[Isolation of the causative agent of ornithosis from gamasid mites].

A microorganism was isolated from Gamasoid mites (Ornithonyssus sylviarum) collected in nests of blue rock pigeons by means of blind passages in white mice and chick embryos. The studies of its morphological, cultural, and antigenic properties and pathogenicity for laboratory animals permitted to identify it as the causative agent of ornithosis. It is suggested that the possibility of infection of ectoparasites is determined to a considerable extent by the degree of activity of the infectious process in the hosts. Ornithonyssus sylviarum may be assumed to be one of additional reservoirs of the causative agent of ornithosis in nature.