I202 



THE MALARIAL FEVERS 



it reduces their numbers to less than one per cubic millimetre of blood if given 

 daily in doses of 20 to 30 grains for three weeks; this action is believed to be 

 due to cutting off the source of supply by killing the asexual forms. Methy- 

 lene blue in doses of 12 grains daily is said by Thomson to reduce the number 

 of crescents, probably by some direct destructive action. Quinine-resisting 

 forms of the parasite have often been reported from South America, and have 

 also been studied by Ross and Thomson, who have found a true parasitic 

 relapse during thorough quinine treatment. In these cases the quinine dosage 

 must be increased. We have administered 2 grammes by intramuscular 

 injection and i gramme by the mouth after a few hours as a single dose 

 in such a case with very beneficial results. 



Immunity of the Parasite. — ^The immunity of the malarial parasite 

 against quinine has as yet been but little studied, but this is a subject of the 

 greatest importance at the present time, when quinine prophylaxis is being 

 extensively employed. It has, however, been commonly noticed that the 

 doses of quinine have often to be increased in order to cure an attack of fever 

 in the individuals who have taken quinine more or less irregularly, and that 

 persons who have taken quinine regularly when in an endemic area may have 

 an attack of malarial fever after leaving this area and ceasing the drug. 



Prophylactic Use. — This will be discussed in the section on Prophylaxis. 



Other Drugs. — It is almost a work of supererogation to mention other 

 drugs in the treatment of malaria, such as cuprein, mercury, atoxyl, and 

 treatment by the serum of immune animals, and by violet light or in the dark. 

 Methylene blue, however, has been used by several authors in the dose of 

 2 grains every four hours. In our experience its ef&cacy cannot be compared 

 to that of quinine. 



Surveyor has recommended the administration of 2 grains of picric acid 

 twice or three times a day by the mouth as a method of destruction for the 

 crescents of L. malaricB. The drug can also be administered by injections of 

 sodium pi crate. Nicolle and Conseil and more recently Falconer, Anderson, 

 Micheli, Quarelli and others have tried salvarsan in malaria, with only 

 moderate results. If used, it must be combined with quinine. Neosalvarsan 

 has been found to be useless in subtertian fevers, but it and salvarsan may 

 act upon Plasmodium vivax intravenously or intramuscularly. For dosage 

 see p. 13 13. 



Tartar emetic has been used by Rogers, but the researches by Low and 

 others have shown that when administered alone it has no effect upon the 

 malaria parasites. Rontgen therapy is useless, though the spleen may get 

 smaller. 



PROPHYLAXIS. 



The very great success which has followed every serious attempt 

 at prophylaxis undertaken during the last few years has made it 

 the urgent duty of each community to scientifically apply a well 

 thought out scheme of a not too expensive nature to its district 

 with the view of reducing the malaria endemic therein. 



In order that a disease may be scientifically prevented, a thorough 

 knowledge of its aetiology must be acquired and disseminated not 

 merely among medical men, but also among the public. We know 

 that malaria depends upon — 



1. The presence of numerous human beings infected Vv^ith male 



and female gametocytes. 



2. The presence of numerous anophelines in which the 



gametocytes are capable of developing into sporozoites. 



3. Free access of these anophelines to the infected human 



beings. 



