CHAPTER XI. 

 BUBONIC PLAGUE. 



BACILLUS PESTIS (YERSIN, KITASATO). 



General Characteristics. A minute, pleomorphous, diplococcoid 

 and elongate, sometimes branched, non-motile, non-flagellated, non- 

 sporogenous, non-chromogenic, aerobic and optionally anaerobic, 

 pathogenic organism, specific for bubonic plague, easily cultivated 

 artificially, and susceptible of staining by ordinary methods, but not 

 by Gram's method. 



Plague, bubonic plague, pest, or malignant polyadenitis 

 is an acute infectious febrile disease of an intensely fatal 

 nature, characterized by inflammatory enlargement and 

 softening of the lymphatic glands, marked pulmonary, 

 cerebral, and vascular disturbance, and the presence of the 

 specific bacillus in the lymphatic glands and blood. 



It is an extremely fatal affection, whose ravages in the 

 hospital at Hongkong, in which Yersin made his original 

 observations, carried off 95 per cent, of the cases. The 

 death-rate varies in different epidemics from 50 to 90 per 

 cent. In the epidemic at Hongkong in 1894 the death-rate 

 was 93.4 per cent, for Chinese, 77 per cent, for Indians, 60 

 per cent, for Japanese, 100 per cent, for Eurasians, and 18.2 

 per cent, for Europeans. It affects both men and animals, 

 and is characterized by sudden onset, high fever, prostration, 

 delirium, and the occurrence of painful lymphatic swellings 

 "buboes affecting chiefly the inguinal glands, though not 

 infrequently the axillary, and sometimes the cervical, 

 glands. Death comes on in severe cases in forty-eight 

 hours. The pneumonic form is most rapidly fatal. The 

 longer the duration of the disease, the better the prognosis. 

 Autopsy in fatal cases reveals the characteristic enlargement 

 of the lymphatic glands, whose contents are soft and some- 

 times purulent. 



Wyman,* in his very instructive pamphlet, "The Bu- 

 bonic Plague," finds it convenient to divide plague into (a) 

 bubonic or ganglionic, (6) septicemic, and (c) pneumonic 

 * Government Printing Office, Washington, D. C., 1900. 

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