MICROBIAL DISEASES OF MAN AND DOMESTIC ANIMALS 833 



TUBERCULOSIS* 

 Bacterium tuberculosis 



Consumption, phthisis, scrofula, pearl disease, etc., are synonyms 

 of the term tuberculosis. 



This bacterium in its several varieties produces a very universal 

 disease; practically all common animals and man are subject to it. 

 Cattle and swine among the domestic animals are especially susceptible 

 to this infection and wild animals in captivity easily become affected. 



The normal progress of tuberculosis is slow. Its characteristic 

 feature is the tubercle or nodule of various sizes. 



Tuberculosis is probably the most common and serious of all diseases 

 for either animal or man. 



In 1918, 150,000 persons died from tuberculosis in the United States, 

 or at the rate of 150 per 100,000 population. Based upon these facts, 

 it is estimated that about 10,000,000 of those now living in the United 

 States may die of the disease. It is claimed that the disease alone costs 

 the United States from $400,000,000 to $1,000,000,000 each year 

 (Fisher). 



If the loss from wage earnings, the cost of the patient in suffering, 

 medical treatment, medicines, nursing, board, and care, also the suffer- 

 ing and sacrifice entailed by near relatives, friends, and communities 

 are considered, the loss to the country mentioned above does not appear 

 so enormous. 



It is estimated by the United States Bureau of Animal Industry that 

 2 per cent of hogs in the United States are tubercular, and that losses of 

 stock in the United States, due to tuberculosis, amount to $23,000,000 

 annually. Of 400,000 cattle tested in many states of the United States 

 during a certain period 9.25 per cent were tubercular. The highest 

 prevalence of tuberculosis in cattle is among pure bred herds and in 

 city dairy stables; i.e., among the cattle kept most closely confined. 

 It is most common in old cattle and rare in calves under six months 

 old. Tuberculous infection is quite generally scattered among cattle 

 of civilized nations. 



Tuberculosis appears in man usually in the form of lupus (tubercu- 

 losis of the skin), or scrofula (tuberculosis of the cervical glands), or 



* Prepared by M. H. Reynolds. 

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