Liver Involvement in Acute Mammalian Malaria with Special Reference to Plasmodium knowlesi Malaria

Abstract

This chapter concerns mainly with pathogenesis reactions in simian and to some extent in human and rodent malarias. The pathological and physiological disturbances in malaria vary considerably in severity and duration according to the infecting Plasmodium and the host. The processes involved have so far been most carefully studied in P . knowlesi infections in rhesus monkeys (Macaca mulatta). Discussion of the pathogenesis of the liver lesions in malaria must take into account all mechanisms that are responsible for functional and structural disturbances in the organ arising from non-specific reactions, and those that can be attributable more directly to the infection itself. The effects of the latter are frequently also non-specific because a given tissue can react in only a limited number of ways. An example of the first type of reaction in the liver in malaria is the response to the hyperactivity of the sympathetic nervous system initiated by the infection The second type of reaction is exemplified by the histotoxic activity of certain factors, to be discussed later, circulating in the blood of the infected host which cause fatty degeneration of parenchymal cells and inhibit mitochondria1 oxidative phosphorylation.