384 DISEASES OF UNCERTAIN ETIOLOGY 



blackwater patients showed one or more previous attacks of malaria. 

 In 230 cases subtertian parasites were found in 76'4 per cent, of cases^ 

 and benign tertian in 23*6 per cent, of cases. 



Most of the cases develop after twelve months' residence in the 

 tropics. After three to four years' residence in an endemic region the 

 ha^moglobinuric rate diminishes, hence length of residence appears to 

 be a factor. Decks and James sum up their investigations thus : — 



(i) Hiemoglobinuric fever is a manifestation of malarial toxicity, 

 for the most part brought about by repeated attacks of malaria. 



(2) It mav appear coincidentally with an acute malarial paroxysm. 



(3) It mav be determined by any depressing influence. 



(4) It mav be induced by the administrations of quinine. 



(5) Neither quinine alone, nor malarial infection alone, causes 

 hccmoglobinuria, but one or both of these, plus the toxin 

 eventuated during the course of one or more malarial attacks. 



(6) Syphilis is a predisposing factor, because of its influence in the 

 production of malarial recrudescences. 



(7) The treatment varies with the condition present. 



(8) To ensure against the recurrent attacks of malaria, with the 

 subsequent production of hasmoglobinuric fever, it is necessary 

 to raise the patient's resistance to a maximum, and to eradicate 

 the malaria by a thorough course of treatment with quinine. 



There is no proof that it has spread from one country to another ; on 

 the contrary, the disease manifests itself when certain conditions 

 relative to the epidemiology of malaria and to that of no other disease 

 are present. 



The conditions are : — 



(i) The presence of a population non-immune against malaria. 



(2) The prevalence of malaria in such quantity as to produce an 

 almost continuous infection in this population. 



(3) A large proportion of subtertian malaria, because the amount of 

 blackwater fever is in direct proportion to the intensity of this 

 variety. 



(4) The neglect of prompt and continued administration of quinine, 

 especially in primary attacks, to persons non-immune against 

 malaria. 



In every locality, without exception, where these conditions obtain, 

 hcemoglobinuric fever is found (Deeks and James). 



PATHOLOGY. 



Christophers and Bentley, working on the malarial theory, put 

 forward the following views : — 



(i) Laverania malari^e, the subtertian parasite, acts upon the endo- 



