420 PATHOGENIC MICROORGANISMS 



in measles bronchopiieumonias, and for both measles and influenza 

 much information has been gathered during the late war. It appears 

 that both measles and influenza, as well as perhaps some other mild 

 infections of the upper respiratory tract, render the individual 

 tremendously susceptible to secondary infection. Under conditions 

 such as those developed in the camps during the war, these strep- 

 tococcus bronchopneumonias may become epidemic, probably by 

 reason of the generalized interchange of mouth organisms among 

 susceptible individuals crowded together under camp conditions. 

 Epidemiologically, it is of interest to note that under these condi- 

 tions the carrier rate of hemolytic streptococci reaches high per- 

 centages. Irons and Marine, 56 at Camp Ouster, found 70 per cent 

 of the individuals examined to be carriers of these organisms, and 

 Levy and Alexander 57 in certain regiments found 89 per cent to be 

 carriers. Given, at the same time, extensive outbreaks of measles 

 and influenza, the conditions for widespread secondary streptococcus 

 pneumonias are established. It is not impossible that widespread 

 ward infection may occur, in that patients who enter hospitals with 

 measles and influenza, even without being carriers of hemolytic 

 streptococci, may pick them up in the hospitals from adjacent beds, 

 from doctors or from nurses, possibilities which indicate the great 

 importance of prompt removal of cases developing pneumonias from 

 measles and influenza wards, the careful hygiene of the mouths 

 and throats of such cases, isolation of beds by screening, and the 

 wearing of masks by doctors and nurses, not so much for their own 

 protection as for that of the susceptible patient. MacCallum, Cole 

 and Dochez 58 made careful studies of the streptococcus pneumonias 

 occurring at some of the camps. The pathological facts resulting 

 from this study are reported by MacCallum in the 10th Monograph 

 of the Rockefeller Institute, issued in 1919. According to him, the 

 streptococci seem to extend downward into the smaller bronchioles, 

 giving rise to intensive inflammations in the air passages, then ex- 

 tending into the network of lymphatics surrounding the bronchioles 

 and the pleura. There was a rapid production of pleurisy and 

 empyema, with hemorrhage about the bronchioles and a very curious 

 infiltration of the alveolar walls themselves with leucocytes chiefly 



66 Irons and Marine, Jour. A. M. A., 70, 1918, 687. 



57 Levy and Alexander, Jour. A. M. A., 1918, 1827, Vol. 70. 



68 MacCallum, Cole and Dochez, Jour. A. M. A., 70, 1918, 1146. 



