TYPHUS FEVER 559 



ordinary sugars and alcohols. Growth appears to take place in 

 litmus milk reenforced with bits of sterile tissue, but no visible change 

 in the medium can be detected. Cultivations can be readily made 

 from Berkefeld filtrates of ascitic fluid growths, thus showing that 

 the organisms, or at least some of them, are filterable. Cultures of 

 the organism were shown to cause the typical disease with characteristic 

 lesions in monkeys. 



Flexner, Noguchi and Amoss 1 have shown that cultures of the 

 organism may retain their virulence for monkeys at least a year, and 

 Flexner, Clark and Amoss 2 have shown that the virus retains its patho- 

 genicity in 50 per cent, glycerin for eleven months; in 0.5 phenol for 

 five days, and frozen at 2 to 4 C. for at least six weeks. Amoss 3 

 has improved the technic for cultivating the virus of epidemic polio- 

 myelitis. 



Pieces of brain from infected animals are incubated in the kidney- 

 ascitic fluid of Noguchi for about two weeks, then crushed carefully 

 and reincubated for three days longer. The globoid bodies appear 

 to multiply in the brain tissue and their subsequent recognition and 

 cultivation is rendered more certain. Stained sections of such brain 

 tissues show increased numbers of organisms. 



Immunity. One attack appears to confer immunity in man, but the 

 evidence is not conclusive. Flexner and Lewis 4 have been unsuccessful 

 in reinfecting monkeys which have recovered from a typical infection 

 and they lean toward the view that one attack confers immunity in 

 these animals. 



The characteristic disease has not been produced in experimental 

 animals other than primates. 



Typhus Fever (Tabardillo, Brill's Disease). Typhus fever is an 

 acute, febrile disease of man characterized by an incubation period 

 varying from four to five days to twelve days, an acutely developing 

 febrile reaction which persists for about two weeks, falling by crisis, 

 or rapid lysis, and an extensive erythematous eruption, maculo- 

 papular in character, which appears usually within three to four 

 days after the onset, and persists for about ten to fourteen days. 

 The disease pathologically is to be regarded as a hemorrhagic septi- 

 cemia; the lesions postmortem are not distinctive, and the changes 

 in the organs are those produced by an intense febrile reaction. The 



1 Jour. Exp. Med., 1915, xxi, 91. 2 Ibid., 1914, xix, 207. 



3 Ibid., 1914, xix, 212. * Loc. cit. 



