Pak. i 
MEDICAL AND PATHOLOGICAL INVESTIGATIONS 
IN LIBERIA AND THE BELGIAN CONGO 
By RICHARD P. STRONG and GEORGE C. SHATTUCK 
XVI 
INFECTIOUS DISEASES 
MALARIA 
ATTENTION has been called to the high rate of infection with malarial para- 
sites that we found in Liberia among the Kru children on the coast. Of a 
group of thirty-six children, thirty-one, or eighty-six per cent, showed malarial 
parasites in the blood. The great majority of these children were up and about. 
Some no doubt at times had distinct malarial paroxysms with chills and fever, 
but the majority showed no other marked evidence of disease at the time they 
were examined except that in thirteen, or thirty-eight per cent, the spleen was 
palpable. However, no case of marked splenomegaly, with the lower border of 
the spleen reaching to the level of the umbilicus, for example, occurred among 
them. It is impossible to say what percentage of these children acquire a high 
active immunity against malaria in adult life and what percentage acquire only 
an increased tolerance to the toxin of the malarial parasite. 
In Roumania, Ciuea, Ballif and Viéru! have recently concluded as the result 
of 297 observations made during the therapeutic inoculation of persons suffering 
from diseases of the nervous system with blood containing malarial parasites, 
that immunity to malaria is not uncommon in that country, where the disease 
is prevalent and some 900,000 persons are infected. 
We of course saw cases of active malaria in adult Americo-Liberians, with 
chills and fever, whose long residence had not rendered them thoroughly im- 
mune or entirely insusceptible to the action of the malarial toxin. 
In the interior of Liberia, in people living between the St. John and the Duk- 
wia River, who were examined at random and who were not ill with fever, 
thirty-three per cent of the inhabitants were found to be infected with malarial 
parasites and sixteen per cent showed more or less enlargement of the spleen. 
Among these apparently moderately healthy people, no infections were encoun- 
tered where the number of malarial parasites found was large. From our investi- 
gations it seemed apparent that there is less malaria generally in the interior 
of Liberia than upon the coast. The amount of infection certainly varies in dif- 
ferent localities in the interior, but we found no fever-ridden settlements, and no 
‘ Ciuca, Ballif and Viéru: Arch. Roumaines Path. Expér. et Microbiol. (1928), I, 577. 
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