Transmission Blocking Strategy for Malaria Eradication: The Role of Antimalarial Agents

Abstract

Elimination and Eradication is an important component of the Global Strategy for combating malaria and one of the ways of achieving this purpose is blocking transmission of malaria parasites from humans to mosquito vectors. The ability of plasmodium to cease asexual replication in the erythrocytes of the human host and commit to formation of gametes necessary for sexual replication in the gut of the mosquito vector is essential for efficient transmission of malaria. Although a conserved member of the Apicomplexan AP2 family of transcriptional factors acts as the master switch in triggering the transcriptional cascade that initiates gametocytogenesis, some environmental factors including some antimalarial drug treatments, are believed to switch on the gene(s) that determine the commitment to the sexual phase. Antimalarial agents have different effects on gametocyte carriage depending on their mechanisms of action. This review enumerates the role of various classes of antimalarial agents in either promoting or preventing plasmodium gametocytogenesis and points out the need to, in addition to exiting gametocytocides, design new drugs that are capable of preventing gametocytogenesis and/or killing mature gametocytes in humans; or preventing gametogenesis and fertilization in the mosquito.