Chapter 14 - Malaria

Abstract

This chapter provides an analysis of the disease malaria and discusses the dearth of progress in the global management of this disease. Malaria is transmitted by an insect vector—in the case of humans, the Anophelesmosquito. The parasite uses host saccharides in both the insect vector and humans for recognition/binding events. Experimental results show that these host saccharides are usually anionic in nature and involve heparan sulfate, chondroitin sulfate, and sialyl residues. Specific domains on parasite surface proteins are identified that are involved in these phenomena and confirm the charge-based nature of the primary interactions. Direct glycosylation of parasite proteins is primarily through the attachment of glycosylphosphatidylinositol anchors, a predominant mechanism for surface immobilization of parasite proteins. The anchors have a Man4 structure and are immunogenic in humans. Explicit identification of any protein of the parasite that contains N- or O-linked saccharides has not been accomplished although a small amount of high mannose structures are present. The lack of a convenient animal model and the difficulty in growing the parasite in vitro are contributing factors. Disease control that targets the vector (insecticide, bed nets) has had some limited success but is not a long-term solution. The magnitude of the problem is underscored by the reintroduction of DDT in several areas of sub-Saharan Africa.