CHAPTER XVII 



YELLOW FEVER 



WELLOW fever is an infectious disease which has 

 a comparatively restricted geographic range. 

 Occasional epidemics have occurred in North Amer- 

 ica in every one of our seaport cities as far north as 

 Boston and on the Mississippi River as far north 

 as St. Louis, but it has never established itself as 

 an endemic disease within the limits of the United 

 States. The cities of Havana, Vera Cruz, and Rio 

 de Janeiro have been the principal foci of the disease 

 for many years, and from these cities it has been car- 

 ried to the seaports of North and South America 

 and of the West Indies. It has also prevailed for 

 many years on the west coast of Africa, which by 

 some authorities is regarded as the original source of 

 this pestilential malady, while others believe that it 

 already existed in the West Indies at the time of the 

 discovery of these islands. The disease has never 

 reached the east coast of Africa, and is unknown in 



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