Background

Q fever is a zoonosis caused by Coxiella burnetii. In humans, although it has been predominantly considered an occupational hazard, in the last decades, Q fever outbreaks have also been reported in various countries, indicating its importance as an emerging public health threat. Domestic ruminants are considered as the most important sources of human infection. In fact, both symptomatic and asymptomatic infected ruminants shed the bacterium into the environment with birth products, but also in urine, faeces, vaginal mucus and milk. Q fever in humans is mainly asymptomatic, but it also may manifest itself as an acute or chronic disease with long-term sequelae. Inhalation of infectious aerosols usually causes the disease in humans, but the presence of C. burnetii in raw milk raises concern over the role of milk as a source of infection.

Scope and approach

In this review data on Q fever in humans are summarized and the possible transmission of C. burnetii to humans by consumption of unpasteurized milk is discussed. In addition, an overview of the published data on the prevalence studies of C. burnetii in raw milk in various countries is provided.

Key findings and conclusions

Recent surveys conducted in many countries have revealed that the prevalence of C. burnetii in raw milk can vary over a wide range from 0% to as high as 95%. Based on recent survey data, the risk of C. burnetii infection by consuming unpasteurized milk and raw milk products cannot be considered negligible.

中文翻译：

---

牛奶中Q发热和伯氏柯氏杆菌的患病率

背景

Q热是由伯氏柯氏杆菌引起的人畜共患病。在人类中，尽管人们普遍认为它是一种职业危害，但在过去的几十年中，许多国家也报告了Q病暴发，表明其作为正在出现的公共卫生威胁的重要性。家庭反刍动物被认为是人类感染的最重要来源。实际上，有症状和无症状的反刍动物都将细菌与出生产物一起释放到环境中，而且在尿液，粪便，阴道粘液和牛奶中也将其释放到环境中。人类的Q热主要是无症状的，但也可能表现为具有长期后遗症的急性或慢性疾病。吸入感染性气溶胶通常会在人类中引起该病，但生乳中存在伯氏梭菌（C. burnetii）引起了人们对牛奶作为感染源的作用的担忧。

范围和方法

在这篇综述中，总结了有关人类Q发热的数据，并讨论了食用未经巴氏消毒的牛奶可能将伯氏梭状芽胞杆菌传播给人类的情况。此外，还提供了有关在不同国家/地区未加工牛奶中伯氏梭状芽胞杆菌患病率研究已发表数据的概述。

主要发现和结论

在许多国家进行的最新调查显示，生牛奶中伯氏梭状芽胞杆菌的患病率可以在0％至95％的很大范围内变化。根据最近的调查数据，通过食用未经巴氏消毒的牛奶和生奶产品感染伯氏梭状芽胞杆菌的风险不能被忽略。