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Journal of Vector Borne Diseases 2018Malaria, caused by the protozoan parasites of the genus Plasmodium, is a major health problem in many countries of the world. Five parasite species namely, Plasmodium... (Review)
Review
Malaria, caused by the protozoan parasites of the genus Plasmodium, is a major health problem in many countries of the world. Five parasite species namely, Plasmodium falciparum, P. vivax, P. malariae, P. ovale, and P. knowlesi, cause malaria in humans. Of these, P. falciparum and P. vivax are the most prevalent and account for the majority of the global malaria cases. In most areas of Africa, P. vivax infection is essentially absent because of the inherited lack of Duffy antigen receptor for chemokines on the surface of red blood cells that is involved in the parasite invasion of erythrocytes. Therefore, in Africa, most malaria infections are by P. falciparum and the highest burden of P. vivax infection is in Southeast Asia and South America. Plasmodium falciparum is the most virulent and as such, it is responsible for the majority of malarial mortality, particularly in Africa. Although, P. vivax infection has long been considered to be benign, recent studies have reported life-threatening consequences, including acute respiratory distress syndrome, cerebral malaria, multi-organ failure, dyserythropoiesis and anaemia. Despite exhibiting low parasite biomass in infected people due to parasite's specificity to infect only reticulocytes, P. vivax infection triggers higher inflammatory responses and exacerbated clinical symptoms than P. falciparum, such as fever and chills. Another characteristic feature of P. vivax infection, compared to P. falciparum infection, is persistence of the parasite as dormant liver-stage hypnozoites, causing recurrent episodes of malaria. This review article summarizes the published information on P. vivax epidemiology, drug resistance and pathophysiology.
Topics: Antimalarials; Asia, Southeastern; Drug Resistance; Female; Humans; Inflammation; Liver; Malaria, Vivax; Male; Plasmodium vivax; Pregnancy; Pregnancy Complications, Parasitic; Recurrence; South America
PubMed: 29916441
DOI: 10.4103/0972-9062.234620 -
Malaria Journal May 2022Malaria is a vector-borne disease caused by protozoan parasites of the genus Plasmodium. Plasmodium vivax is the most prevalent human-infecting species in the Americas.... (Review)
Review
Malaria is a vector-borne disease caused by protozoan parasites of the genus Plasmodium. Plasmodium vivax is the most prevalent human-infecting species in the Americas. However, the origins of this parasite in this continent are still debated. Similarly, it is now accepted that the existence of Plasmodium simium is explained by a P. vivax transfer from humans to monkey in America. However, many uncertainties still exist concerning the origin of the transfer and whether several transfers occurred. In this review, the most recent studies that addressed these questions using genetic and genomic approaches are presented.
Topics: Biological Evolution; Genome; Humans; Malaria; Plasmodium; Plasmodium vivax
PubMed: 35505431
DOI: 10.1186/s12936-022-04132-7 -
Pathogens and Global Health 2016The relapsing peculiarity of Plasmodium vivax is one of the prime reasons for sustained global malaria transmission. Global containment of P. vivax is more challenging... (Review)
Review
The relapsing peculiarity of Plasmodium vivax is one of the prime reasons for sustained global malaria transmission. Global containment of P. vivax is more challenging and crucial compared to other species for achieving total malaria control/elimination. Primaquine (PQ) failure and P. vivax relapse is a major global public health concern. Identification and characterization of different relapse strains of P. vivax prevalent across the globe should be one of the thrust areas in malaria research. Despite renewed and rising global concern by researchers on this once 'neglected' species, research and development on the very topic of P. vivax reappearance remains inadequate. Many malaria endemic countries have not mandated routine glucose-6-phosphate dehydrogenase (G6PD) testing before initiating PQ radical cure in P. vivax malaria. This results in either no PQ prescription or thoughtless prescription and administration of PQ to P. vivax patients by healthcare providers without being concerned about patients' G6PD status and associated complications. It is imperative to ascertain the G6PD status and optimum dissemination of PQ radical cure in all cases of P. vivax malaria across the globe. There persists a compelling need to develop/validate a rapid, easy-to-perform, easy-to-interpret, quality controllable, robust, and cost-effective G6PD assay. High-dose PQ of both standard and short duration appears to be safe and more effective for preventing relapses and should be practiced among patients with normal G6PD activity. Multicentric studies involving adequately representative populations across the globe with reference PQ dose must be carried out to determine the true distribution of PQ failure. Study proving role of cytochrome P450-2D6 gene in PQ metabolism and association of CYP2D6 metabolizer phenotypes and P. vivax relapse is of prime importance and should be carried forward in multicentric systems across the globe.
