PATHOLOGY— MORBit) AKUTOMV 



Strong, Crowell, and Teague, from a study of the pathology of 

 Mukden plague, have concluded that epidemic pneumonic plague 

 results from inhalation of the bacilli. The primary infection appears 

 to be the bronchi, while it extends along the bronchioles by con- 

 tinuity into the infundibula and air-cells, or through the walls of 

 bronchioles into the lung tissue, causing a peribronchial inflamma- 

 tion. From these centres the infection spreads to the adjacent 

 pulmonary tissue and to the visceral pleura, the bacilli growing 

 rapidly, and causing first a lobular pneumonia and later a lobar 

 pneumonia, while the blood becomes quickly infected, causing a 

 septicaemia. Secondary pathological changes take place in the 

 spleen, bronchial glands, heart, bloodvessels, kidneys, liver, and 

 tonsils, which may at times become primarily affected. No sign 

 of any intestinal plague was found, although plague bacilli must 

 have been repeatedly swallowed in the bronchial secretions and 

 saliva by the patients. 



Morbid Anatomy. — ^The characteristic features of a plague post- 

 mortem are the haemorrhages and the buboes, which have been 

 studied in detail by Diirck. The skin in the region of buboes 

 and on the head, arms, neck, and shoulders may show haemorrhages, 

 which arise from the action of the toxins upon the endothelial cells 

 of the vessels. These cells increase in size, and perhaps in number, 

 and some macrophages arise, after which they degenerate, and allow 

 haemorrhages by rhexis to take place. These haemorrhages, there- 

 fore, may be petechial or diffuse, and will contain bacilli. Besides 

 these, however, vesicles, pustules, or carbuncles, may be seen. 



The vesicle arises from the irritation caused by the bacilli in the 

 skin, producing inflammation with exudation, which may go on to 

 pustulation, or, the vesicle drying up, the cutis may become much 

 inflamed and degenerated, forming the so-called carbuncle, which 

 in no respect resembles a true carbuncle. 



The primary bubo shows a periglandular infiltration, which may 

 spread from the site of the enlarged glands in all directions. When 

 this gelatinous exudate is cut into, the enlarged glands can be seen 

 matted together, grey or yellowish-grey in colour, with a soft centre 

 and numerous haemorrhagic spots, or perhaps large haemorrhages. 

 The secondary buboes are seen to consist of degenerated glands 

 without the oedema, but with endo- and peri-glandular haemorrhages. 

 The tertiary buboes contain hard hyperaemic glands marked by 

 haemorrhages. 



The muscles of the body, but especially those of the abdominal 

 Wall, will be seen to be haemorrhagic. The spleen is enlarged and 

 congested, and shows haemorrhages and contains bacilli. The liver 

 may be slightly enlarged andhaemorrhagic, with cloudy swelling and 

 fatty degeneration of the cells. The lungs usually show some 

 bronchitis, and often patches of secondary broncho-pneumonia. 

 The right heart is usually dilated, and the musculature shows fatty 

 degeneration, cloudy swelling, and haemorrhage. Primary broncho- 

 pneumonia may, however, exist, and be followed by a septicaemia 



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