202 STATE BOARD OF AGRICULTURE 



Comparison of Serological Test hy Different Laboratories. 



For the past eight months Dr. C. P. Fitch of the University of Minne- 

 sota and myself have been exchanging blood samples from cattle for 

 the purpose of comparing the diagnostic tests (agglutination and comple- 

 ment fixation) in use at the two laboratories in order to determine 

 whether the results from his technic and our technic agree. Agreement 

 in results by all laboratories is very essential if the tests are ever to be 

 placed on a universal diagnostic basis. 



Up to the present time we have conducted these tests on about 300 

 samples of serum. The tests show that there is a considerable difference 

 in our results. By slight changes in technic we hope to bring our re- 

 sults into complete agreement. 



3. Ca/rriers. 



Considerable progress has been made on this pro'blem, but not suffi- 

 cient to warrant a definite statement except on the destruction of the 

 carrier state. 



In order to destroy in a host a microparasite which appears to have 

 therein a permanent abode, one must consider those agents which (1) 

 increase the defensive mechanism of the host and (2) destroy the para- 

 site directly. 



Concerning the former, sufficient data have been collected to show 

 that killed and living (non-virulent) cultures, bacterins, and vaccines, 

 have no effect upon the carrier state. The direct action of one agent 

 "collargol" on the organism in the body is reported below. 



The Treatment of Bovine Infectious Abortion With Collargol. 



Ziemann, in 1921, reported considerable success in the treatment of 

 malta fever in humans by means of collargol. Since the organism con- 

 cerned in the etiology of malta fever and in infectious a'bortion are in 

 many respects similar if not identical, it was thought that this agent 

 might prove to be of considerable value in the treatment of animals in- 

 fected with Bad. abortus. 



Two groups of dairy cows were used in this experiment. The first 

 group consisted of 16 cows. Blood tests were made on all animals on 

 Nov. 13, 1922, of which 5 gave positive reactions. Of these 2 had prev- 

 iously aborted. On November 24, 1922, the 5 reacting animals received 

 intravenously 20 cc. of a 2 per cent aqueous solution of collargol. 



One of the treated cows aborted a 5-months fetus January 1, 1923, 

 and one untreated cow aborted a 7-nionths fetus February 1, 1923. On 

 May 2, 1923, blood tests were again made on the entire herd. The five 

 treated animals which formerly reacted were positive, including the 

 negative reactor which aborted February 1, 1923. 



The second group consisted of 21 dairy cows. Blood tests were made 

 on all animals on January 1, 1923, of which 10 were positive. Of these 

 reactors 5 had previously aborted. Tlie 10 reactors received intraven- 

 ously 20 cc. of a 2 i)er cent aqiieous solution of collargol January 7, 

 1923. The injection was repeated March 7, and May 7, 1923. One cow 

 showed a c/msiderable reaction from the second injection and all ap- 

 peared to be in distress from the third injection. The most pronounced 



