RAT-BITE FEVER 529 



rectum. They also showed that infection could take place through 

 the apparently intaqt skin, and found that this occurred with 

 comparative rapidity, as the application of an antiseptic five 

 minutes after the infective material did not prevent infection. 



A highly important point with regard to the epidemiology of 

 the disease is the common presence of the spirochsete in both 

 house and field rats without any apparent disturbance of health. 

 This has been established now with regard to rats in Japan, in 

 the trenches at the front, and also in America ; and it has been 

 found that the proportion of infected rats is a high one, some- 

 times over 30 per cent. In these animals the organisms are 

 practically confined to the kidneys, and we have here a resem- 

 blance to what is found in the human infection, at a later stage 

 when immune-substances are present in the blood. The spiro- 

 chetes are passed in large number in the urine of the infected 

 animals, and in this way contamination of the soil and various 

 articles is brought about. The spirochetes obtained from rats 

 are found to vary considerably in virulence. 



Rat-bite- Fever. 



More than one form of infection may be produced by the bite 

 of rats. In the form which is commonest in Japan, Futaki and his 

 associates in 1915 found a spirochsete in the skin lesion and in the 

 lymph-glands. Their results have been confirmed by other Japanese 

 workers, and the organism, now called the spirochrete morsus murium, 

 has been established as the cause of the infection. The clinical symptoms 

 are inflammation of the bitten parts, paroxysms of fever of the relapsing 

 type, swelling of the lymph glands, and eruption of the skin, all oc- 

 curring after an incubation period usually of ten to twenty- two days, or 

 longer. The spirochsete, which also occurs in the blood as well as locally, 

 is somewhat short, measuring 2-5 fi, and has a few steep and fairly regular 

 curves of 1 p. each ; it is, however, distinctly thicker than the sp. pallida. 

 It has a distinct and fairly long flagellum at each end, and it is actively 

 motile, the movements being very rapid, like those of a vibrio, and dis- 

 tinguishing it from other pathogenic spirochaates. It has been cultivated 

 outside the body and has been proved to be virulent to mice, rats, and 

 other animals. It has been found in rats in the natural condition, in 

 3 per cent, of house rats, and the disease has been produced in the 

 guinea-pig by allowing a rat infected with the spirochsete to bite it. The 

 infection has been shown to be very amenable to treatment by salvarsa'n, 

 and the blood of a convalescent patient has been found to possess 

 protective properties. 



It is of interest to note, however, that Schottmiiller obtained a strepto- 

 thrix' by culture from the blood in a case of rat-bite fever, and Blake has 

 found the same organism both in the blood and in the cardiac vegetations 

 in another case. Further, Douglas, Colebrook, and Fleming have recently 

 published a case in which the infection was due to a streptococcus. It is 

 thus clear that definition in the nomenclature is required. 



34 



