THE INFECTION IN THE INTERMEDIATE HOST: 
SYMPTOMATOLOGY, QUARTAN MALARIA 
By S. F. KITCHEN 
INTERNATIONAL HEALTH DIVISION, ROCKEFELLER FOUNDATION, TALLAHASSEE, FLA. 
Quartan malaria, least common of the 
malarias and uncommon in North America, 
shows a number of differences from falci¬ 
parum and vivax malaria in symptoma¬ 
tology. It is more like the latter, however, 
and in this connection, certain characteris¬ 
tics of P. malariae, the causative organ¬ 
ism, are of interest. 
Firstly, as in the case of P. vivax, spol¬ 
iation of the mature schizont occurs, at 
least in part, in the peripheral circulation 
and therefore there is present much less 
evidence of localized damage to the viscera, 
such as is frequently characteristic of fal¬ 
ciparum infections. Secondly, this parasite 
requires 24 hours longer than P. vivax and 
P. falciparum to complete the schizogonous 
cycle. Thus the evolution of the attack is 
slower, the density of parasites in the 
peripheral circulation rarely exceeds 20,000 
per cmm, and the marked invasiveness of P. 
falciparum is not, as a rule, evident. 
Thirdly, the schizogonous stages of the 
parasite are better synchronized than those 
of P. falciparum, resulting in great regu¬ 
larity of the individual paroxysms, such as 
is seen in vivax infections. Fourthly, in 
our experience P. malariae appears to be 
more toxic in relation to parasite densities 
attained than does either P. vivax or P. 
falciparum. 
In a recent article, Boyd (1940b) has re¬ 
viewed our experience (5 naturally and 
38 artificially induced infections) with 
quartan malaria and the data therein pre¬ 
sented have been drawn upon freely in the 
preparation of the following account. 
Prodromal period. In common with the 
other malarias, the quartan infection will 
usually, though not invariably, provoke 
prodromal symptoms not particularly dis¬ 
tinguishing in nature. In the case of 
quartan malaria, however, such prodromes 
will usually occur during a period when 
the parasites are demonstrable in the blood 
smears, inasmuch as the appearance of 
parasites in almost every instance precedes 
the clinical onset by at least a few days. 
The usual premonitory symptoms of lassi¬ 
tude, anorexia, possibly nausea, headache 
and vague general aching or chilly sensa¬ 
tions may be present for one or more days 
prior to the onset of paroxysms. 
Fever. From the clinical aspect, quartan 
malaria is usually classified according to 
the arrangement of the paroxysms. The 
fact that the life cycle of the schizont is 
about 72 hours in duration and that there 
may be 1, 2 or 3 cycles of parasites suffi¬ 
ciently active to produce fever provides 
3 possible classes. The infection may 
be (a) simple in type, exhibiting a par¬ 
oxysm at intervals of 72 hours; or (b) 
double quartan, in which case there is a 
paroxysm on two successive days followed 
by a day without fever, then 2 more suc¬ 
cessive paroxysms and an afebrile day and 
so forth; or (c) triple quartan, in which 
there occur daily paroxysms. 
The febrile reaction in these infections 
is usually one of regular periodicity from 
the start and the paroxysms as a rule are 
distinct, although one may occasionally ob¬ 
serve that two adjacent paroxysms are so 
close together that the first temperature 
curve has not quite returned to normal 
before the second rise commences (Fig. 1, 
No. B-2814). James (1910) considered the 
temperature curves of his quartan patients 
to be irregular although from the appear¬ 
ance of his charts it is assumed that he 
referred to the appearance and disappear¬ 
ance of cycles. There is rarely observed 
a preliminary exhibition of remittent fever 
such as one frequently sees at the onset 
in P. vivax malaria. The onset in quartan 
