[Chronic course of influenza with extrapulmonary involvement].

Results of the investigation of 265 placentas and 387 necropsies with the use of a wide spectrum of morphological, immunological and virological methods are presented. The existence of extrapulmonary damages, those of placenta (50 observations) and brain (17 observations), is shown. The variants of the influenza infection (persisting, chronic and manifesting) are discussed. The possibilities of a long-term survival of the infectious agent in the long-living brain and placental structures are considered. The proofs are presented showing the secretion by these organs of local factors of non-specific defense such as interferon.