SUBTERTIAN FEVERS 



system of the body. It is in this way that the subtertian fevers can 

 produce signs and symptoms which medical practitioners are more 

 accustomed to associate with some other disease, and this explains 

 the curious phenomenon of malarial mimicry. As the parasite 

 Laverania malaricB can live in any organ, it can therefore produce the 

 signs and symptoms of any disease, and we know practically of no 

 clinical picture which it is impossible for this parasite to reproduce, 

 be it an acute illness or a chronic ailment, be it associated with 

 febrile symptoms or free from fever. Hence the great necessity for 

 the practitioner to be careful as to the diagnosis of malaria, and to 

 remember that in atypical cases which are of frequent occurrence 

 it is most difficult, and that the microscope is not infallible in its 

 aid, as negative microscopical findings do not exclude a diagnosis of 

 malaria, as will be emphasized in the section on diagnosis. 



The subtertian fevers are therefore capable of division from a 

 practical point of view into two great groups: — 



A. Typical Subtertian Fevers. 



B. Atypical Subtertian Fevers. 



In the first group comes simple subtertian fever, which shows an 

 intermittency of the symptoms, which is due to the fact that the 

 time required by a merozoite of Laverania malarice to attain to the 

 stage of a schizont is thirty-six to forty-eight hours, while a double 

 infection produces a quotidian fever, and more severe infections, 

 irregular, remittent, and bilious types of fever. Mixed and chronic 

 infections may also ensue as in the other types. 



The fevers of the second group may be subdivided according to 

 the syndrome which is produced, and which depends upon the organ 

 ' or system of the body which is attacked. 



We will now consider these various clinical conditions. 



A. TYPICAL SUBTERTIAN FEVERS. 

 The typical subtertian fevers may be divided into : — 



1. Simple subtertian fever. 



2. Double subtertian fever. 



3. Irregular subtertian fever. 



4. Remittent subtertian fever. 



5. Bilious subtertian fever. 



6. Mixed infections. 



I. Simple Subtertian Fever. 

 Definition. — This form of subtertian fever usually shows inter- 

 missions based upon a tertian type. 



Incubation. — The incubation period has been studied by Marchia- 

 fava and Bignami, who considered it to be of nine to ten days' 

 duration when acquired by natural mosquito infection, and to vary 

 from nine to nineteen days when acquired by experimental mosquito 