Topics: Antimalarials; Humans; Malaria, Vivax; Middle Aged; Plasmodium vivax; Primaquine; Recurrence; Treatment Outcome
PubMed: 27077309
DOI: 10.1080/20477724.2015.1133033 -
Cold Spring Harbor Perspectives in... Sep 2017is the second most prevalent cause of malaria worldwide and the leading cause of malaria outside of Africa. Although infections are seldom fatal clinical disease can be... (Review)
Review
is the second most prevalent cause of malaria worldwide and the leading cause of malaria outside of Africa. Although infections are seldom fatal clinical disease can be debilitating and imposes significant health and economic impacts on affected populations. Estimates of transmission and prevalence intensity can be problematic because many episodes of vivax originate from hypnozoite stages in the liver that have remained dormant from previous infections by an unknown mechanism. Lack of treatment options to clear hypnozoites and the ability to infect mosquitoes before disease symptoms present represent major challenges for control and eradication of vivax malaria. Compounding these challenges is the unique biology of and limited progress in development of experimental research tools, thereby hindering development of new drugs and vaccines. Renewed emphasis on vivax malaria research is beginning to make progress in overcoming some of these challenges.
Topics: Animals; Asymptomatic Infections; Humans; Malaria, Vivax; Plasmodium vivax
PubMed: 28490540
DOI: 10.1101/cshperspect.a025585 -
Malaria Journal May 2021Loop-mediated isothermal amplification (LAMP) for malaria diagnosis at the point of care (POC) depends on the detection capacity of synthesized nucleic acids and the...
BACKGROUND
Loop-mediated isothermal amplification (LAMP) for malaria diagnosis at the point of care (POC) depends on the detection capacity of synthesized nucleic acids and the specificity of the amplification target. To improve malaria diagnosis, new colorimetric LAMP tests were developed using multicopy targets for Plasmodium vivax and Plasmodium falciparum detection.
METHODS
The cytochrome oxidase I (COX1) mitochondrial gene and the non-coding sequence Pvr47 for P. vivax, and the sub-telomeric sequence of erythrocyte membrane protein 1 (EMP1) and the non-coding sequence Pfr364 for P. falciparum were targeted to design new LAMP primers. The limit of detection (LOD) of each colorimetric LAMP was established and assessed with DNA extracted by mini spin column kit and the Boil & Spin method from 28 microscopy infections, 101 malaria submicroscopic infections detected by real-time PCR only, and 183 negatives infections by both microscopy and PCR.
RESULTS
The LODs for the colorimetric LAMPs were estimated between 2.4 to 3.7 parasites/µL of whole blood. For P. vivax detection, the colorimetric LAMP using the COX1 target showed a better performance than the Pvr47 target, whereas the Pfr364 target was the most specific for P. falciparum detection. All microscopic infections of P. vivax were detected by PvCOX1-LAMP using the mini spin column kit DNA extraction method and 81% (17/21) were detected using Boil & Spin sample preparation. Moreover, all microscopic infections of P. falciparum were detected by Pfr364-LAMP using both sample preparation methods. In total, PvCOX1-LAMP and Pfr364-LAMP detected 80.2% (81 samples) of the submicroscopic infections using the DNA extraction method by mini spin column kit, while 36.6% (37 samples) were detected using the Boil & Spin sample preparation method.
CONCLUSION
The colorimetric LAMPs with multicopy targets using the COX1 target for P. vivax and the Pfr364 for P. falciparum have a high potential to improve POC malaria diagnosis detecting a greater number of submicroscopic Plasmodium infections.
Topics: Colorimetry; Electron Transport Complex IV; Malaria, Falciparum; Malaria, Vivax; Molecular Diagnostic Techniques; Nucleic Acid Amplification Techniques; Plasmodium falciparum; Plasmodium vivax; Protozoan Proteins
PubMed: 34011373
DOI: 10.1186/s12936-021-03753-8 -
The Journal of Infectious Diseases Oct 2021Plasmodium vivax malaria was thought to be rare in Africa, but an increasing number of P. vivax cases reported across Africa and in Duffy-negative individuals challenges...
