[Experimental slow influenza infection in mice]

In baby mice born to mothers--virus carriers (surviving for various periods after intranasal administration of influenza virus), infectious persisting influenza virus in titres of 10(0.5) to 10(2.5) EID50/0.1 ml was found in the blood, lungs, livers, kidneys, spleens, and brains. Not infrequently, such animals developed a severe pathological process accompanied by growth retardation and characterized by progressive involvement of the hypothalamus, immunocompetent organs, endocrine system and always terminating by the death of the animals. Possible mechanisms of the described slow form of influenza infection are discussed.