i426 



PLAGUE 



and bubo formation. The stomach is hyperaemic and haemorrhagic, 

 while the soUtary glands and Peyer's patches of the intestine are 

 swollen and the mesenteric glands enlarged. The kidney may be 

 normal, or show haemorrhages. The nervous system seldom shows 

 any changes, but haemorrhages and meningitis may occur. 



The post-mortem appearances of plague in rats are : — ■ 



Bubonic Type. — Lymphatic glands enlarged and haemorrhagic, liver and 

 spleen enlarged and congested; the former shows granular degeneration of a 

 peculiar nature, and the latter is speckled with whitish spots as seen on section. 

 There is often fluid in the pleural sacs. These features have been found useful in 

 diagnosis of plague rats when microscopical examinations cannot be carried out. 



SepticcBmic Type.- — -There are no characteristic macroscopic features, and 

 the diagnosis is solely based upon microscopic findings of the splenic juice 

 and heart bJood. 



Doell and Warner have applied to the diagnosis of plague infection in rats 

 Ascoli's thermoprecipitation method. 



In cases of acute septiccemic type there is no post-mortem charac- 

 teristic feature on which the diagnosis of plague may be made or 



even suspected. The lym- 

 phatic glands are not 

 enlarged, though the spleen 

 may be of larger size than 

 normal. 



Symptomatology — Incuba- 

 tion. — The incubation period 

 varies from two to ten days, 

 the average being three 

 days. During this period 

 there may be prodromal 

 symptoms in the form of 

 general malaise, headache, 

 gastro-intestinal disturbance, 

 pain , or feeling of discomfort 

 in the site of the future bubo, chilliness, giddiness, and mental dulness. 



Onset. — -The onset is usually sudden, with rise of the temperature 

 to 103° to 104° F., pulse of 120, and respirations 30 to 40, and marked 

 prostration, with an aggravation of the prodromal symptoms — i.e.. 

 severe headache, furred tongue, vomiting, at times diarrhoea, pains 

 in the back and limbs, and at the site of the future bubo, marked 

 chilliness or a rigor, staggering gait, and marked mental dulness. 



Course. — In a few hours the disease becomes properly established, 

 when the patient presents a typical facial expression of fear or 

 anxiety, the eyes being bloodshot, bright, and staring, the face drawn 

 and the nostrils dilated. The temperature rises during the first day, 

 but may remit a degree or so on the second day, but if so, it rises 

 quickly again to the same or a higher degree than at first. As a 

 rule, however, the temperature is most irregular. Towards the end 

 it may fall by lysis, if recovery is to take place, or fall rapidly to 

 normal or subnormal, and then as rapidly to rise about 107° F., or 

 may simply rise directly to about 107° F., and death ensue. There 



Fig. 670. — Temperature Chart 

 OF Plague. 



