing evidence highlighting the significance of the aerosol transmission route - an indirect route of pathogen spread that can impair production performance in poultry. High stocking density in poultry houses, inadequate ventilation, and poor biosecurity measures increase the risk of aerosolized transmission of bacterial, viral, and fungal pathogens. The efficiency of this route depends on particle size, humidity, temperature, and ventilation, which influence pathogen survival and exposure, and is further compounded by environmental stressors and the site of action within the animal's respiratory system. Given that major pathogens, such as avian influenza virus, infectious bronchitis virus, avian orthoavulavirus 1, and Aspergillus spp., are usually transmitted via the aerosol route, it is essential for poultry farmers to adopt a range of mitigation strategies to achieve effective disease prevention and improve production output. As such, this review highlights the role of aerosol transmission in poultry health and management, focusing on microbiological aspects, pathogenesis, overall impact, and mitigation strategies. Also, this review aims to integrate current knowledge on aerosol characteristics with transmission dynamics and to provide insight into future research opportunities.