RELAPSING FEVER ORGANISM 243 



It does not require any intermediate host for transmission as 

 do the recognized animal parasites of malaria and filariasis, etc. 



Treponema pertenue is the organismal cause of Frambcesia 

 or Yaws, a cutaneous and general infection of the tropics similar 

 to syphilis. It is about the size and shape of the syphilis spiro- 

 chete but is distributed differently in the human lesions, being 

 more in the outer skin and less in the vicinity of blood-vessels. 

 It has not been cultivated. 



Spirochaeta nodosa (Huebner) or icterohemorrhagica (Inada) 

 is believed to be the cause of Weil's disease. The spiral, a tiny 

 organism about 5 micra long is found in the blood, liver and 

 kidneys. It is transmissible to guinea pigs. Rats are supposed 

 to be the means of transfer since several varieties probably 

 harbor the parasite. Excretion of the organism takes place via 

 the kidneys. Spirocheticidal substances occur in the blood in a 

 favorably progressing attack. 



Spirochseta morsus muris and Sp. muris ratti are supposed 

 to be the cause of rat bite fever. These organisms, resembling 

 but grosser than the Treponema pallidum, enter with a rat bite 

 and can be found in swollen drainage lymph nodes. 



RELAPSING FEVER ORGANISM 



European Relapsing Fever. Caused by Treponema of Spiro- 

 chseta obermeieri. 



African Relapsing Fever. Caused by Trep. or Sp. duttoni, 

 transmitted by tick Ornithodorus moubata. 



American Relapsing Fever. Caused by Trep. or Sp. Novii. 



Bombay Relapsing Fever. Caused by Trep. or Sp. carteri. 

 The transmission of the first, third and fourth, while not definitely 

 known, is probably by a louse; ticks may also be responsible. 



Morphology. They have lately been cultivated and retain 

 somewhat of their virulence for monkeys and rodents. They are 

 elongated, flexible, corkscrew-like, serpentine and vibratory in 



