XXVII. THE BACILLUS OF WHOOPING-COUGH * 



BY DRS. J. BORDET AND O. GENGOU. 



The bacteriology of whooping-cough has been studied to a con- 

 siderable extent during the last twenty years. Many bacteria 

 have been isolated from the sputum and described as the true 

 etiological factor in this disease; we believe, however, that none of 

 these micro-organisms that have been grown by our predecessors 

 is identical with the one we have obtained, which latter organism, 

 on account of the logical proofs that we have been able to find, 

 must be considered as the true parasite that has been sought for. 



The failure of other bacteriologists, as well as our own failures 

 for nearly six years, during which time we have studied whooping- 

 cough, are easily explicable in view of certain circumstances which 

 may be briefly mentioned. 



As every one knows, the success of attempts to isolate an un- 

 known pathogenic agent depends on the presence of a sufficient 

 number of the organisms in the product that is studied and on the 

 fact that these organisms shall not be lost in the midst of innumer- 

 able non-specific bacteria. These conditions of relative abundance 

 and purity of culture of the specific organism are not easily met 

 with in the majority of cases of whooping-cough, except in the 

 beginning. And, what is more, even during this beginning period 

 only that part of the expectoration which comes from the region 

 in which the bacteria are most active should be used ; in other words, 

 the products from the depths of the bronchi expectorated during 

 the periodic accesses of the disease. This exudate during the 

 characteristic " whoop" is white, thick, and rich in leucocytes; 

 it contains the bacilli of whooping-cough in considerable numbers 

 and in favorable cases in almost pure culture. At the same time 

 the child often expectorates a more transparent mucous and sticky 

 secretion which contains less cells and many fewer specific bac- 



* Le microbe de la coqueluche. Annales de 1'Institut Pasteur, vol. 20, 1906, 

 p. 731. 



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