ANTHRAX 85 



Avenues of Infection. The virus may find admission to the animal 

 body subcutaneously, intravenously, by feeding or by inhalation. A 

 break in the continuity of the skin or mucous membrane may afford a 

 port of entry. Even in feeding the point of entry may be in the 

 mouth, pharynx or esophagus, caused by a slight wound. Especially 

 is this true in animals in which slight wounds may be caused by hard 

 bits of food, dust or other accidental constituents. The dried spores 

 may infect through any of these avenues quite as effectively as the 

 vegetative forms. The spores are especially suitable for infection by 

 inhalation. Moreover, in feeding, the spores are more resistant than 

 the vegetative forms to the acid of the gastric juice. While the blood 

 may be free from bacilli in the first stage of the disease and while in 

 rare non-fatal cases the infection may remain localized, in most 

 instances the blood becomes a vehicle for the transport of the virus 

 and it reaches every part of the body. The bacilli are eliminated from 

 infected animals with the urine and feces. They have been found in 

 milk drawn from sick cows a short time before death. The fetus in 

 utero may become infected. This has been observed in both lower 

 animals and man. In epidemics, fields, barnyards and stalls become 

 infected and the most common port of entry is the mouth. The feces 

 and urine of infected animals pollute all about them and the virus is 

 easily and quickly transferred to the well. Naturally, anthrax devel- 

 ops, in epidemics, among men who are brought into close contact with 

 the sick animals. In Russia from 1904 to 1909 the average annual 

 deaths from anthrax among men numbered sixteen thousand ; in Italy 

 from 1890 to 1900, about two thousand one hundred. In 1910 the 

 number of persons infected with anthrax in Germany is given as 2S7, 

 with 40 deaths. Certain occupations, such as butchers, tanners, sheep 

 shearers, furriers and glove makers, shoemakers, saddlers and harness 

 makers, dealers in hay and grain, and wool-sorters, are especially 

 exposed to this infection. The primary infection in man is most fre- 

 quently through slight wounds on the skin where malignant pustules 

 form. The lungs may be infected through inhalation. Intestinal 

 infection in man, though infrequent, has been reported. Fruit and 

 vegetables may be polluted by the urine or feces of animals and may 

 carry the virus into the alimentary canal. 



