OOMPUCATH Ml 



ditions may favor infection is indicated by the fre- 

 quency with which individuals with chronic tuber- 

 culosis of the lungs die of pneumococcus pneumo- 

 nia, and the development of the disease in areas 

 of hypostatic congestion. Age is of influence. "To 

 the sixth year the predisposition to pneumonia is 

 marked; it diminishes to the fifteenth year, but 

 then for each subsequent decade it increases" 

 (Osier). The cause of these variations is not 

 known, although the rise in later years may be 

 associated with increased exposure. 



The conditions which predispose to infection are 

 now the subject of active study in many labora- 

 tories, and the commission which the Xew York 

 Department of Health established for the study of 

 acute respiratory diseases made important observa- 

 tions as to the prevalence and virulence of pneurao- 

 cocci. 



Many observers have found pneumococci in the ce 

 blood in a large percentage of the cases, and recent 

 work by Rosenow indicates that the blood is prob- 

 ably infected in all cases at some stage of the dis- 

 ease. This being the case, the frequency with which 

 pneumococcus infections occur in other organs as 

 complications of pneumonia is readily understood. 

 Pleuritis is present almost constantly, pericarditis 

 frequently, and the peritoneal cavity is invaded not 

 infrequently by way of the diaphragm, with general 

 peritonitis as the occasional result. In pneumo- 

 coccus pleuritis the exudate is frequently of a 

 serous character. Endocarditis, meningitis and 

 arthritis are frequent complications. Conjunctivi- 

 tis, otitis media, cutaneous or subcutaneous infec- 

 tions, intramuscular abscesses and osteomyelitis 



