ENDEMIC INDEX IN MALARIA 8l 



system of artificial irrigation, are not permissible in the 

 vicinity of a station. 



In all procedures for the reduction in the amount of 

 malaria it must be remembered that partial measures are 

 of value and will result in a diminution in the amount 

 of malaria, but that the more complete the methods are 

 the more successful they will be. The exact measures 

 adopted require an exact knowledge of the local con- 

 ditions and of the normal and exceptional breeding-places 

 of the local dangerous species of anophelines. 



The exact method or combination of methods best 

 suited for each set of conditions will vary according to 

 circumstances, and it may be cheaper to use all measures 

 partially than to carry out thoroughly any single one, and 

 the combination may be fairly effective. 



Estimation of the prevalence of malaria in any place 

 is important, as on the variations in this prevalence the 

 test of the success or otherwise of anti-malarial measures 

 must be judged, and the justification for the cost of 

 the works and the advisability of European occupation 

 determined. 



There are few diseases which affect the working strength 

 of labour gangs so much as malaria. Attacks of the 

 disease in persons once infected are frequent, debility 

 results, and much sick leave is required, so much so that 

 a double staff of Europeans has to be provided. . The 

 mortality is high, though relatively not so high as the 

 morbidity. Amongst natives, the infantile mortality is 

 very high in any place where malaria is prevalent. 



The usual term used to indicate the prevalence of 

 malaria is endemic index. No satisfactory single word 

 has been devised. The determination of the endemic 

 index may be made in many ways : 



(A) Determination of the proportion of the inhabitants 

 infected with the parasites. 



This requires the division into age groups, as in 

 malaria immunity is slowly acquired by repeated attacks. 

 Examinaion of the blood of adults, therefore, in a 

 6 



