The opening of I. MALARIA
DEFINITION AND SYNONYMS
=Definition.=—Malaria is a protozoal disease caused by three species of Plasmodium. In the clinically benign types of malaria we have that of benign tertian, due to P. vivax, with a tertian periodicity and that of quartan, due to P. malariae and showing a quartan or seventy-two hour periodicity. The clinically malignant type of malaria is due to P. falciparum, the parasite of malignant tertian or aestivo-autumnal malaria.
The benign malarial fevers are characterized by a frank chill and well marked distinctions of cold, hot and sweating stages. In malignant tertian there is an indefinite or dumb chill with prolonged hot stage. Diagnostic of malaria are periodicity, parasites and splenic enlargement. The malignant tertian parasite is the one responsible for the so-called cerebral and algid manifestations of perniciousness. Man is the intermediate host of the parasite while the sexual cycle or sporogony goes on in some species of mosquito of the anopheline subfamily, the definitive host.