88 STUDY AND IDENTIFICATION OF BACTERIA. 



A very important discovery is that certain persons, who may have 

 had only a slight febrile attack, may eliminate typhoid bacilli for years 

 in their feces (typhoid carriers). The bacilli are also eliminated for 

 considerable periods in the urine. Distinction is now being made 

 between acute carriers (convalescents) and chronic carriers. Or- 

 dinarily, it is very difficult to isolate typhoid bacilli from the stools. 

 For laboratory diagnosis, blood cultures during the first week and 



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FIG. 34. Bacillus of typhoid fever, stained by Loffler's method to show 

 flagella. (X 1000.) (Williams.) 



agglutination tests during the second week and onward are the 

 practical methods. B. typhosus appears in the blood in relapses. 



Paratyphoid Bacilli (Achard and Bensaude, 1896; Schottmiiller, 

 1901). Cases resembling mild attacks of typhoid occasionally show 

 agglutination for paratyphoid bacilli. These organisms have also 

 been isolated from the blood, as with typhoid. Two types have been 

 recognized: the paratyphoid A and the paratyphoid B. The latter 

 occurs in 80% of such cases. Culturally, paratyphoid B cannot be 



