[Morphology of influenza in the prodromal period (experimental study)]

The prodromal period of influenza infection was studied in 14 random-bred mice using electron microscopy. The most marked reaction to the invasion of influenza virus virions in the first day was found to develop in large alveolar cells. The defence response of the body in this period was manifested morphologically by a release into the alveolar lumen of plate osmiophilic bodies containing a surfactant, and later by leucocytary infiltration of interalveolar septa. Early in influenza infection pulmonary macrophages took no part in the defence response of the body.