1358 



RAT-BITE AND CAT-BITE FEVERS 



Human serum shows definite spirochaetolytic and spirochaeticidal 

 properties eleven months after the onset of the disease. 



These researches make it probable that S. morsusmuris is the 

 setiological agent of the disease. 



Naturally infected guinea-pigs have been seen by Niowaka, 

 Yoshizawa, and Mumento, who have shown that the disease can 

 be spread from guinea-pig to guinea-pig by subcutaneous injections 

 of the saliva or by bites of infected guinea-pigs. The organisms 

 may possibly live in the salivary glands of rats. The men mostly 

 infected are agriculturists and sailors, but it has been seen in soldiers 

 in the trenches and persons living in ordinary houses. 



Row regards the strain found by him in Bombay as being different from 

 the Japanese strain. 



Pathology. — ^At first the reaction against the organism is weak, 

 but later immune bodies specific against the spirochsetes are found. 



Morbid Anatomy. — Only four post-mortem examinations are 

 on record — ^viz., those by Miura and Toriyama in 1897, by Blake in 

 1916, and two by Kaneko and Okuda in 1917. 



In the first the conditions were increase of the cerebro-spinal fluid, 

 hypersemia of the meninges, inflammatory oedema of the lungs, and 

 cloudy swelling of the liver. 



In the second there were acute ulcerative endocarditis, subacute 

 myocarditis, interstitial hepatitis, glomerular and interstitial 

 nephritis, infarcts in the spleen and kidney, haemorrhages and 

 oedema of the lungs. Microscopically, degeneration and necrosis 

 of the cardiac muscles; polymorphonuclear infiltration into the liver 

 and into the shrunken kidney, but many of the changes may have 

 been due to the nocardia found by Blake. 



In the third case there were no marked pathological changes, 

 except parenchymatous changes in the organs, such as hyperaemia, 

 swelling, and degeneration of the tubular epithehum of the kidney. 

 There is degeneration, necrosis, and destruction of the liver cells, 

 particularly in the centre of the lobule, with hypersemia and fatty 

 degeneration of the peripher3^ of the lobule, with also haemor- 

 rhages. No abnormalities in the spleen, lymphatic glands, or 

 bone-marrow, except that the local lymph glands show a hyperplasia 

 of the parenchymatous cells. Catarrhal changes are seen in the 

 mucosa of the stomach, as well as catarrhal cystitis, congestion of 

 the lungs and meninges, and degeneration of the muscles of the leg 

 and nerve cells of the brain cortex and spinal cord. 



The skin near the bite shows hypersemia, oedema, and polymorpho- 

 nuclear infiltration into the corium and subcutaneous tissue, but no 

 changes in the epidermis. 



The changes found in experimental animals agree with those seen 

 in man. 



Symptomatology- — Incubation. — ^The incubation period varies 

 from seven to twenty-two days, but the average is twelve days. 

 During this period the wound caused by the bite heals. 



The Attack. — ^The onset is sudden. The site of the bite, which, in 



