440 



Tetanut 



stances in mixed cultures, and Faber, (1890) in pure cultures. Finally 

 Behring & Kitasato (1892) worked out an cft'ective method of immuniza- 

 tion against the disease, while Vaillard and Vincent, Rouget and Roux, 

 and Tiberti and Tarozzi furnished important contributions on the patho- 

 genicity of the disease. 



Occurrence. Tetanus, a rare disease in the more northern 

 countries, occurs much more frequently in tropical regions and 

 sometimes attains an enzootic character among both man and 

 beast. In the temperate zone, as in Europe, the disease is 

 considered as sporadic and here cases occur in some regions 

 in rapid succession during the spring and fall. Considerable 

 loss occurs usually in horses, sometimes in sheep, Avhile other 

 species of animals as a rule are much less commonly affected. 

 More recently, since greater attention has been giyen to the 

 cleanliness of the wounds, a decrease in the number of cases 

 has been observed. 



In the Prussian army during the years 1899 to 1908, in an average 

 of 87.000 horses, 42 to 64 (average of 52) were attacked annually with 

 tetanus, while in the French army during 1899 and 1900, 98 and 94 

 cases respectively, were reported. — In Hungary the disease appears 

 to be more common in the southern regions, and in certain communities 

 it causes considerable losses, especially after castrations. — The disease 

 appears to occur more frequently in the centers and the outskirts of 

 large cities, and during certain years or seasons. 



It is much more common and widely distributed in warmer countries, and 

 occurs frequently in hors-es, especially after castration, in San Domingo, in the 

 Antilles, Algeria and Egj^jt. 



Etiology. The haciUus tetani Nicolaier, is a straight, 

 slender rod (Fig. 67) possessing feeble motility, and propagates 



Fig. 67. Bacillus tetani iiith 



flagella. Two-day old agar 



culture. 



Fig. 68. Bacillus tetani with spores 

 in various stages of development. Four- 

 day-old agar culture. Carbol-fuchsin 

 staining. 



by fission and also by spore formation. The spore is spherical, 

 with a diameter about twice as long as the thickness of the 

 bacillus, and is situated at one pole of the rod, thus giving 



