196 BACTERIOLOGY FOR NURSES 



The Intracutaneous Test of Mantoux. The test is made as 

 follows : the skin of the forearm is cleansed with alcohol and then 

 with ether and a series of injections of different dilutions of tuber- 

 culin are made intracutaneously. Four dilutions are used : 1 to 

 10,000,000, 1 to 1,000,000, 1 to 100,000, and 1 to 10,000. The 

 amount injected of each is generally 0.1 c.c. A control injec- 

 tion of 0.1 c.c. of sterile normal salt solution is made at the same 

 time. A positive reaction appears in six or eight hours and usually 

 subsides in six to ten days. 



The Percutaneous Test of Moro. Equal parts of lanolin and 

 tuberculin are made into an ointment and a small amount is rubbed 

 into the skin on the chest. A positive reaction appears within 

 one to four days as an eruption of slightly elevated papules. 



The Cutaneous Test of Von Pirquet. The test is carried out 

 as follows : the forearm is cleansed with alcohol and ether and 

 two small scratches are made about three inches apart, care being 

 taken not to cause bleeding. On one scratch a drop of tuber- 

 culin is placed, the other is left as a control. A positive reaction 

 may appear in from three to ten hours as a slightly raised redden- 

 ing of the skin, usually circular and about 10 mm. in diameter. 



Ophthalmic Test of Calmette. For this test either a 2 per 

 cent solution of Koch's old tuberculin or a purified form is used. 

 One drop of the solution is placed in the conjunctival sac and the 

 fluid is allowed to spread over the surface. In a positive reaction 

 the conjunctiva is inflamed. The lids become congested and their 

 inner surface of a bright red color, and varying amounts of a 

 fibrinous exudate appears. The reaction reaches its maximum 

 in from six to ten hours and disappears usually in from two to 

 three days. The ophthalmic test is easily applied, but is little 

 employed, owing to serious dangers that may result. 



So far as is known there is no positive skin reaction without 

 infection. A positive reaction, however, tells nothing of the 

 location or extent of the lesion nor if it is a progressive or an en- 

 capsulated focus. Very advanced cases frequently show little 

 response to tuberculin tests, the tissue cells being evidently in- 

 capable of further effort. 



