248 INFECTION AND IMMUNITY 



proper treatment is resorted to ( the administration of 

 quinine). But the infection is very persistent, re- 

 lapses are frequent, and in malarious regions many 

 individuals often suffer for years from chronic mala- 

 rial infection and finally succumb to some chronic or- 

 ganic disease resulting from repeated attacks of fever, 

 or from some acute disease for which a predisposition 

 has been established as a result of continued ill-health 

 and the anaemia which is characteristic of chronic 

 malarial poisoning. The greatest proportional num- 

 ber of deaths from malarial fever, within the limits of 

 the United States, during the census year 1900 oc- 

 curred in the "South Mississippi River belt" (88.8 

 per 1000 deaths from all causes) ; the next greatest in 

 the "South Atlantic Coast region" (61.7) ; the next 

 greatest in the "South-west Central region " (57.9) ; 

 next in the " Gulf Coast region " (47.9) ; next in the 

 "Southern Interior plateau" (43.8). The least mor- 

 tality occurred in the region of the " Great Northern 

 Lakes" (2.2); next in the "North Atlantic Coast 

 region" (2.3); next in the "Central Appalachian 

 region " (2.6) ; next in the " Northeastern hills and 

 plateaus" (2.8); next in the "Pacific Coast region" 



( 2 . 9 ). 



Now that we know the life history of the malarial 

 parasite and the manner by which it gains access to 

 the human body, the proper preventive measures are 



