CHAPTER XII. 

 INFECTIVE GRANULOMATA. 



Infective granulomata emljraces a group of specific inflam- 

 matory condititins characterized by the proliferation of endijthe- 

 lial cells, fibroblasts and other cells. Though the consideration 

 of the followino- diseases belongs more prijperly to a discussion 

 of infective diseases, their description will be of value to the stu- 

 dent of general pathology. 



TUBERCULOSIS. 



Tuberculosis is a specific, infective disease, caused by the 

 bacterium of tulierculosis aft'ecting ])ractically all of the higher 

 animals and also some of the lower forms of animal kind. 



Extent. — Mcl'arland stales that H^/c of the deaths in the hu- 

 man familv are from tuberculosis. It is probable that 2.j% of 

 all humans hax'e iir ha\-c had tuberculosis. 



The prevalence of animal tul)erculosis is ^•ariablc in dift'erent 

 communities, the percentage depending upon methods emplovcd 

 for contnil and eradication under difTerent sanitar\- laws, U])on 

 transp/Ortation rules and regulations and upon the conditions un- 

 der which the animals are maintained. The exact percentage of 

 tubercular animals in anv countrv is ncit known, but the relative 

 number has been determined b^- tul)erculin testing and In- post- 

 mortem examination at abattoirs. In the Ignited States the 

 percentage, gencrallv s]:)eaking, is low in comparison with other 

 countries. According to the prist-mnrtem findings of 7,fi-31,T17 

 cattle slaughtered in United States establishments having official 

 inspection during the fiscal year beginning Julv 1st, lOOfi, and 

 ending June HOth, 1!K)7, ■?0,S3.">, i. e., .-I'X were tubercular. 

 This percentage is probably below the actual percentage, as 

 dairv cattle are more extensively affected than beef cattle. The 

 Secrctar^' of Agriculture m his report for 19(18 holds that 1% 

 of beef cattle and \0'/c of dairv cattle are tuberculous. 



According to the abo\'e report 2% is the estimated prevalence 

 in the United States of tuberculosis among swine. 



Porcine tuberculosis is apparently on the increase in the 

 United States. In Germany it varies from 1-7%. Equine tuber- 



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