BACILLUS ANTHRACIS AND ANTHRAX 573 



purulent fluid. This may change into a black central necrosis sur- 

 rounded by an angry red edematous areola. Occasionally local gangrene 

 and general systemic infection may lead to death within five or six days. 

 More frequently, however, especially if prompt excision is practiced, the 

 patient recovers. The early diagnosis of the condition is best made 

 bacteriologically by finding the bacilli in the local discharge. 



The pulmonarj'^ infection, known as "wool-sorter's disease," occurs 

 in persons who handle raw wool, hides, or horse hair, by the inhala- 

 tion or by the swallowing of spores. The disease is fortunately rare in 

 this country. The spores, once inhaled, develop into the vegetative 

 forms ' and these travel along the l5'mphatics into the lungs and 

 pleura. The disease manifests itself as a violent, irregular pneumonia, 

 which, in the majority of cases, leads to death. The bacilli in these 

 cases can often be found in the sputum before death. 



Infection through the alimentary canal may occasionally, though 

 rarely, occur in man, the source of infection being usually ingestion of 

 the uncooked meat of infected animals. This form of infection is rare, 

 because in many cases the bacilli have not sporulated in the animal 

 and the ingested vegetative forms are injured or destroyed by the acid 

 gastric juice. When viable spores enter the gut, however, infection may 

 take place, the initial lesion being localized usually in the smaU intes- 

 tine. The clinical picture that follows is one of violent enteritis with 

 bloody stools and great prostration. Death is the rule. The diagnosis 

 is made by the discovery of the bacilli in the feces. 



General hygienic prophylaxis against anthrax consists chiefly in the 

 destruction of infected animals, in the burying of cadavers, and in the 

 disinfection of stables, etc. The practical impossibility of destroying 

 the anthrax spores in infected pastures, etc., makes it necessary to re- 

 sort to prophylactic immunization of cattle and sheep. 



Immunity against Anthrax. — Minute quantities of virulent anthrax 

 cultures usually suffice to produce death in susceptible animals. Dead 

 cultures are inefficient in calling forth any immunity in treated subjects. 

 It is necessary, therefore, for the production of active immunity to 

 resort to attenuated cultures. The safest way to accomplish such at- 

 tenuation is the one originated by Pasteur,^ consisting in prolonged 

 cultivation of the bacillus at 42° to 43° C. in broth. Non-spore-forming 

 races are thus evolved. 



The longer the bacilli are grown at the above temperature the greater 



> Epfinger, Wien. med. Woch., 1888. ^ Pasteur, loo. cit. 



