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Cold Spring Harbor Perspectives in... Jan 2018In the mosquito-human life cycle, the six species of malaria parasites infecting humans (, , , , , and ) undergo 10 or more morphological states, replicate from single... (Review)
Review
In the mosquito-human life cycle, the six species of malaria parasites infecting humans (, , , , , and ) undergo 10 or more morphological states, replicate from single to 10,000+ cells, and vary in total population from one to many more than 10 organisms. In the human host, only a small number of these morphological stages lead to clinical disease and the vast majority of all malaria-infected patients in the world produce few (if any) symptoms in the human. Human clinical disease (e.g., fever, anemia, coma) is the result of the parasite preprogrammed biology in concert with the human pathophysiological response. Caveats and corollaries that add variation to this host-parasite interaction include parasite genetic diversity of key proteins, coinfections, comorbidities, delays in treatment, human polymorphisms, and environmental determinants.
Topics: Female; Humans; Malaria; Malaria, Cerebral; Placenta; Plasmodium; Pregnancy; Species Specificity; Virulence Factors
PubMed: 28533315
DOI: 10.1101/cshperspect.a025569 -
The American Journal of Tropical... Jul 2018Important strides have been made within the past decade toward malaria elimination in many regions, and with this progress, the feasibility of eradication is once again... (Review)
Review
Important strides have been made within the past decade toward malaria elimination in many regions, and with this progress, the feasibility of eradication is once again under discussion. If the ambitious goal of eradication is to be achieved by 2040, all species of infecting humans will need to be targeted with evidence-based and concerted interventions. In this perspective, the potential barriers to achieving global malaria elimination are discussed with respect to the related diversities in host, parasite, and vector populations. We argue that control strategies need to be reorientated from a sequential attack on each species, dominated by to one that targets all species in parallel. A set of research themes is proposed to mitigate the potential setbacks on the pathway to a malaria-free world.
Topics: Animals; Anopheles; Antimalarials; Chloroquine; Disease Eradication; Host-Parasite Interactions; Humans; Malaria; Malaria, Falciparum; Malaria, Vivax; Mosquito Vectors; Plasmodium falciparum; Plasmodium knowlesi; Plasmodium malariae; Plasmodium ovale; Plasmodium vivax; Primaquine
PubMed: 29761762
DOI: 10.4269/ajtmh.17-0869 -
Lancet (London, England) Sep 2013Malaria-eliminating countries achieved remarkable success in reducing their malaria burdens between 2000 and 2010. As a result, the epidemiology of malaria in these... (Review)
Review
Malaria-eliminating countries achieved remarkable success in reducing their malaria burdens between 2000 and 2010. As a result, the epidemiology of malaria in these settings has become more complex. Malaria is increasingly imported, caused by Plasmodium vivax in settings outside sub-Saharan Africa, and clustered in small geographical areas or clustered demographically into subpopulations, which are often predominantly adult men, with shared social, behavioural, and geographical risk characteristics. The shift in the populations most at risk of malaria raises important questions for malaria-eliminating countries, since traditional control interventions are likely to be less effective. Approaches to elimination need to be aligned with these changes through the development and adoption of novel strategies and methods. Knowledge of the changing epidemiological trends of malaria in the eliminating countries will ensure improved targeting of interventions to continue to shrink the malaria map.
