PLANNING MALARIA CONTROL 
289 
geographic distribution and areas of con¬ 
centration. 
In competent hands, splenometry is a 
rapid and inexpensive method of estimat¬ 
ing malariousness. Since details of the 
technique are given in Dr. Elmendorf’s 
paper, they will not be included here. Cer¬ 
tain practical difficulties in applying it on 
a large scale may be mentioned, however. 
To obtain reliable and comparable infor¬ 
mation, spleen palpation should be done by 
well-trained and experienced medical per¬ 
sonnel, desirably by the same individual. 
Thus either the area of reconnaissance is 
restricted to what one person can handle in 
a given season or several individuals must 
be involved. This last is not easily ar¬ 
ranged because experienced splenometrists 
are rare and it is difficult to enlist the in¬ 
terest of the health officer in the procedure. 
His acquaintanceship with malaria sple¬ 
nomegaly is usually restricted to observa¬ 
tions made on patients acutely ill with ma¬ 
laria. Their spleens are enlarged, but the 
increase in bulk is due mainly to conges¬ 
tion. They are soft, doughy, and mobile 
and it is not easy to define their lower mar¬ 
gins by palpation. Thus the physician 
who later becomes a health officer is frankly 
skeptical about the value of splenometry as 
a measure of malariousness. If he can be 
induced to try it on any considerable scale, 
he soon experiences the thrill of finding for 
himself the firm, unmistakable, easily-de¬ 
fined spleens of chronic malaria and may 
become an enthusiastic advocate of the 
method. Perhaps the most serious impedi¬ 
ment to its use is that even after consider¬ 
able experience with spleen palpation, dif¬ 
ferent examiners may express diverse opin¬ 
ions about the presence and extent of small 
degrees of splenic enlargement. As these 
constitute the major portion of the en¬ 
larged spleens encountered in this country, 
the main difficulty in depending upon sple¬ 
nometry in malaria reconnaissance is on 
obtaining reliable and comparable mea¬ 
surements on a large scale. 
A further consideration is the fact that 
the spleens of white children are more re¬ 
sponsive to malaria infection than are those 
of negroes. This is particularly true of 
tertian malaria which, in the negro, is com¬ 
paratively rare and almost always asymp¬ 
tomatic. Thus it is common experience to 
find more enlarged spleens than positive 
bloods among white children, while the re¬ 
verse is true among negro youngsters. It 
follows that geographic distributions of 
malariousness based on spleen size alone 
may be misleading in areas where the racial 
composition is highly variable. 
Blood-smear reconnaissance technique 
likewise has its pros and cons. The advan¬ 
tages are: (1) that smears can be collected 
by nurses, engineers, or other non-medical 
personnel, (2) that positive findings are 
objective and can be preserved for future 
verification, and (3) that species and game- 
tocyte determinations can be made. Their 
great disadvantages are: (1) the time and 
expense of processing and examination, 
and (2) their easy deviation by antima- 
larials which gives spuriously low infection 
rates. 
In the author’s opinion, the most pro¬ 
ductive and economical reconnaissance 
practice in this country would be to have 
the spleens of white children palpated by 
physicians and to have non-medical assis¬ 
tants make blood smears from negroes. 
These examinations may be restricted to 
rural populations, as little, if anything, is 
gained by including children living under 
strictly urban conditions. 
Second Consideration: Selection of 
Malaria-Control Areas 
Having developed the general picture of 
malaria intensity-distribution on a region¬ 
wide basis, the next step in planning ma¬ 
laria control is to decide just where it shall 
be done. Theoretically, this should be in 
the areas where it has been shown that the 
hazard is greatest or affects most people. 
Wherever possible, this public health prin¬ 
ciple should be allowed to dominate all 
others. Actually, malaria-control opera¬ 
tions cannot be carried out without cash or 
labor; therefore, except in situations where 
support is not locally derived, selection will 
probably be conditioned as much by con- 
