Bioaerosols and airborne spread of diseases in animal production operations

动物疾病具有许多经济和社会影响，并正在成为对畜牧业和公共卫生的新全球威胁。禽流感就是一个例子，它给全球家禽业造成了巨大的经济损失，并对公众健康构成重大威胁。了解动物疾病传播的潜在机制对于预防和管理疾病暴发至关重要。动物疾病传播的一个重要途径是通过生物气溶胶进行空气传播。与直接接触传播相比，空气传播鲜为人知，也更难控制。动物疾病的空气传播与动物活动中产生的生物气溶胶的排放和扩散密切相关。生物气溶胶是由生物材料的碎片或含有活生物体而产生的空气微粒。在动物养殖中，生物气溶胶是由动物、饲料、垫料和粪便产生的，它们由生物、微生物和无机颗粒的复杂混合物组成。当排放到大气中时，这些生物气溶胶作为病原体的载体在空气中传播，并可能感染附近的动物设施。一个简单但关键的研究问题是：与生物气溶胶相关的病原体在大气中传播多远还能存活？提出的研究将探索病原体在养猪操作中雾化的机制，并将开发一种空气传播模型来预测疾病的传播。本研究的新颖之处在于将病原体的生物学模型与气溶胶扩散理论相结合。PRRS（猪繁殖和呼吸综合征）是一种重要的猪疾病，每年给加拿大养猪业造成1.3亿美元的损失，它将作为一个模型进行研究。拟议的研究将为在动物疾病暴发时制定控制和根除决策的工具提供一个理论框架。这不仅有利于加拿大畜牧业最大限度地减少动物疾病造成的经济损失，而且有利于公众减少人畜共患疾病传播的风险。通过拟议的研究计划，两(2)名博士，两(2)名硕士和五(5)名本科生将在涉及工程与动物科学和微生物学等生物科学相结合的多学科环境中接受培训。该研究项目还将为学生提供充足的机会与畜牧业合作，为他们未来的职业生涯做好准备。**

Animal diseases have numerous economic and social impacts and are becoming an emerging global threat to the livestock industry and public health. An example is avian influenza, which has caused huge economic losses to the poultry industry globally and is a significant threat to public health. Understanding the mechanisms underlying the transmission of animal diseases is critical in preventing and managing disease outbreaks. An important route of animal disease transmission is airborne transmission by bioaerosols. In contrast to transmission by direct contact, airborne transmission is less understood and much more difficult to control. Airborne transmission of animal diseases is closely related to emission and dispersion of bioaerosols generated in animal operations. Bioaerosols are airborne particles originated from the fragmentation of biological materials or containing living organisms. In animal operations, bioaerosols are produced from animals, feed, bedding, and feces, and they consist of a complex mixture of biological, microbial, and inorganic particles. When emitted to the atmosphere, these bioaerosols act as a carrier for pathogens that travel in the air and may infect nearby animal facilities. A simple but critical research question is: how far can the pathogens associated with bioaerosols travel in the atmosphere and still be viable? The proposed research will explore the mechanisms by which pathogens are aerosolized in swine operations and an airborne transmission model will be developed for forecasting disease spread. The novelty of this research is to integrate biological models of pathogens with the theory of aerosol dispersion. PRRS (porcine reproductive and respiratory syndrome), which is an important swine disease that costs $130 million to the Canadian swine industry annually, will be studied as a model. The proposed research will provide a theoretical framework for developing tools for making control and eradication decisions in the event of an animal disease outbreak. This will benefit not only the livestock industry in Canada in terms of minimizing economic losses caused by animal diseases but also the general public in terms of reducing the risk of zoonotic disease transmission. Through the proposed research program, two (2) PhD, two (2) MSc and five (5) undergraduate students will be trained in a multidisciplinary environment involving integration of engineering with such biological sciences as animal science and microbiology. The research pogrom will also provide ample opportunities for the students to work with the livestock industry to prepare them for their future careers with the industry. **