Topics: Adolescent; Adult; Africa South of the Sahara; Aged; Civilization; Cluster Analysis; Cross-Sectional Studies; Developing Countries; Emigration and Immigration; Female; Humans; Malaria; Malaria, Falciparum; Malaria, Vivax; Male; Middle Aged; Occupational Diseases; Plasmodium malariae; Plasmodium ovale; Population Dynamics; Young Adult
PubMed: 23594387
DOI: 10.1016/S0140-6736(13)60310-4 -
Tropical Parasitology 2023Nonhuman primate (NHP) malaria poses a major threat to the malaria control programs. The last two decades have witnessed a paradigm shift in our understanding of the... (Review)
Review
Nonhuman primate (NHP) malaria poses a major threat to the malaria control programs. The last two decades have witnessed a paradigm shift in our understanding of the malaria caused by species other than the traditionally known human species - , , , and . The emergence of the malaria parasite of long-tailed macaque monkeys, , as the fifth malaria species of humans has made the scientific community consider the risk of other zoonotic malaria, such as , , , and others, to humans. The development of knowledge about as a pathogen which was earlier only known to experimentally cause malaria in humans and rarely cause natural infection, toward its acknowledgment as a significant cause of human malaria and a threat of malaria control programs has been made possible by the use of advanced molecular techniques such as polymerase chain reaction and gene sequencing. This review explores the various aspects of NHP malaria, and the association of various factors with their emergence and potential to cause human malaria which are important to understand to be able to control these emerging infections.
PubMed: 37860614
DOI: 10.4103/tp.tp_79_22 -
Microorganisms Jan 2022Cysteine proteases belonging to the falcipain (FP) family play a pivotal role in the biology of malaria parasites and have been extensively investigated as potential...
Cysteine proteases belonging to the falcipain (FP) family play a pivotal role in the biology of malaria parasites and have been extensively investigated as potential antimalarial drug targets. Three paralogous FP-family cysteine proteases of , termed malapains 2-4 (MP2-4), were identified in PlasmoDB. The three MPs share similar structural properties with the FP-2/FP-3 subfamily enzymes and exhibit a close phylogenetic lineage with vivapains (VXs) and knowpains (KPs), FP orthologues of and . Recombinant MP-2 and MP-4 were produced in a bacterial expression system, and their biochemical properties were characterized. Both recombinant MP-2 and MP-4 showed enzyme activity across a broad range of pH values with an optimum activity at pH 5.0 and relative stability at neutral pHs. Similar to the FP-2/FP-3 subfamily enzymes in other species, recombinant MP-2 and MP-4 effectively hydrolyzed hemoglobin at acidic pHs. They also degraded erythrocyte cytoskeletal proteins, such as spectrin and band 3, at a neutral pH. These results imply that MP-2 and MP-4 are redundant hemoglobinases of and may also participate in merozoite egression by degrading erythrocyte cytoskeletal proteins. However, compared with other FP-2/FP-3 enzymes, MP-2 showed a strong preference for arginine at the P2 position. Meanwhile, MP-4 showed a primary preference for leucine at the P2 position but a partial preference for phenylalanine. These different substrate preferences of MPs underscore careful consideration in the design of optimized inhibitors targeting the FP-family cysteine proteases of human malaria parasites.
PubMed: 35056641
DOI: 10.3390/microorganisms10010193 -
Annual Review of Microbiology Sep 2020African apes harbor at least twelve species, some of which have been a source of human infection. It is now well established that emerged following the transmission of... (Review)
Review
African apes harbor at least twelve species, some of which have been a source of human infection. It is now well established that emerged following the transmission of a gorilla parasite, perhaps within the last 10,000 years, while emerged earlier from a parasite lineage that infected humans and apes in Africa before the Duffy-negative mutation eliminated the parasite from humans there. Compared to their ape relatives, both human parasites have greatly reduced genetic diversity and an excess of nonsynonymous mutations, consistent with severe genetic bottlenecks followed by rapid population expansion. A putative new species widespread in chimpanzees, gorillas, and bonobos places the origin of in Africa. Here, we review what is known about the origins and evolutionary history of all human-infective species, the time and circumstances of their emergence, and the diversity, host specificity, and zoonotic potential of their ape counterparts.
