200 
MALARIA 
peripheral circulation three days prior to 
the onset of paroxysms. It has been very 
rare in our experience to observe a febrile 
reaction prior to the first appearance of 
parasites in colored patients. In white per¬ 
sons the attainment of high densities by the 
parasites before the onset of fever is, on the 
other hand, uncommon, and frequently the 
initial fever precedes the first detected 
parasites by one or more days. 
It is noteworthy that the parasite density 
at the onset of fever is usually touch lower 
Fig. 6. No. B-999 (P. falciparum ): Shows the 
association of high parasite density and normal 
• temperature on alternate days, and of low parasite 
density and elevated temperature on the interven¬ 
ing days. 
than that which obtains subsequently at 
the onset of recurrences. In other words, 
some tolerance for the parasite has devel¬ 
oped and a greater number of them is neces¬ 
sary to provoke a febrile response. As a 
corollary, one usually observes that the 
parasite count is greater at the termination 
of the primary attack than it was at the 
onset. 
In the case of infections with paroxysms 
occurring at tertian intervals an interesting 
phenomenon may be present (Fig. 6). 
When one examines smears made at inter¬ 
vals of 24 hours and enumerates the para¬ 
sites per cmm it may sometimes be noted 
that the parasite density shows a daily alter¬ 
nation between low and high levels and that 
there is an inverse relationship between the 
level of the parasite density and the inci¬ 
dence of paroxysms; the latter occur on the 
day of the lower parasite count and are 
absent on the following day when the para¬ 
site density is greater. Such alternation 
may be present over a period of several 
days. 
Clinical types of falciparum malaria. 
The clinical classification of P. falciparum 
infections has been made very cumbersome. 
Systems of classification based on the febrile 
reaction alone are not satisfactory chiefly 
because the degree or type of fever is not 
consistent. Elaborate divisions and subdi¬ 
visions on the basis of clinical types and 
syndromes serve only to indicate that this 
disease is very protean in its manifestations 
and therefore must be considered in making 
a diagnosis of an illness in any person who 
has been in a position to contract it. 
It is convenient to consider, in the first 
place, that P. falciparum malaria may (a) 
be of a simple type, involving the body as 
a whole but attacking no system of organs 
in particular, or (b) show localizing symp¬ 
toms denoting involvement of one or more 
organs predominantly; these infections 
usually arise from those of the first group. 
The former group, though they also occur 
in tropical areas, comprise the majority of 
estivo-autumnal attacks that occur in sub¬ 
tropical zones. Although many of them are 
relatively benign in character, it is wise to 
consider that all P. falciparum infections 
are endowed with fatal potentialities (the 
type of illness which follows inoculation is 
dependent upon individual factors and the 
administration of specific medication). The 
parasites, though giving no signs of localiza¬ 
tion, may show an extreme degree of inva¬ 
siveness and if unchecked, multiply rapidly 
until the patient is overwhelmed and death 
ensues. Of course in many such instances 
intercurrent disease, poor physical condi¬ 
tion or lack of resistance for other reasons 
