14 



MASS. EXPERIMENT STATION BULLETIN No. 284 



liicul)ator (iisiiifoction should he regarded as part of the general sanitary program 

 and not as a disease eradication measure in its(>lf. 



35. — How may carriers of this disease be detected.' Infeeted hirtls may 

 be detected by the following tests: Intradermal test; macroscopic agglutination 

 test; rapid serum agglutination test; and whole blood agglutination test. 



36. — What is the intradermal, pullorin, or "wattle" test? This test 

 consists of injecting a biological preparation into the skin of the wattle. If a 

 swelling appears at the point of injection within a certain limit of time, the bird 

 is regarded as infected. 



37. — Is the intradermal test reliable in eradicating infection from a 

 flock.' Leading investigators are of the opinion that the test in its present state 

 is not as reliable as other tests which are employed for eradication of the disease. 



38. — What is the macroscopic tube agglutination test.' In general 

 this test consists of the following steps: all birds are legbanded; a small amount 

 of blood is taken from the bird and the sample labelled with the legband number; 

 a small portion of serum is i-emoved from the l)lood sample to a tube containing 



Photojiraph 1.^. — Macroscopic Tube Agglutination Test. 

 The tube on the left shows a negative reaction, and the tube on the right shows a 

 positive reaction. Refer to question ,^8. 



