Occurrence, Etiology. 681 



In Austria the number of cases ranged from 400 to 550 from 1891 to 1900. 

 In 1896 there were 647, and in 1898 there were 1,043 ca-ses (among these were 519 

 horses slaughtered for food in Lower Austria). In 190S the weekly average of 

 infected parishes ranged from 7 to 41, most of the infected parishes being in the 

 provinces of Galieia, Lower Austria and the Kingdom of Bohemia, while Upper 

 Austria, Tyrol and Yorarlberg were free from outbreaks. 



Eussia is at present badly infested; about 4% of all horses are infecteil with 

 the disease, and over 10,000 horses are officially destroyed every year. In 1900 the 

 loss in the Cherson Government reached 2,000, in Tauris 2,067, in St. Petersburg 

 alone 469, in Odessa 722 glandered horses (Samborski). In 1908, 15,693 cases 

 were reported in 7,828 parishes. 



In Hungary the annual number of cases has for years ranged between 700 

 and 950, although in 1895 the number reached 1,177, and in 1898, 1,683 cases. In 

 1908, 946 cases were reported from 261 parishes, mostly based upon the results of 

 mallein tests. The largest number of cases were reported from the southern dis- 

 tricts. 



The following official figures are available for 1908 : Belgium 18, Netherlands 

 26, Italy 535, Eoumania 200, Switzerland 4 cases, while Denmark reported 21 

 infected stables, Bulgaria 132, and Norway and Sweden are free from disease. 



The disease is prevalent also in Asia (India, Japan), in Africa (Algiers, 

 Egypt and South Africa; in the latter country only since recent times), as well as 

 in America (United States, especially in the northwestern States). Australia has 

 thus far remained free from the disease. 



Etiology. The Bacillus mallei is 

 a straight, or slightly bent, slender, 

 immotile, non-sporulating rod with 

 rounded or somewhat pointed ends ; 

 its length is about 1/3 to 2/3 of the 

 diameter of a red corpuscle (2-5 i^ 

 long, 0.3-0.5 ^ in diameter; Fig. 13). 

 In tissues the bacilli are usually 

 found in pairs or in larger sheaf-like 

 bundles, while in artificial cultures 

 they may occasionally form filaments 

 or branched threads. (Marx and ,^^-^^ ^^^^ ^ 



Conradl therefore claSSlty them as stained with methylene blue . 



Streptothrixes.) 



Staining. The bacilli stain slightly with aqueous anilin dyes more 

 readily in staining solutions containing caustic potash or carbolic acid, 

 often imperfectly or irregularly in diseased organs. They are de- 

 colorized by Weigert's or Grain's methods. In bacilli from cultures, 

 stained with carbolfuchsin or methylene blue, we may observe one or 

 two more intensely stained granules or bodies (usually at the ends). 



Cultivation. The bacillus of glanders is an obligate parasite; on 

 artificial media it thrives only at temperatures a})ove 20° C, best at 

 body temperature; between 41.5° and 43° C. its growth is very slow 

 and ceases above 45° C. Neutral or slightly acid, as well as glycerin 

 media are best adapted for its growth. The cultures have a peculiar 

 smeary or slimy consistency and thrive only in the presence of oxygen. 

 On potatoes there appear, on the second day, small honeydrop-like, 

 transparent colonies that subsequently coalesce into a fawn or chocolate- 

 colored, thick, shiny, ropy mass, while the culture medium in the ad- 

 jacent area becomes bluish or greenish in color (Fig. 114). On agar 

 there develop gray, transparent, slimy, ropy colonies with smooth out- 

 lines, subseriuently becoming dark gray and more tenacious in con- 

 sistency. On coagulated blood serum pale yellow, transparent colonies 



