The Haemosporidia, which comprise the malaria parasites, have probably evolved from Coccidia of the intestinal epithelium of the vertebrate host by adaptation first to some tissues of the internal organs and then to life in the circulating cells of the blood.The present opinion is that, among the malaria parasites of primates, the genus Hepatocystis and the "quartan group" of plasmodia are the most ancestral, followed by the "tertian group"; from the evolutionary viewpoint the subgenus Laverania is probably the most recent.Studies recently completed and research in hand on malaria parasites of apes and monkeys, combined with the possibility of assessing the infectivity of new simian parasites to Anopheles and to man, will be of great importance for a better understanding of the probable evolution of primate malarias. The fact that several genera of the Anthropoidea evolved in an ecological area where the association with the existing insect vectors of various plasmodia was close is suggestive of Africa as the original home of primate malaria. It is probable that the disease spread up the Nile valley to the Mediterranean shores and Mesopotamia, to the Indian peninsula and to China. From these main centres malaria invaded a large part of the globe.It is also probable (though not proved) that malaria existed in the Americas before the Spanish conquest, and there is some likelihood that sea-going peoples brought it to the New World long before Columbus's voyages. Modern immunological methods applied to the study of the mummified remains of ancient inhabitants of America may help to solve this question.

Africa↗

PubMed1964

CHANGING TIDES OF CHEMOTHERAPY OF MALARIA.

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Antimalarials↗

PubMed1964

A SIMPLE DEVICE FOR ANAESTHETIZING MOSQUITOS WITH CARBON DIOXIDE.

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Anesthesia↗

PubMed1964

SELECTION OF A STRAIN OF ALBINO MICE REFRACTORY TO PLASMODIUM BERGHEI INFECTION.

Some features of the natural history of malaria in holoendemic areas can be explained by the presence of acquired immunity. There is also evidence that transmission of humoral antibodies in utero from the immune mother plays some part in the transient protection of the offspring. Little is known about the importance of a genetic factor.The possibility of inheritance of immunity to malaria was investigated on six generations of a strain of white mice originating from 50 parents fully susceptible to infection with Plasmodium berghei. These mice were interbred in such a way that each generation was exposed to an infection attenuated by chloroquine. The survivors were mated with a view to selecting a strain with a decreased susceptibility to infection. Some 16% of mice in the sixth generation and one animal out of four in the seventh were able to resist the initial inoculation with 0.1 million parasites. By the sixth generation, there was evidence of reduction of the period of primary parasitaemia and lengthening of the prepatent period, suggesting that some selection of animals with greater tolerance had occurred. A decrease of fertility, particularly obvious in the seventh generation, limited the number of surviving animals and the experiment had to be discontinued.

Animals↗

PubMed1963