QUARTAN FEVERS 



1157 



II. THE QUARTAN FEVERS. 



Quartan malarial fever depends for its symptoms and course 

 upon the life-history oi Plasmodhtm malaricB, introduced into the 

 blood of man by an anopheline mosquito. Its clinical course will 

 depend entirely upon whether the parasites are of approximately 

 the same age, or whether they have been introduced into the body 

 on different days. 



If only parasites of approximately one age exist in the blood, a 

 typical quartan malarial fever ensues, with an interval of seventy- 

 two hours (the length of time which a merozoite takes to become 

 the fully developed schizont). vSuch a fever is called ' q.uartana 

 simplex,' or simpile quartan fever. 



If the parasites have been introduced on two different days, and 

 are therefore of different ages, the patient will develop fever on two 

 successive days, and be free from it on the third day; such a fever 

 would be called * quartana duplex,' or double quartan fever. 



If, however, the parasites were introduced on three successive 

 days, the fever may be daily — that is to say, may be a quotidian 

 fever — and this could only be recognized as belonging to the quartan 

 fevers by its parasite being discovered microscopically; such a 

 fever would be called a ' quartana triplex,' or triple quartan fever. 



If the parasites exist in greater numbers and groups than usual, 

 the fever may be irregular and sabcontinuous. 



There are, therefore, several types of quartan fevers — viz. : — 



A. Acute quartan malaria : — 



1. Simple quartan fever. 



2. Double quartan fever. 



3. Triple or quotidian quartan fever. 



4. Irregular subcontinuous quartan fevers. 



5. Mixed infections. 



B. Chronic quartan malaria. 



Simple Quartan Fever. 



Definition. — Simple quartan malaria is characterized by attacks 

 of fever recurring every seventy-two hours and separated by 

 apyrexial intervals which occupy the time required hy Plasmodium 

 malaricB to pass from the merozoite to the fully developed schizont. 



Incubation. — This has not been determined with any degree of 

 certainty. It is without doubt longer than either tertian or sub- 

 tertian. Celli, by experiment, came to the conclusion that it might 

 be very long — two months or more. 



By the experimental inoculation of blood, Marchiafava and 

 Bignami calculated the maximum incubation at 18 days, the mini- 

 mum at II days, and the mean at 143 days. We are not aware of 

 any accurate experiment to determine the incubation period after 

 the bite of infected mosquitoes. The only observation which we 

 know is the very doubtful one recorded by Buchanan in 1901, 



