ASIATIC CHOLERA AND THE CHOLERA ORGANISM 837 



Cholera Toxin. The absence of the cholera spirilla from the 

 internal organs of fatal cases, in spite of the severe general symp- 

 toms of the disease, points distinctly to the existence of a strong 

 poison produced in the intestine by the microorganisms and absorbed 

 by the patient. It was in this sense, indeed, that Koch first inter- 

 preted the clinical picture of cholera. Numerous investigations into 

 the nature of these toxins have been made, the earlier ones defective 

 in that definite identification of the cultures used for experimentation 

 were not carried out. 



Pfeiffer, 6 in 1892, was able to show that filtrates of young bouillon 

 cultures of cholera spirilla were but slightly toxic, whereas the dead 

 bodies of carefully killed agar cultures were fatal to guinea-pigs 

 even in small quantities. In consequence, he regarded the 

 cholera poison as consisting chiefly of an endotoxin. 7 The opinion 

 as to the endotoxic nature of the cholera poison is not, however, 

 shared by all workers. Metchnikoff, Roux, and Salimbeni, 8 in 1896, 

 succeeded in producing death in guinea-pigs by introduction into 

 their peritoneal cavities of cholera cultures enclosed in celloidin 

 sacs. Brau and Denier, 9 and, more recently, Kraus, 10 claim that 

 they have succeeded not only in demonstrating a soluble toxin in 

 alkaline broth cultures of cholera spirilla, but in producing true 

 antitoxins by immunization with such cultures. It appears, there- 

 fore, that the poisonous action of the cholera organisms may depend 

 both upon the formation of true secretory toxins and upon endo- 

 toxins. Which of these is paramount in the production of the 

 disease can not be at present definitely stated. In favor of the 

 great importance of the endotoxic elements is the failure, thus far, 

 to obtain successful therapeutic results with supposedly antitoxic 

 sera. 



Epidemiology. Cholera is essentially a disease of man. Endemic 

 in India and other Eastern countries, it has from time to time 

 epidemically invaded large territories of Europe and Asia, not in- 

 frequently assuming pandemic proportions and sweeping over almost 

 the entire earth. Five separate cholera epidemics of appalling mag- 

 nitude occurred during the nineteenth century alone; several of 



6 Pfeiffer, Zeit. f. Hyg., xi, 1892. 



''Pfeiffer und Wassermann, Zeit. f. Hyg., xiv, 1893. 



8 Metchnikoff, Eoux, et Salimbeni, Ann! de Pinst. Pasteur, 1896. 



9 Brau et Denier, Comptes rend, de Pacad. des sci., 1906. 



10 E. Kraus, Cent. f. Bakt., 1906. 



