Proceedings of Eighth Annual Meeting 87 



tive, but a new form of record cards has been adopted by the Inter- 

 national Health Board which will virtually establish a continuous 

 individual health record of every person on the plantation. The 

 local incidence of malaria infection is unquestionably very high but 

 no data exists at the present time which would justify positive asser- 

 tions. Published statements to the effect that malaria has been very 

 materially reduced in Madison Parish, La., during the last few 

 years are not in accordance with the facts. It would not seem advis- 

 able to utilize the earlier statistical investigations, for there are 

 reasons for believing that the new records will yield decidedly more 

 trustworthy results, both as to blood infection and actual disease 

 occurrence. 



Nor would it seem advisable for the time being to discuss the 

 correlation temperature and rainfall data as derived from the Vicks- 

 burg station, although it may be said in passing that there does not 

 seem to be the close relation between rainfall and malaria occurrence 

 in the river belt of Louisiana and Mississippi as observed in coun- 

 tries decidedly more malarious. 



In the absence of really trustworthy malaria statistics for Louis- 

 iana the admirable morbidity data for Mississippi have been util- 

 ized for the present purpose. These data extend over a period of 

 seven years and, as far as known, they are the only comprehensive 

 malaria morbidity statistics for any section of the world. They show 

 that the incidence of the disease has slightly diminished during the 

 last three years compared with the preceding three years, although 

 the average rainfall was higher during the latter than during the 

 earlier period. The Mississippi data also show that the monthly 

 variation in the frequency of the disease is practically the same for 

 the two races, while the recording incidence of the disease is some- 

 what higher among the whites than among the colored. Comparing 

 the 1915-17 rate with that for 1918-20, the white malaria morbidity 

 rate diminished from 93.1 per 1,000 of population to 66.9, while the 

 colored rate diminished from 77.6 to 59.5. This reduction, while 

 not as gratifying as anticipated, is nevertheless an indication of the 

 effectiveness of preventive measures, particularly in the Yazoo 

 Deka, where the disease continues to prevail to a very considerable 

 extent. It may be said in passing that the malaria mortality rate per 

 100,000 of population for the Delta counties of Mississippi was 126.8 

 for the period 1915-17 against 91.0 for the period 1918-19, indica- 

 tive of a reduction equivalent to 28.2 per cent. I may add to the 

 foregoing the statement that in the intensely malarious counties of 



