BEHAVIOR OF BACTERIOPHAGE IN EPIDEMICS 499 



is solely due to the fact that these animals are present in but small 

 numbers in the regions where barbone rages; regions which are extremely- 

 humid and admirably adapted to the buffalo, a semi-aquatic animal. 

 The rare cattle found sometimes in such regions contract the disease and 

 die like the buffalo, after having presented identical syinptoms. 



The effect of low places and swamps on the contagion has been 

 from time immemorial recognized by the natives. When it is possible, 

 as soon as a case of barbone is detected in a neighborhood, they hasten to 

 collect their animals and remove them to a more elevated region. It is 

 known, moreover, that the organisms of the Pasteurella group remain 

 virulent for a very long time in the mud of the marshes and in the slime 

 of the streams. 



Role of the bacteriophage in the disease 



In Cochin-China barbone is always present in sporadic form causing 

 each year numerous small epizootics which remain localized in individual 

 villages. A localized epidemic observed in Long Huu in the Province of 

 Gocong may serve as an example. 



From May 5 to 13, 1920, seventeen buffaloes died: on May 5, one; 

 May 7, three; May 8, two; May 9, one; May 10, two; May 11, four; 

 May 12, three; and May 13, one. Then the epizootic stopped and not a 

 single case was detected during the next six months. 



Specimens of the feces of four of these animals were collected, either 

 before death or from the cadaver. None contained a bacteriophage 

 active for the bacterium of barbone. On May 13 specimens of feces 

 were collected from healthy animals, as follows : 



First. From a buffalo in a stable where two animals had died, one 

 on May 12, the other on May 13. 



Second. From three buffaloes in a stable where one had died on 

 May 5. 



Third. From two buffaloes in a stable where two had died, one on 

 May 8, the other on May 11. 



Fourth. From four buffaloes in a stable which had not been invaded. 



Fifth. From one buffalo, living alone in a stable located at a dis- 

 tance of about five kilometers from the village of Long Huu. 



Sixth. From eight buffaloes in the surrounding villages, from eleven 

 to nineteen kilometers distant. 



Of all the specimens, those in the first, second, third and fourth 

 groups gave a bacteriophage of weak or average activity (+ or ++) 

 for the bacterium of barbone. An active bacteriophage was not found 

 in the specimens from groups 5 and 6. 



