DIAGNOSIS OF TUBERCULOSIS 453 



believe that the changes in opsonic index furnish a reliable index 

 for treatment with tuberculin or other products of the tubercle bacillus. 

 The inherent and unavoidable errors of the opsonic index determina- 

 tion make it unreliable for general use. 1 



2. Agglutination. Agglutinins occur in tuberculous patients, 2 but 

 the agglutinating reaction is unreliable, partly because of the diffi- 

 culty in obtaining a proper suspension of tubercle bacilli. It is 

 practically never used in practice. 3 



3. Complement Fixation. Practically never used at the present time. 4 

 C. Bacteriological Diagnosis. 1. Principle Involved. (a) Micro- 

 scopical Examination. Fluids, tissues or exudates suspected to con- 

 tain tubercle bacilli are stained preferably by the Ziehl-Neelsen method 

 for the demonstration of acid-fast bacilli having the morphology of 

 the tubercle bacillus. Other acid-fast bacilli may be confused with 

 the tubercle bacillus and their presence must be borne in mind when 

 microscopical examinations are made. These will be discussed under 

 their appropriate headings. 



It is essential to use absolutely new slides for examination of the 

 tubercle bacillus; old slides which have been used for this purpose 

 not infrequently retain tubercle bacilli. It is also advisable not to 

 make a positive diagnosis unless ten typical tubercle bacilli can be 

 demonstrated in the preparation. Among thousands of smears which 

 have been examined by Arms, formerly of the Boston State Board of 

 Health Laboratory, only one has failed to show ten tubercle bacilli, 

 if any were present, after careful search. This one case was shown 

 by many subsequent examinations to be negative for tubercle bacilli. 

 The microscopical examination is the most rapid method of diagnosing 

 tuberculosis bacteriologically. 



(b) Cultural. Cultures of typical bacilli mav be obtained either 

 directly from lesions, fluids, tissues, or exudates, or from animals 

 following inoculation with suspected material. In order to obtain cul- 

 tures of tubercle bacilli from material containing other organisms as well, 

 it is necessary to treat the material first with antiformin 5 from two 



iTrudeau, Am. Jour. Med. Sc., 1907, cxxxiii, 813; Baldwin, New York Mod. Jour., 

 June 27, 1908. 



2 Romberg, Deutsch. med. Wchnschr., 1901, 275, 295. 



3 Eisenberg and Keller, Centralbl. f. Bakt., 1903, xxxiii, 549, for literature. 



4 Stimpson, Bull. 101, Hygienic Laboratory, 1915, for literature. 



6 Paterson, Antiformin for the Detection of Tubercle Bacilli in Sputum. Studies from 

 the Saranac Laboratory for the Study of Tuberculosis, 1904-1910. Sodium carbonate, 

 600 grams; fresh chlorinated lime, 400 grams; distilled water, 4000 grams. Dissolve 

 the sodium carbonate in 1000 c.c. distilled water; triturate the chlorinated lime in 3000 

 c.c. distilled water; filter, and mix with the sodium carbonate solution. Filter again. 



