PERTUSSIS. 753 



ing cough as similar to that of the streptococcus 

 to scarlet fever i. e., a very important compli- 

 cating organism. 



Davis finds still further reason for doubting its 

 specific relationship to whooping cough from the 

 fact that it was found frequently in measles, acute 

 influenza, epidemic meningitis, bronchitis, vari- 

 cella and in normal throats. 



In 1906 Bordet and Gengou isolated a bacillus 

 from cases of whooping cough and gave the fol- 

 lowing reasons for believing that it was the spe- 

 cific etiologic factor in this disease : 1. The organ- 

 ism is found in overwhelming numbers during the 

 early course of the disease and in almost pure cul- 

 ture. 2. The bacilli as antigen give a comple- 

 ment-fixation reaction with the serum of pertussis 

 patients and this reaction does not occur with 

 other bacteria associated with the disease. 



The organism is a short, polar-staining ovoid 

 resembling the influenza bacillus but slightly lar- 

 ger. Bordet and Gengou grew the organisms on a 

 culture medium made up of a glycerin-potatoe- 

 blood-agar mixture. On this medium the organ- 

 ism grows in the form of a delicate film made up 

 of very small colonies and changes the medium to 

 a dark brownish color. 



Wollstein was able to confirm the finding of 

 the bacillus in the early stages of pertussis, but 

 failed to obtain the complement-deviation reac- 

 tion. Agglutination was very irregular and no 

 immune opsonins were found. The etiologic rela- 

 tionship of the organism to whooping cough is at 

 present uncertain. 



The organism is disseminated extensively by 

 coughing, and the same is probably true of the es- 



