70 DISEASES DUE TO PROTOZOA 



1640 was the first advance in our knowledge of them, when the 

 introduction of cinchona enabled a differentiation of malarial from 

 other febrile diseases. This drug was probably first used by the 

 Indians of Peru, and later rediscovered by R.C. priests. The 

 Countess d'El Cinchon, the wife of the viceroy of Peru, sent some of 

 it to Europe, hence its name. 



1 71 7. The Italians used drainage as a protective measure. 



1847. Meckel described the peculiar pigmentation found post 

 mortem in the spleen and blood of one who had died from malaria. 



1854. Planer demonstrated the pigment in living finger blood 

 from a malarial patient. It was not then known that these pigments 

 were the parasites. 



1880. Laveran established definitely the parasitic nature of the 

 infection. Golgi demonstrated the definite correlation between the 

 development of the parasite and the periodicity of the fever paroxysms. 



1881. Mosquito nets were first used in India. 



1885. Golgi and others distinguished and differentiated species of 

 parasites and an asexual life-cycle. 



1894. Sir Patrick Manson suggested that the malarial parasite 

 must have an extra-corporeal life and probably in a blood-sucking 

 insect, e.g., the mosquito. 



1897. McAllum saw the conjugation of living sexual forms. 



Ross demonstrated malarial parasites in the stomach wall of the 

 mosquito. 



1900. The microscope was not much used in the tropics prior to 

 this date. 



It is interesting to note that in 1763, 12,000 Frenchmen disembarked 

 at Kourou, French Guinea. They lost 10,000 of their number by death 

 from disease, chiefly malaria, within twelve months. 



AETIOLOGY. 



This will be dealt with under the heads of Predisposing and 

 Exciting causes. 



Predisposing causes. 



(i) Residence in an area infected with malarial carriers (humans 

 with gametocytes) and mosquitoes capable of transmitting 

 the disease. 



(2) Residence in an infected area Avitli meteorological conditions 

 of air, moisture and temperature particularly suitable for 

 the development of the parasite, their carriers and larvcTS. 

 Warm, marshy places in the wet seasons are ideal. There 

 must be an average temperature of 60° F. at least. 



