DISEASES CAUSED BY SPIROCH^TES 867 



subjecting the animals to the bites of the infected insects. For the 

 European variety of the disease no such intermediate host has as yet 

 been demonstrated with absolute certainty. It is known, however, 

 that the organism can live in the bodies of bed bugs and it has also 

 been suggested that lice may be the carriers. Lice also are regarded 

 as the transmitting agent of a similar relapsing fever prevalent in 

 North Africa caused by the Spiroschaudinnia, berberi. 



Immunity. It has long been a well-known fact that recovery 

 from an attack of relapsing fever usually results in a more or less 

 definite immunity. The blood of human beings, monkeys, and rats 

 which have recovered from an attack of this disease show definite 

 and specific bactericidal and agglutinating substances, and Novy 

 and Knapp have demonstrated that the blood serum of such animals 

 may be used to confer passive immunity upon others. 



VINCENT'S ANGINA 



The condition known as Vincent's angina consists of an inflam- 

 matory lesion in the mouth, pharynx, or throat, situated most fre- 

 quently upon the tonsils. The disease usually begins as an acute 

 stomatitis, pharyngitis, or tonsillitis, which soon leads to the forma- 

 tion of a pseudo-membrane, which, at this stage, has a great deal 

 of resemblance to that caused by the diphtheria bacillus. At later 

 stages of the disease there may be distinct ulceration, the ulcers 

 having a well-defined margin and "punched-out" appearance, so 

 that clinically they have often been erroneously diagnosed as 

 syphilis. Apart from the localized pain, the disease is usually mild, 

 but occasionally moderate fever and systemic disturbances have 

 been observed. Unlike diphtheria and syphilis, this peculiar form 

 of angina usually yields, without difficulty, to local treatment. 



The nature of lesions of this peculiar kind was not clear until 

 Plaut, 51 Vincent, 52 and others reported uniform bacteriological find- 

 ings in cases of this description. These observers have been able 

 to demonstrate in smears from the lesions a spindle-shaped or fusi- 

 form bacillus, together with which there is usually found a spirillum 

 not unlike the spirillum of relapsing fever. The two microorganisms 

 are almost always found together in tliis form of disease and were 



r>l Plaul, IViit. mod. Wocli., xlix, LS04. 



"- rincait, Ann. do 1'mst. Pasteur, 389(5, and Bull, et mem. do la sue. mod. 

 des hop. de P., 1898. 



