THE COLON, TYPHOID AND DYSENTERY BACILLI 349 > 



the agglutination titre of a serum more accurately than has pre- 

 viously been possible. A standard agglutinable culture is em- 

 ployed. This is a formolized suspension of B. typhosus prepared so 

 as to possess a standard opacity and a definite agglutinability. 

 By this method it has been possible to demonstrate a distinct in- 

 crease in agglutinins from the sixteenth to the twenty-fourth 

 day of typhoid fever. Professor Dreyer and his followers have 

 employed this test to diagnose enteric fevers (typhoid and para- 

 typhoids) in patients who had been previously inoculated with 

 the corresponding bacterial vaccines. Pappenheimier^ has dem- 

 onstrated conclusively, however, that such a rise in agglutinins 

 in inoculated men is not a reliable criterion for diagnosis. In 

 such cases the diagnosis of typhoid fever can be proven only by 

 detection of the typhoid bacillus, or by the demonstration of the 

 typical pathological changes at autopsy. 



Transmission of the disease takes place in a variety of ways. 

 To the best of our knowledge, the typhoid bacilli come only from 

 human individuals infected with them. Some of these actually 

 suffer from typhoid fever, while others are merely healthy carriers 

 of the infection. From them as centers the bacilli are distributed 

 by contact and by intermediate object. B. typhosus is able to 

 live for a considerable time in the external worl^, probably for 

 one to three weeks in ordinary surface waters and longer in soU. 

 It is able to grow and multiply in some foods, especially milk. 

 Water supplies contaminated with feces and urine from patients 

 or from healthy carriers have unquestionably been an important 

 factor in the causation of typhoid fever in the past, and the pro- 

 vision of a supply of drinking water free from all suspicion of 

 recent mixture with sewage is the first step in the control of this 



Walker, ibid., Sept. a, 1916, p. 419; Walker, ibid., Nov. 25, 1916, p. 896; Dreyer, 

 Gibson and Walker, ibid., Apr. 8, 1917, p. 766; Walker, ibid.. Vol. I, p. 17. Walker, 

 ibid., April 14, 1917, p. 568; Dreyer and Inman, ibid., March 20, 1917, p. 365. 

 Fennel, Journ. Amer. Med. Assn., 1918, 70, p. 590. 



1 Pappenheimer, Trench F^ver — Report of Commission, Medical Research 

 Committee, American Red Cross, Oxford Press, 1918, pp. 80-142. 



