INFECTIOUS DISEASES OF MICE 421 



erythrocytes. The organisms are few in number per red blood cell and 

 appear to be on or possibly in some instances in the cell itself. A few may 

 be found at times free in the plasma, possibly released by destruction of 

 infected erythrocytes. Ordinarily, splenectomized mice show no signs of 

 infection (238, 171), although some animals develop anemia (303, 155, 167). 

 Pathological examination of splenectomized mice reveals little beyond 

 possible hyperplasia of endothelial cells and foci of lymphocytes in the liver 

 (55). Carrier mice may show some degree of splenomegaly which, how- 

 ever, may occur in the absence of infection of this t>pe. The manner of 

 spread in mice has not yet been established. Arthropods may be the 

 vectors since in rats the flea {Hacmatopinus spinulosis) can transmit the 

 infection (64, 331). 



iMixed infections with bartonella and Eperythrozoon coccoides may follow 

 splenectomy (238, 157, 158. 121, 60). Lwoff and Vaucel (157, 158) believe 

 that under these conditions the virulence of the Bartonella may be increased. 



The administration of arsenicals to both rats and mice is effective in 

 eradicating latent bartonellosis or in treating the more acute infection which 

 follows splenectomy. Dosages recommended (34, 122) are approximately 

 12.5 mg. of neosalvarsan or 100 mg. of tryparsamide per 100 grams of body 

 weight. A combination of arsenic and antimony (Bayer's "sdt 386") is 

 stated to be particularly efficacious (122). Sulfanilamide has been found 

 to be unsatisfactory in the rat disease (65). Domagk and Kikuth (55) have 

 emphasized that the effective dose of the chemotherapeutic agent must not 

 injure the reticulo-endothelial system if the results are to be satisfactory. 



The experimental disease. — Numerous attempts have been made to 

 transmit the mouse strain of bartonella to both normal and splenectomized 

 mice free from the disease, with varying degrees of success. In some 

 instances, transmission has failed (185, 121, 60); in others, massive and at 

 times fatal infection with anemia has resulted even in normal mice (156, 

 60). The work of Lw^off, Provost, and Vaucel (156, 303, 158, 155) is of 

 some interest in this regard. A non-splenectomized mouse, inoculated 

 with Trypanosoma cruzi. developed a bartonella infection, which was then 

 transferred successively in normal mice by inoculation of blood, and was 

 ultimately separated from the trypanosome. The trypanosome had been 

 passed through two rats and one dog before inoculation into the mouse. 

 None of the mice was resistant to the bartonella infection. The organisms 

 appeared usually on the second day, increased in number until the fifth or 

 sixth day, and disappeared about the ninth day. Anemia and splenomegaly 

 were the only significant pathological changes reported. No recurrences 



