292 AGGLUTININS 



typhoid bacillus and with the typhoid bacillus. In case of mixed in- 

 fection the absorption method of Castellani will serve to clear up the 

 diagnosis. 



In dysentery the agglutination reaction with the serum of patients 

 shows great variability. In spite of the presence of bacilli in the feces 

 ithe reaction is sometimes absent, often disappears rapidly during con- 

 valescence, and rarely is as high as in typhoid fever. The tests should 

 always be performed with both the "Flexner" and "Shiga" types of 

 bacilli, as the two do not possess identical agglutinable properties, and 

 either may be the cause of infection in a given case. The absence of the 

 reaction does not exclude a dysenteric infection. 



In cholera the agglutination test has so far proved of doubtful aid in 

 establishing a diagnosis of the disease. However, for the purpose of 

 recognizing bacilli isolated from the feces of suspicious cases the reaction 

 with known immune serum is of great value. 



In cerebrospinal meningitis the agglutination occurs within an hour 

 in dilutions of 1 : 10. It is seldom that the patient's serum agglutinates 

 in a dilution higher than 1 : 50. 



In tuberculosis the agglutination reaction has no value as a diagnostic 

 procedure. Koch recommended the agglutination test for the estima- 

 tion of the degree of immunity conferred by tuberculin treatment. As 

 pointed out elsewhere, agglutinins have apparently no antimicrobic 

 influence, but, as with typhoid vaccination, may indicate the degree of 

 reaction and the presence of other antibodies. 



Many strains of tubercle bacilli are almost non-agglutinable. The 

 preparation of a homogeneous emulsion is not easily made, and the results 

 are likely to be confusing and contradictory. 



In plague the agglutination reaction becomes quite marked about 

 the ninth day of the disease too late, however, to be of much practical 

 value in diagnosis. It is occasionally useful, however, for deciding 

 whether a patient in the convalescent stage has really suffered from the 

 disease. 



In Malta fever the agglutination reaction is of considerable value in 

 making the diagnosis. 



In pneumonia the reaction is of value in rapidly differentiating pneu- 

 mococci and as an aid in specific serum therapy (see page 308), and it 

 may also be of aid in making the diagnosis of infection with Bacillus 

 enteritidis and Bacillus botulinus. 



Agglutinins for Treponema pallidum by the sera of rabbits injected 

 with a living and heat-killed culture furnished by Noguchi, were first 



