BACILLUS ANTHRACIS 377 



infection may take place through the skin as well. Less commonly 

 cutaneous infection may occur through wounds in cattle and sheep. 

 A localized severe inflammation results which may heal spontaneously 

 or lead to a generalized infection. It is stated that flies, particularly 

 the horse flies (Tabanidse) may transmit the virus to animals. The 

 disease may also be transmitted experimentally by the inhalation of 

 spores; this method of infection is probably not common in animals. 



Human. Anthrax bacilli or their spores may cause disease in man 

 either by gaining entrance to the body through abrasions of the skin, 

 by inhalation, or by ingestion. Inoculation through the skin may 

 give rise to malignant pustule, characterized by a small papule at the 

 site of infection, which soon becomes vesicular. The process may 

 stop spontaneously with the formation of a scab and the gradual 

 drying up of the vesicle, or the inflammation may spread, producing 

 a wide area of induration in which vesicles appear, often in consider- 

 able numbers. The involved area becomes edematous, and the 

 regional glands become enlarged. Death may ensue within five to 

 seven days, or the inflamed area slowly returns to normal. Less com- 

 monly edema is the prominent symptom, pustule formation being 

 absent or not conspicuous. The edematous area spreads rapidly and 

 it may be extensive enough to interfere with the nutrition of the part 

 and lead to gangrene. The head, the arms, or the hands are more 

 frequently involved than the lower extremities. 



Intestinal anthrax and pneumonic anthrax or woolsorters' disease 

 are usually caused by the ingestion or inhalation of anthrax bacilli 

 or their spores. Intestinal anthrax is uncommon; it is supposed to 

 be an infection through the gastro-intestinal tract resulting from the 

 ingestion of meat or milk of diseased animals. The symptoms are 

 essentially those of meat-poisoning: chill, vomiting, and nausea, 

 diarrhea, and some fever. Woolsorters' disease prevails where hides 

 and wool, particularly from South America, Morocco and Russia, are 

 handled. The symptoms are: a sudden chill, immediate great pros- 

 tration, intense pain, bronchial irritation, and occasionally death 

 within twenty-four hours. Cerebral symptoms frequently are promi- 

 nent in those cases which are more protracted. There are no distinc- 

 tive postmortem changes; the lungs may be edematous and there 

 are scattered patches of lobular pneumonia with inflammation of the 

 regional bronchi. 



Immunity and Immunization. The vulnerability of human tissues 

 to anthrax infection is varied; the skin appears to be relatively resis- 



