510 PATHOGENIC MICROORGANISMS 



and the Bacillus tuberculosis, are the investigations upon the action 

 of tuberculin upon leprous patients. When tuberculin is adminis- 

 tered to lepers, a febrile reaction occurs usually twenty-four or more 

 hours after the administration. The fever differs from that produced 

 by the use of the same substance in tuberculous patients in that it is of 

 late occurrence and lasts considerably longer. "At the same time, there 

 may be marked redness and tenderness of the nodules. In isolated 

 cases, Babes 1 has noticed alarmingly high and prolonged fever together 

 with systemic symptoms such as nausea, headache, and even uncon- 

 sciousness, following the injection of tuberculin. The same writer 

 claims to have extracted from the organs of lepers, which contained 

 enormous numbers of bacilli, substances which showed an action similar 

 to that of the tuberculin. 



RAT LEPROSY 



Stefansky 2 first observed this disease among rats in Odessa, and 

 since then it has been observed in Berlin (Rabinovitsch 3 ), -in London 

 (Dean 4 ), in New South Wales (Tidswell 5 ), and in San Francisco 

 (Wherry 6 and McCoy 7 ). The disease occurs spontaneously among 

 house rats and is characterized by subcutaneous induration, swelling of 

 lymph nodes, with, later, falling out of the hair, emaciation, and some- 

 times ulceration. Its course is protracted and rats may live with it 

 for six months or a year. When a rat suffering from this disease is dis- 

 sected there is usually found, under the skin of the abdomen or flank, a 

 thickened area which has the appearance of adipose tissue except that 

 it is more nodular and gray and less shiny than fat. It is so like fat, 

 however, that it is often possible to overlook it as evidence of disease 

 by one unfamiliar with the condition. In this area acid-fast bacilli 

 looking like the Bacillus leprse are found in large numbers. These 

 bacilli are also found in the lymph nodes and sometimes in small nodules 

 which appear in the liver and lung. 



1 Babes, in Kolle und Wassermann, "Handbuch," etc., Erst. Ergilnz. Bd., 1907. 



2 Stefansky, Centralbl. f. Bakt., xxxiii, 481. 



3 Rabinovitsch, Centralbl. f . Bakt., xxxiii, 577. 



4 Dean, Centralbl. f. Bakt., xxxiv, 222; Jour. Hyg., xcix. 



6 Tidswell, cited by Brinkerhoff in "The Rat and Its Relation to Public Health," 

 Treas. Dept:, Wash., 1910. 



6 Wherry, J. A. M. A., June 6, 1908, p. 1903; Jour. Inf. Dis., dvii, Rep. U. S. 

 P. H., and M. H. S., xxiii, 1841. 



''McCoy, Rep. U. S. P. H. and M. H. S., xxiii, 981; Abstr. in J. A. M. A., 

 Aug. 22, 1908, 690. 



