BACTERIUM INFLUENZA 119 



form usually, but sporadic cases also occur. The 

 organisms are carried in the nose and throat and 

 communicated to others in the fine particles coughed 

 or spat out. They lodge on the mucous surfaces and 

 produce an inflammation through which the poisons 

 are absorbed. The rods themselves do not usually 

 enter the blood stream, and their poisons are largely 

 extracellular. They may enter the blood, as is attested 

 by the fact that there are influenzal forms of pleuritis 

 and pericarditis, diseases probably not due to an 

 extension by continuity. Influenzal pneumonia occurs 

 when the bacteria penetrate to the lung tissue proper. 

 It is comparable in development to the pneumonia 

 caused by the pneumococcus. The bacillus may at 

 times form pus. 



The attack of influenza runs an acute course. It 

 leaves but a transient immunity, and one attack is said 

 actually to predispose to another when the individual 

 is exposed subsequently. As complications of influenza 

 of the upper air passages we may have pus in the 

 sinuses about the nose, or otitis media. 



While influenza is an acute disease and the bacteria 

 are actively virulent during an attack, it is believed 

 that they remain in the upper air passages in abey- 

 ance and not producing disease for long periods after 

 the acute symptoms have subsided. When they are 

 received in sputum particles upon the nose or mouth 

 of another person not resistant to them, they regain 

 their activity and inflame the parts. They are said 

 to remain in the lung tissue for a long time until 

 some reduction of the person's resistance permits 

 the lighting up of a pneumonia. 



