THE TOLL OF THE MOSQUITO 5 



DISTRIBUTION OF MALARIA 



Trask 1 sums up the distribution of malaria in the United 

 States as follows : 



"In the territory extending from the Gulf of Mexico to a line north of 

 the Ohio River and from the Atlantic seaboard to and into the eastern 

 part of Kansas, Oklahoma and Texas, few, if any, localities are entirely 

 free from malaria. In most of the lowlands it is very prevalent; in the 

 mountains and better drained areas less prevalent. 



Fig. 9. — Endemic areas of malaria in the United States. Shaded portions of 

 map show endemic areas. Shaded circles represent localities in which cases of 

 malaria occur and in which the disease is probably endemic. (After Trask.) 



' The disease is also endemic in southeastern Xew York and parts 

 of Connecticut, Rhode Island and Massachusetts, and in California 

 in the Sacramento and San Joaquin valleys. 



"There is probably no state in the Union in which the disease is not 

 present and in which it is not spread by mosquitoes grown locally. 



"The disease constitutes one of the big national health problems. 

 It is also an economic problem of importance." 



Elsewhere, malaria is found in nearly every country, its 

 incidence increasing, as a rule, with proximity to the Equator. 



i— 



'"Malaria, A Public Health and Economic Problem in the United 

 States," U. S. Public Health Service, 1917. 



