302 BACTERIA AND DISEASE 



j 



concerned with the alimentary tract. Water, milk, shell-fish, fried 

 fish, ice-cream, watercress, etc., have all been proved to be the 

 vehicle of infection in spreading the disease. Personal contact may 

 and does operate in spreading infection, and by this means food 

 also may become contaminated. Flies are held to have acted as 

 carrying agents in the Spanish -American War of 1898 and the 

 Boer War of 1900-1902. Oorfield records some dozen outbreaks of 

 typhoid fever due to general insanitary conditions, 60 outbreaks 

 to infected water, and a large number to minor channels.* The 

 writer has collected 160 records of milk-borne outbreaks of the 

 disease.f 



In 1880-81 Eberth announced the discovery of the typhoid 

 bacillus in cases of clinical enteric fever. In 1884 it was first 

 cultivated outside the body by G-affky. Since then other organisms 

 have been held responsible for the causation of enteric (or typhoid) 

 fever. In 1885 the B. coli communis was recognised, and it has 

 been a matter of some debate among bacteriologists as to how far 

 these two organisms are the same species, and interchangeable. 

 There is evidence on both sides of the question, but bacteriologists 

 generally regard the Eberth-Gaffky bacillus as the specific cause of 

 typhoid fever, though complete proof is still wanting. 



Under the microscope the bacilli appear as rods, 2-4 yu long, 

 5 /x broad, having round ends. Sometimes threads are observable, 

 being 10 /x in length. In the field of the microscope the bacilli 

 differ in length from each other, but are approximately of the same 

 thickness. Bound and oval cells constantly occur even in pure 

 culture, and many of these shorter forms of typhoid appear to be 

 identical in morphology with some of the many forms of B. coli. 

 There are no .spores. Motility is marked ; indeed, in young culture 

 the typhoid bacillus is the most active pathogenic germ we know. 

 The small forms move about with extreme rapidity; the longer 

 forms move in a vermicular manner. Its powers of motility are 

 due to some five to twenty flagella of varying length, some of them 

 being much longer than the bacillus itself. The flagella are both 

 terminal and lateral, and are elastic and wavy. 



The organism may be isolated from the ulcerated Peyer's patches 

 in the intestine, from the spleen, the mesenteric glands, and the 

 urine. Owing to the mixture of bacteria found elsewhere, it is 

 generally most readily isolated from the spleen. The whole spleen 

 is removed, and a portion of its capsule seared with a hot iron to 

 destroy superficial organisms. With a sterilised knife a small cut 

 is made into the substance of the organ, and by means of a sterilised 

 platinum wire a little of the pulp is removed and traced over the 



* The Milroy Lectures on Typhoid Fever, 1902. 



j Bacteriology of Milk, 1903 (Swithinbank and Newman). 



