Malaria is the predisposing cause and the exciting cause may be any of a number of different factors capable of lowering body resistance such as the occurrence of another malarial attack, the administration of quinine, particularly of the acid salts of quinine in rather large doses, refrigeration, as brought about by one’s clothes becoming wet and then later subjected to the chilling influence of a sea breeze, to excessive fatigue or dietetic or alcoholic excesses.
Quinine administration, particularly if associated with refrigeration, is the most common exciting factor.
As regards the association of malaria and blackwater fever Stephens, in a study of 390 cases of blackwater, found that 73% of the cases showed malarial parasites on the day preceding the haemoglobinuria, 47.5% on the day of the attack and 23% on the day following the appearance of the dark urine. Other workers give higher figures as 95, 70 and 20%.
Where one utilizes the methods of examining for increased percentage of large mononuclears or for melaniferous leucocytes, in those cases not showing malarial parasites, the percentage of evidence of malaria is greatly increased. It is necessary to understand that a small percentage of cases diagnosed as blackwater fever do not show evidences of malaria at autopsy and cases are recorded where blackwater has attacked persons who had never had malarial fever, such instances, however being exceptional.
The Quinine Theory.—This idea as to the causation of blackwater fever first originated with Veretas, in Greece, in 1858. Later Tomaselli supported this view in Italy and more recently it was advocated by Koch. Just as in connection with the influence of Koch’s great prestige much harm was done in prophylaxis against bovine tuberculosis so in this matter of quinine in the causing of blackwater the influence was unfortunate because many persons with severe malaria now refuse to take the specific quinine for fear of bringing on haemoglobinuria.
It may be stated that quinine alone, even in doses which are capable of producing profound toxic effects such as disturbances of sight and hearing, weak heart and collapse does not, other than exceptionally, cause haemoglobinuria. It has even been stated that quinine base and quinine tannate tend to prevent haemolysis, haemoglobinaemia and haemoglobinuria. Blackwater fever may develop without the previous administration of quinine.
Theory as to Acidosis with a Damaged Liver Plus Malaria and Acid Salts of Quinine.
MacGilchrist has recently advanced the idea that blackwater fever is brought about by an acidosis in one with a damaged liver plus malaria and the administration of acid salts of quinine. He thinks that one can safely give the quinine when alkalis are being given and that quinine base is protective against haemolysis.
Theory as to Its being Caused by a Piroplasm.