CHAPTER XIII. 

 RELAPSING FEVER. 



FAMINE FEVER ; SPIRILLUM FEVER ; FIEVRE A 

 RECHUTES ; RUCKFALLSFIEBER. 



AN acute infective fever characterized by the presence 

 of spirilla in the blood and by the common occurrence 

 of relapses. Relapsing fever was formerly common in 

 the British Isles, especially in Ireland, where the associa- 

 tion of its attacks with famine gave it the name of 

 " famine fever." Epidemics, also associated with scarcity, 

 have occurred in several countries of Northern Europe, 

 most commonly in Russia, where there have been recent 

 outbreaks. There was also an outbreak in Austria in 

 1903. In its epidemic form the disease is now most 

 common in India, more particularly in the Bombay 

 Presidency. Outbreaks have also occurred in recent 

 years in Northern China and in Egypt, and cases have 

 been met with in various parts of the world, including 

 Mexico, New York, Cuba, London, Northern Africa, the 

 Sudan, Palestine, Hong Kong, and the Philippines. 



The disease is probably much more common than is 

 supposed, for without systematic examination of the blood 

 isolated cases are almost certain to escape recognition. 

 With such examination it would probably be recognized 

 at any large seaport among the crews of vessels arriving 

 from the Tropics. 



Incubation. The most common duration of the incuba- 

 tion period of relapsing fever is two to five days. The 

 extremes which have been noted are twelve hours and 

 eight days. 



The course of an attack of relapsing fever is commonly 

 as follows : 



