DIAGNOSIS OF TUBERCULOSIS 8 1 



solution added to 99 c.c. of salt solution, with 1/4% of lysol, would give a working 

 solution, each c.c. of which would contain i/iooo mg. of tuberculin. 



For diagnostic reactions we have, besides the method of injecting 

 tuberculin and noting presence or absence of fever, six more recent 

 diagnostic tuberculin tests: i. Variations in opsonic index. 2. Instil- 

 lation into one eye of a drop of 1/2% or i% solution of purified tuber- 

 culin. Reaction is shown by redness, especially of inner canthus, in 

 twelve to twenty-four hours (Calmette). A previous instillation may 

 sensitize a nontuberculous case and a second application of the drop may 

 give an erroneous diagnosis. 3. The cutaneous inoculation method 

 (similar to ordinary vaccination methods). Scarify two small areas on 

 the arm (i/io inch in diameter), about 2 inches apart. Rub in one 

 a drop of old tuberculin, in the other a drop of 25% tuberculin. As a 

 control scarify a spot midway and to one side of the others and rub in 

 one drop of 0.5% carbolic glycerine. The appearance of bright red 

 papules in twenty-four hours indicates reaction (von Pirquet). This is 

 the method of preference. 4. Intracutaneous inoculation of one drop 

 of a i-iooo, i-ioo or i-io dilution of old tuberculin (Mantoux and 

 Moussu). Webb recommends hypodermic needle points which have 

 been dipped in old tuberculin and the points allowed to dry. A drop 

 of water is placed on the skin and the needle points having been mois- 

 tened in it are plunged through the skin and withdrawn with a twist. 

 A definite lump shows a positive reaction. 5. Ointment tuberculin 

 test. Rub in 50% ointment of tuberculin in lanolin. Reaction is 

 shown by dermatitis with reddened papules in twenty-four to forty- 

 eight hours (Moro). 6. Inoculation of bovine and human tuberculin 

 to diagnose type of infection (Detre). Of questionable value. 



Ebright injects the suspected material into the subcutaneous tissue of one side 

 of the abdomen of three guinea-pigs. At the end of one week an injection into the 

 other side of the abdomen of one of the guinea-pigs of 1/4 c.c. tuberculin is given. 

 Twenty-four hours later smears are made from the original site of inoculation and 

 examined for tubercle bacilli. If negative this is repeated with a second guinea- 

 pig at the end of the second week and finally at the end of the third week with the 

 third guinea-pig. 



Bloch's method is to damage the lymphatic glands in the inguinal region by 

 squeezing the tissue between the fingers. Injections made there of tuberculosis 

 material show abundant tubercle bacilli in these damaged glands in ten to twelve 

 days. 



In staining it is better to use the Ziehl-Neelsen method, decolorizing 

 with 3% hydrochloric acid in 95% alcohol. The alcohol, for all prac- 

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