DYSENTERY 91 



number of persons living in the midst of epidemic dysentery. Liidke 

 vaccinated himself in this way, but later became infected while work- 

 ing with living cultures. He, therefore, concludes that if subcutaneous 

 injections of dead cultures have any protective value, it is of short 

 duration. In a local epidemic in an insane asylum Fuksch vaccinated 

 the men and left the women without treatment, and states that the 

 disease did not spread further among the former while it continued 

 among the latter. Shiga in 1898-1900 vaccinated ten thousand 

 Japanese in localities in which dysentery was prevalent and found that 

 this procedure did not reduce the morbidity but had a most marked 

 and gratifying effect on the mortality. In some localities, while the 

 death-rate among the unvaccinated reached from 30 to 40 per cent., 

 there were no deaths among the vaccinated. The same investigator 

 vaccinated large numbers of the Japanese troops in the war with 

 Russia. At this time he suspended dead bacilli in antitoxic serum and 

 made three injections at intervals of three or four days, increasing 

 the size of the dose at each injection. 



There can be no doubt concerning the causal relation of these 

 bacilli to dysentery in man. As has been stated, high dilutions of the 

 blood of those sick agglutinate cultures of these bacilli. This is posi- 

 tive evidence, but there is confirmatory proof. Strong fed pure cul- 

 tures of the Shiga bacillus to two criminals sentenced to death, and 

 both developed typical dysentery. Jehle drank mixed Shiga and Flex- 

 ner cultures and developed the disease on the third day. He found 

 both bacilli in his stools. Several accidental laboratory infections have 

 occurred. 



Each of these bacilli produce typical dysentery with characteristic 

 symptoms and lesions. The Shiga bacillus is the most virulent, but 

 otherwise the results are the same. Close study shows that the varie- 

 ties of these bacilli might be multiplied, but while this is of scientific 

 interest it is not of great practical importance. These bacilli are dis- 

 tributed all over the world, having been found in all climes and among 

 all conditions of men. 



Sources of Infection. Like typhoid fever, dysentery is always due 

 to the transfer of the excreta of one person to the ingesta of 

 another. In the great majority of instances the infection is 

 transferred through contact, which may be direct or indirect. The 



