CHAPTER VIII 



MOSQUITOES AND YELLOW FEVER 



ELLOW fever is a disease, principally 

 of seaport towns, from which the United 

 States has suffered more than any other 

 country. It is endemic only in tropical 

 regions but is often carried to subtropical, some- 

 times even to temperate zones where, if the proper 

 mosquitoes exist, it may rage until frost. 



Vera Cruz, Havana, Rio de Janiero, and the 

 west coast of Africa were long regarded as per- 

 manent endemic foci, the disease appearing there 

 in epidemic form from time to time, often spread- 

 ing to other ports in more or less close communi- 

 cation with such places. In the United States the 

 Gulf states have been the greatest sufferers from 

 the disease, although it has spread as far as Balti- 

 more, Philadelphia and Washington, where at rare 

 intervals it was most serious, abating its ravages 

 only when frost came. 



The last severe outbreak occurred in New Or- 

 leans in 1905 when eight thousand cases and nine 



