INFECTION IN INTERMEDIATE HOST: FALCIPARUM 
205 
areas who are repeatedly infected and who 
receive little or no treatment between at¬ 
tacks says “the result is that they pass 
into a condition which is correctly named 
‘ chronic malaria. ’ ’ ’ Marehiafava and Big- 
nami, on the other hand, believe that dis¬ 
tinction should be made between chronicity 
following a first attack and that resulting 
from a succession of infections. In a re¬ 
cent paper on chronic malaria, Fonde and 
Fonde (1939) expressed the opinion that 
statistics regarding the incidence of ma¬ 
laria, based on the demonstration of para¬ 
sites rather than on clinical evidence, are 
not a true indication of the extent of ma¬ 
laria. We deplore the promulgation of this 
doctrine and feel that there is already far 
too great a tendency to blame malaria for 
many diverse debilitating conditions and 
elevations of temperature in the absence of 
demonstrable parasites, and chiefly because 
a diagnosis of malaria, rightly or wrongly, 
had once been made. Mannaberg defined 
chronic malarial infection as one continu¬ 
ing for months and specified that the con¬ 
tinuance was not dependent on reinfection 
“but on obstinate persistence of the virus.” 
It is perhaps timely to express the opinion 
that P. falciparum malaria is an infec¬ 
tion which is not as prone to chronicity as 
is generally thought. Our own experience 
leads us to believe that it is less given to 
chronicity than is the disease induced by 
P. vivax. Manson-Bahr (1931) commented 
on the greater persistence of benign tertian 
infections. 
The tendency to a few relapses is a recog¬ 
nised characteristic of P. falciparum ma¬ 
laria and we have noted as many as four 
or more of these before immunity has de¬ 
veloped to a point where they cease. In 
our own experience renewal of clinical ac¬ 
tivity beyond an eight-week period from 
the cessation of the primary attack has been 
rare and no recurrence has been noted after 
a six-month period. In a previously men¬ 
tioned paper by Boyd and Kitchen (1937a) 
it was observed that patients inoculated in 
the last quarter of the year have shorter 
incubation periods, longer attacks and 
fewer instances of renewed activity after 
cessation of the primary attack, whereas 
infections induced during the winter tend 
to have longer incubation periods, shorter 
attacks, and a greater tendency toward re¬ 
newal of clinical activity. The incidence 
of relapses and recurrences may thus be 
taken as an indication of the effectiveness of 
the immunity built up during the primary 
attack. Both chronic malaria and malarial 
cachexia are stated to be the result of un¬ 
treated or inadequately treated attacks of 
malaria. In our experience, lack of treat¬ 
ment during the primary attack in a person 
in good physical condition is conducive to 
more rapid development of specific im¬ 
munity, and interference with the primary 
attack will directly influence the relapse 
rate. Thus two-thirds of our patients 
(Boyd and Kitchen 1937a) receiving small 
doses of quinine during the primary attack 
(to control the therapeutic infections) ex¬ 
hibited relapses, whereas slightly more than 
a quarter of those receiving no quinine did 
likewise. Over 90 per cent of our patients 
who received a week’s course of quinine 
(after the method of Sinton 1930) subse¬ 
quent to the primary attack experienced 
no relapses. It is recognized that the de¬ 
velopment and maintenance of immunity 
in malaria are adversely affected by poor 
hygienic conditions and concurrent or in- 
tereurrent infections, and it seems likely 
that these factors have been responsible for 
much of the chronicity for which P. falci¬ 
parum has been primarily blamed. Inade¬ 
quate, irregular, “hit or miss” treatment 
may lead to chronicity by reason of delay¬ 
ing or interfering with the immunogenic 
process. We believe, however, that much 
of the so-called chronicity and cachexia in 
P. falciparum malaria is due to causes other 
than lack of or inadequate treatment. 
There undoubtedly exist in endemic areas 
several immunologically distinct strains of 
P. falciparum and it would seem to be 
rather difficult to differentiate between re¬ 
lapses and reinfections in all instances dur¬ 
ing the season of transmission, although it 
is likely that a reinfection would involve 
a greater parasite density and a more severe 
clinical reaction. Milder superinfections 