Topics: Animals; DNA, Protozoan; Evolution, Molecular; Genetic Variation; Gorilla gorilla; Hominidae; Humans; Malaria; Pan troglodytes; Phylogeny; Plasmodium; Plasmodium falciparum; Zoonoses
PubMed: 32905751
DOI: 10.1146/annurev-micro-020518-115628 -
Frontiers in Microbiology 2022Malaria elimination includes neglected human malaria parasites spp., and . Biological features such as association with low-density infection and the formation of... (Review)
Review
Malaria elimination includes neglected human malaria parasites spp., and . Biological features such as association with low-density infection and the formation of hypnozoites responsible for relapse make their elimination challenging. Studies on these parasites rely primarily on clinical samples due to the lack of long-term culture techniques. With improved methods to enrich parasite DNA from clinical samples, whole-genome sequencing of the neglected malaria parasites has gained increasing popularity. Population genomics of more than 2200 global isolates has improved our knowledge of parasite biology and host-parasite interactions, identified vaccine targets and potential drug resistance markers, and provided a new way to track parasite migration and introduction and monitor the evolutionary response of local populations to elimination efforts. Here, we review advances in population genomics for neglected malaria parasites, discuss how the rich genomic information is being used to understand parasite biology and epidemiology, and explore opportunities for the applications of malaria genomic data in malaria elimination practice.
PubMed: 36160257
DOI: 10.3389/fmicb.2022.984394 -
Clinical Microbiology Reviews Oct 2007A review of the life history of Plasmodium malariae, the quartan malaria parasite of humans, is presented. Much of the information is based on data obtained from induced... (Review)
Review
A review of the life history of Plasmodium malariae, the quartan malaria parasite of humans, is presented. Much of the information is based on data obtained from induced infections in humans who were given malaria therapy for the treatment of neurosyphilis between 1940 and 1963. Prepatent periods (i.e., the time until the first day of parasite detection) fever episodes, and maximum parasitemias as a result of infection with P. malariae were obtained and are presented. Experimental and known vectors of the parasite are also discussed. Splenectomized chimpanzees and New World monkeys are readily infected and serve as sources of parasites and antigens for diagnostic and molecular studies. South American monkeys are naturally infected with a parasite known as Plasmodium brasilianum. This parasite appears to be P. malariae that has adapted from humans to grow in monkeys, probably within the last 500 years. Infection with P. malariae is associated with the production of immune complexes in the kidneys and the associated nephrotic syndrome. The essential lesions are a thickening of the glomerular basement membrane and endocapillary cell proliferation. Studies of monkeys infected with P. malariae indicate the same pathology as that demonstrated in humans.
Topics: Animals; Anopheles; Erythrocytes; Humans; Life Cycle Stages; Malaria; Plasmodium malariae
PubMed: 17934075
DOI: 10.1128/CMR.00027-07 -
Trends in Parasitology Jun 2007Although Plasmodium malariae was first described as an infectious disease of humans by Golgi in 1886 and Plasmodium ovale identified by Stevens in 1922, there are still... (Review)
Review
Although Plasmodium malariae was first described as an infectious disease of humans by Golgi in 1886 and Plasmodium ovale identified by Stevens in 1922, there are still large gaps in our knowledge of the importance of these infections as causes of malaria in different parts of the world. They have traditionally been thought of as mild illnesses that are caused by rare and, in case of P. ovale, short-lived parasites. However, recent advances in sensitive PCR diagnosis are causing a re-evaluation of this assumption. Low-level infection seems to be common across malaria-endemic areas, often as complex mixed infections. The potential interactions of P. malariae and P. ovale with Plasmodium falciparum and Plasmodium vivax might explain some basic questions of malaria epidemiology, and understanding these interactions could have an important influence on the deployment of interventions such as malaria vaccines.
Topics: Adolescent; Adult; Animals; Child; Child, Preschool; Humans; Infant; Infant, Newborn; Malaria; Microscopy; Plasmodium malariae; Plasmodium ovale; Polymerase Chain Reaction; Prevalence
PubMed: 17459775
DOI: 10.1016/j.pt.2007.04.009