310 



PARASITIC PROTOZOA IN RELATION TO THE WAR. 



for the cerebral forms of malaria, which may have serious or 

 fatal consequences. 



It is well known that malaria was usually considered to be 

 amenable to treatment with quinine. This dru.s^ is capable of 

 destroyin<T the asexual generations or merozoites in the blood, but 

 the crescentic sexual forms of the malignant tertian parasites are 

 often resistant to quinine. Recently it has been found that intra- 

 venous injections of tartar emetic were effective in destroying 

 crescentic gametocytes in man. I'he treatment has been tried on 

 a few cases in various places, and has recently been practised in 

 Johannesburg at the Wanderers' Hospital by Orenstein and 

 Watkins-Pitchford with excellent results. In the Balkan war 

 zone there was much malaria in certain valleys and low-lying 

 ground, and quinine-resistant strains of parasites occurred. Cere- 

 bral malaria also was relatively common. Anopheline mosquitoes 

 occurred in the neighbourhoods, and there is little doubt that 

 some of the native population served as reservoirs of the para- 

 sites. 



Were there no Anophelines (which mosquitos are character- 

 ized by having spotted wings) there would be no malaria, since 

 the sexual cycle of the parasites is only completed in the body of 

 the female insect. The vniion of the malarial gametes (male 

 and female parasites) in the lumen of the mosquito's stomach, 

 with the production of a motile zygote or ookinete, is followed 

 by the passage of the latter through the wall of the insect's 

 stomach and encystment on the outside thereof. Enormous 

 multiplicative activity takes place within the oocyst, and results 

 in the formation of many sporozoites, which ultimately find their 



Fig. 22. 



way to the salivary glands of the insect, whence they are inocu- 

 lated into man with the saliva when the insect next feeds. 



Anti-malarial campaigns take two forms: one against mos- 

 quitos, the other against the parasite in r-ic human host. Quinine 

 and organic salts of arsenic or antimony attack most of the forms 

 of the parasite in man. The main anti-mosquito measures in- 

 clude drainage of swamps and unnecessarv pools, removal of all 

 useless receptacles capable of containing water in which mos- 

 quitos may 'breed, the screening of all household receptacles, 

 and periodic oiling of water surfaces that cannot be screened. 

 The use of a mosquito net of fine mesh when sleeping is essen- 



