Malaria

Abstract

Malaria is a disease of the blood resulting from infection by protozoan parasites of the genus Plasmodium , transmitted by female Anopheline mosquitoes. Five species of Plasmodium infect humans, Plasmodium falciparum , Plasmodium vivax , Plasmodium ovale , Plasmodium malariae and Plasmodium knowlesi . The parasite life cycle includes stages in the mosquito and in human liver cells and red blood cells, which they penetrate and feed on. Plasmodium falciparum is the main cause of malaria deaths, especially of young African children. Cerebral malaria, renal and pulmonary failure are major pathologies. Frequent infections gradually confer immunity over several years, but this is rarely complete. Many antimalarial drugs are available for prophylaxis and treatment, but emerging parasite resistance limits their use. Several vaccines are being tested, with some moderate success. Efforts to control malaria include breeding grounds drainage, insecticide sprays and use of insecticide‐impregnated bednets. With the help of several major global initiatives, there are reports of significant reductions of malaria cases. Key Concepts: Malaria is a disease caused by infection of red blood cells (erythrocytes) by protozoan parasites of the genus Plasmodium. Malaria is a major global disease affecting many millions worldwide and causing up to a million or more deaths a year, mostly children under 5 years in sub‐Saharan Africa. Malaria is caused by five species of Plasmodium , the most lethal being Plasmodium falciparum . Malaria parasites are transmitted to humans by the bite of infected female mosquitoes, and then the parasite multiplies first in the liver and later in the bloodstream before passing back to the mosquito as it feeds. Malaria has many symptoms, which include cyclic episodes of fever, the frequency depending on malaria parasite species. Severe malaria is frequently fatal if not treated rapidly. The pathology of malaria is related to blood infections, either by destroying erythrocytes or by blocking small blood vessels (sequestration) as occurs in cerebral malaria. Acquired immunity builds up gradually and its maintenance depends on repeated infections; innate immunity is often associated with genetic diseases of the blood. Numerous antimalarial drugs have been developed including those related to quinine and more recently artmesinin, but parasites have developed resistance to most of these in some parts of the world; several vaccines are now under trial. Other efforts to control malaria include elimination of mosquitoes and draining their breeding grounds plus the use of insecticide‐impregnated bednets to minimise transmission.

MRE11 is crucial for malaria transmission and its absence affects expression of interconnected networks of key genes essential for life

“…Caused by infection with the apicomplexan parasite Plasmodium spp., malaria is transmitted by the Anopheles mosquito. The parasite lifecycle has several morphologically distinct developmental stages in the mammalian host and mosquito vector (2). The host is infected by sporozoites, which migrate in the blood to the liver, where the parasite replicates asexually multiple times in a hepatocyte to produce merozoites.…”

MRE11 Is Crucial for Malaria Parasite Transmission and Its Absence Affects Expression of Interconnected Networks of Key Genes Essential for Life

“…Caused by infection with the apicomplexan parasite Plasmodium spp., malaria is transmitted by the Anopheles mosquito. The parasite life cycle has several morphologically distinct developmental stages in the mammalian host and mosquito vector [2]. The host is infected by sporozoites, which migrate in the blood to the liver, where the parasite replicates asexually multiple times in a hepatocyte to produce merozoites.…”