BACTERIA IN YELLOW FEVER. 453 



the case of the stomach, the " black vomit " one of the 

 clinical signs of the disease in its worst form. Anuria, 

 coma, and cardiac collapse usher in a fatal issue. The 

 mortality varies in different epidemics from about 35 to 99 

 per cent of those attacked. Both white and black races 

 are susceptible, but those who have resided long in a 

 country are less susceptible than new immigrants. An 

 attack of the disease usually confers complete immunity 

 against subsequent infection. 



On making a post-mortem examination the stomach is 

 found in a state of acute gastritis, and contains much 

 altered blood derived from haemorrhages which have 

 occurred in the mucous and submucous coats. The 

 intestine may be normal, but is often congested and may 

 be ulcerated ; the mesenteric glands are enlarged. The 

 liver is in a state of fatty degeneration of greater or less 

 degree, but often resembling the condition found in 

 phosphorus poisoning. The kidneys are in a state of 

 intense glomerulo - nephritis, with fatty degeneration of 

 the epithelium. There is congestion of the meninges, 

 especially in the lumbar region, and haemorrhages may 

 occur. The other organs do not show much change, 

 though small haemorrhages under the skin and into all the 

 tissues of the body are not infrequent. In the blood a 

 feature is the excess of urea present, amounting, it may be, 

 to nearly 4 per cent. 



Bacteria in Yellow Fever. A very full research into 

 the bacteriology of yellow fever was that of Sternberg 

 (1890), who made cultures from various organs which had 

 been kept for some days at room temperature. Of the 

 organisms isolated one which he named " bacillus x " 

 appeared possibly to have some causal relationship to the 

 disease. Sanarelli (in 1897) obtained cultures of the staphy- 

 lococcus aureus and albus, B. coli, and of an organism which 

 he named bacillus icteroides, and which he considers to be 

 the cause of yellow fever. It is probably identical with the 

 " bacillus x." 



Bacillus Icteroides. This is a bacillus belonging to the 



