Validation of bulk tank milk sampling strategies and identification of risk factors for Salmonella Dublin in dairies

都柏林沙门氏菌是魁北克省自2011年以来在牛和人中发现的一种新病原体。它会导致奶牛的生产损失、疾病和死亡，并可能导致人类的严重疾病。牛奶巴氏杀菌是控制乳制品中这种病原体的有效方法，因此，识别感染都柏林链球菌的奶牛群对于确保受感染牛群的牛奶不被用于生产原料奶产品具有极其重要的意义。此外，识别导致这种感染在奶牛场引入的风险因素可能有助于更好地控制这种疾病。然而，目前我们还没有一种诊断测试，可以用来准确地确定奶牛场是否受到感染。这项研究的目的是开发一种诊断策略，基于对散装牛奶的多个不完美诊断测试的使用，这些测试在不同的时间间隔进行，散装牛奶是一种很容易收集的介质，在魁北克和加拿大的所有奶牛场都可以获得。将比较不同抽样策略的经济和诊断效率。最后，将确定可能导致乳牛场感染都柏林沙门氏菌的风险因素，以便乳制品生产商能够更好地防止这种疾病在他们的牛群中传播。

Salmonella Dublin is an emerging pathogen in cattle and humans in the province of Québec since 2011. It causes production losses, illness, and death in dairy cattle and can lead to serious illness in humans. Milk pasteurization is an efficient method for controlling this pathogen in dairy products and, thus, identifying dairy herds infected with S. Dublin is of tremendous importance to ensure that milk from infected herds are not used for production of raw-milk products. Moreover, identifying risk factors leading to introduction of this infection in dairies could help better control this disease. Currently, however, we do not have a diagnostic test that could be used to determined without error if a dairy is infected. The aim of this research is to develop a diagnostic strategy based on the use of multiple imperfect diagnostic tests, conducted at different intervals on bulk milk, a media that is readily collected and available on all dairies in Québec and Canada. The economic and diagnostic efficiency of the different sampling strategies will be compared. Finally, the risk factors that could potentially lead to acquisition of Salmonella Dublin infection in dairies will be identified, so that dairy producers can better prevent introduction of this disease in their herd.