TYPHUS FEVER 679 



the epidemic, which is still under cultivation. However, these organisms were 

 found so rarely, in spite of a considerable number of blood cultures that were 

 taken, and the necessity of working with unsterilized ascitic fluid under rela- 

 tively primitive conditions, forced the conclusion upon them that these isolated 

 findings, though pointing somewhat in favor of Plotz's organism, did not es- 

 tablish definite proof. However, of the many blood cultures taken, the smaller 

 number were taken from fresh cases, most of the ascitic fluid used did not 

 come up to the specifications of Plotz, and there is no doubt about the fact 

 that the organism described by Plotz is not one that is very easily cultivated 

 unless rich ascitic fluid is available. 



The fact that the Plotz organism has been cultivated from guinea- 

 pigs and monkeys experimentally inoculated is further evidence in favor 

 of this bacillus. 



Petruschky 1 has recently cultivated a similar but aerobic bacillus from 

 sputum in typhus cases and Arnheim 2 has aerobically cultivated an organism 

 which in appearance and staining properties is not unlike the Plotz bacillus. 

 Arnheim obtained his organism from six cases, on ascitic agar plates, on which 

 on the first cultures there appeared a growth hardly visible to the naked eye 

 and which in transplants continued to grow very delicately. He states his 

 organism is not unlike that of Petruschky and he obtained it out of the blood, 

 the sputum and the urine of typhus cases. 



There appears at the present writing to be much evidence in favor 

 of the bacillus of Plotz as the causative agent, the only objection to its 

 final acceptance being that, despite the fact that a great many workers 

 have been studying this disease during the last few years, the micro- 

 organisms which have been described have not been similar one with 

 the other, and the fact that the Plotz organism seems to lose its viru- 

 lence almost immediately upon artificial cultivation. Also according 

 to Anderson, active immunization with the Plotz bacillus does not 

 render guinea-pigs refractory to virus inoculation. All these things breed 

 conservatism. However, with a relatively simple method and sufficient 

 typhus material, the question of the Plotz bacillus should soon be defi- 

 nitely settled. 



The transmission of typhus, as shown by Nicolle, Ricketts and 

 Wilder, and Anderson and Goldberger seems to be mainly through the 

 agency of the louse, the body louse (pediculus vestimenti) pretty 

 surely, the head louse (pediculus capitis) possibly, the pubic louse 

 probably not. So far, no evidence has been obtained that the disease 



1 Petruschky, Centralbk. "f . Bakt., Ixxv, 1915, p. 497. 



2 Arnheim, D. Med. Woch., 36, 1916, p. 1060. 



