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Precautions Necessary in Applying the 

 Spleen Test 



I. The Age of the Individuals Examined. — 

 The enlargement of the spleen due to ordinary 

 malarial infection tends to disappear once the 

 individual has ceased to suffer from, malarial 

 infection. In very malarious countries, where 

 each individual, after childhood, has become 

 highly immune, the adult population usually shew 

 no splenic enlargement (Tropical Africa). 



In less malarious regions the adults have not 

 become highly immunized, and a certain number 

 of them will be found with enlarged spleens and 

 malarial infection. The use then of the percent- 

 age of adults with enlarged spleens is not a 

 reliable method of determining the real intensity 

 of malaria. 



In children, the spleen enlargement appears 

 to require a certain time to become apparent, and 

 it takes a certain time to disappear, as the 

 malarial infection disappears with ensuing im- 

 munity. 



In the examination of children for splenic 

 enlargement and the presence of parasites in their 

 blood, we found : — 



(i) In the early ages, one to two years, the 

 number infected is usually in excess of those 

 shewing splenic enlargement. 



(ii) Above two years, the spleen rate is 

 usually somewhat in excess of the parasite rate. 



(iii) Above ten years, the spleen rate is 

 usually considerably in excess of the parasite rate. 



In the use of a spleen census one should then 

 avoid a mixed adult and child count, and children 



