214 REPORT OF THE HARVARD AFRICAN EXPEDITION 
While there has been considerable difference of opinion expressed from time 
to time about the value of the splenic index in the diagnosis of malaria, tempera- 
ture curves, cyclic manifestations and palpability of the spleen are not generally 
considered reliable for diagnosis, without microscopical investigation. From 
Clark’s ' recent and extensive study with West Indian negroes upon the value of 
palpation of the spleen and examination of thick blood films, he found in the 
examination of 11,000 adults a parasite rate of 23.5 per cent and a spleen rate 
in the same persons of only 3.5 per cent. In other words, only 110 of the 2,585 
adults whose blood films were positive for malarial parasites had also palpable 
spleens. If palpation alone had been relied on in this survey, the diagnosis 
would have been missed in 2,475 of 2,585 positive cases. In children of whom 
1,102 were examined, the parasite rate was 41.9 per cent and the spleen rate was 
only 22.78 per cent; that is, only 175 of the children whose blood films were 
positive for malaria had palpable spleens. If palpation alone had been em- 
ployed, the diagnosis would have been missed in 287 of 462 positive cases. 
Clark’s careful investigations demonstrate that as a quantitative method for 
selecting adult males in need of treatment for malaria, palpation of the spleen 
is unreliable and that its success is limited even when applied to children. 
Observations of this nature and other similar ones referred to would seem 
conclusively to demonstrate the fallacy of spleen palpation alone in the diagno- 
sis of malaria. 
SPLENOMEGALY 
One also notes a very great difference in the prevalence of marked spleno- 
megaly on the West Coast of Africa as compared with that which exists in parts 
of the Amazon basin in Brazil.?, Malaria widely prevails in both regions, but 
on the West Coast of Africa advanced splenomegaly is not a striking feature, 
whereas in the Rio Branco regions it is, and large spleens, to or below the level 
of the umbilicus, are common. 
In connection with this subject it is of interest to note the recent studies of 
Lambert and Olivera * who in seven cases of lethal malaria found only one spleen 
weighing as much as 820 grams. In three of the cases the spleen weighed only 
250 grams or less, while in a number of other cases of subsidiary malaria where 
death occurred from other causes, the spleen was either not distinctly overweight 
or was even somewhat less than the normal weight of 150 to 170 grams. 
Ziemann,’ who had a wide experience with malaria on the West Coast of 
Africa, tends to emphasize the fact that marked splenomegaly is comparatively 
rare in association with malaria throughout the Cameroons. 
Clark ° found in Central America (the Caribbean area), that while extreme 
cases of splenic enlargement, 1000 grams or more in weight, were not infrequent 
in the Latin-American labor class, that they were very rarely encountered in the 
1 Clark, H. C: Amer. Jour. Trop. Med. (1928), VIII, 423. 
2 Strong and Shattuck: Medical Report of Hamilton Rice 7th Exped. to the Amazon (1926), p. 74. 
8 Lambert and Olivera: Porto Rico Review of Public Health and Trop. Med. (1929), IV, 299, 
4 Ziemann: Malaria und Schwarzwasserfieber, Mense’s Handbuch der Tropenkrankheiten, Bd. IIT 
(1924), pp. 211, 218-287. 
5 Clark: United Fruit Co. Meaical Dept. 16th Annual Report (1927), p. 99. 
