[The epidemiology of Q fever].

Q fever as one of infections with natural foci is characterized by epidemic outbreaks. Biologic plasticity and ecologic peculiarities of Coxiella determine its wide distribution and development of Q fever infections which are disseminated almost every-where. They occur in two, i. e. natural and agricultural types of foci. Present paper characterizes their structures, maintenance and peculiarities if their existence. It should be emphasized that single cases of disease as well as outbreaks of Q fever originate usually from agricultural foci, where the source of the infection are livestock, sheep and goats. Data are presented on the involvement of these animals into circulation of coxiellae in various countries of the world. It was shown that agricultural foci of Q fever depending upon close connection with domestic animals are determined in many aspects by basic factors of an epidemic process of the infection, i. e. seasonal occurrence, social conditions, professional relations, etc. which also enhance the course of the infection. Principles on prophylaxis complete the given paper.