Plasmodium vivax malaria was thought to be rare in Africa, but an increasing number of P. vivax cases reported across Africa and in Duffy-negative individuals challenges this dogma. The genetic characteristics of P. vivax in Duffy-negative infections, the transmission of P. vivax in East Africa, and the impact of environments on transmission remain largely unknown. This study examined genetic and transmission features of P. vivax from 107 Duffy-negative and 305 Duffy-positive individuals in Ethiopia and Sudan. No clear genetic differentiation was found in P. vivax between the 2 Duffy groups, indicating between-host transmission. P. vivax from Ethiopia and Sudan showed similar genetic clusters, except samples from Khartoum, possibly due to distance and road density that inhibited parasite gene flow. This study is the first to show that P. vivax can transmit to and from Duffy-negative individuals and provides critical insights into the spread of P. vivax in sub-Saharan Africa.
Topics: Africa, Eastern; Duffy Blood-Group System; Erythrocytes; Gene Pool; Genetic Variation; Humans; Malaria, Vivax; Plasmodium vivax; Receptors, Cell Surface; Sudan
PubMed: 33534886
DOI: 10.1093/infdis/jiab063 -
Antimicrobial Agents and Chemotherapy Aug 2017High-grade chloroquine (CQ) resistance has emerged in both and The aim of the present study was to investigate the phenotypic differences of CQ resistance in both of...
High-grade chloroquine (CQ) resistance has emerged in both and The aim of the present study was to investigate the phenotypic differences of CQ resistance in both of these species and the ability of known CQ resistance reversal agents (CQRRAs) to alter CQ susceptibility. Between April 2015 and April 2016, the potential of verapamil (VP), mibefradil (MF), L703,606 (L7), and primaquine (PQ) to reverse CQ resistance was assessed in 46 and 34 clinical isolates in Papua, Indonesia, where CQ resistance is present in both species, using a modified schizont maturation assay. In , CQ 50% inhibitory concentrations (ICs) were reduced when CQ was combined with VP (1.4-fold), MF (1.2-fold), L7 (4.2-fold), or PQ (1.8-fold). The degree of CQ resistance reversal in was highly correlated with CQ susceptibility for all CQRRAs ( = 0.951, 0.852, 0.962, and 0.901 for VP, MF, L7, and PQ, respectively), in line with observations in laboratory strains. In contrast, no reduction in the CQ ICs was observed with any of the CQRRAs in , even in those isolates with high chloroquine ICs. The differential effect of CQRRAs in and suggests significant differences in CQ kinetics and, potentially, the likely mechanism of CQ resistance between these two species.
Topics: Antimalarials; Chloroquine; Drug Resistance; Humans; Indonesia; Malaria, Falciparum; Malaria, Vivax; Parasitic Sensitivity Tests; Plasmodium falciparum; Plasmodium vivax
PubMed: 28533239
DOI: 10.1128/AAC.00355-17 -
Comptes Rendus Biologies Dec 2022Vivax malaria is an infectious disease caused by Plasmodium vivax, a parasitic protozoan transmitted by female Anopheline mosquitoes. Historically, vivax malaria has... (Review)
Review
Vivax malaria is an infectious disease caused by Plasmodium vivax, a parasitic protozoan transmitted by female Anopheline mosquitoes. Historically, vivax malaria has often been regarded as a benign self-limiting infection due to the observation of low parasitemia in Duffy-positive patients in endemic transmission areas and the virtual absence of infections in Duffy-negative individuals in Sub Saharan Africa. However, the latest estimates show that the burden of the disease is not decreasing in many countries and cases of vivax infections in Duffy-negative individuals are increasingly reported throughout Africa. This raised questions about the accuracy of diagnostics and the evolution of interactions between humans and parasites. For a long time, our knowledge on P. vivax biology has been hampered due to the limited access to biological material and the lack of robust in vitro culture methods. Consequently, little is currently known about P. vivax blood stage invasion mechanisms. The introduction of omics technologies with novel and accessible techniques such as third generation sequencing and RNA sequencing at single cell level, two-dimensional electrophoresis, liquid chromatography, and mass spectrometry, has progressively improved our understanding of P. vivax genetics, transcripts, and proteins. This review aims to provide broad insights into P. vivax invasion mechanisms generated by genomics, transcriptomics, and proteomics and to illustrate the importance of integrated multi-omics studies.
Topics: Animals; Humans; Female; Plasmodium vivax; Malaria, Vivax; Protozoan Proteins; Receptors, Cell Surface; Africa
PubMed: 36847467
DOI: 10.5802/crbiol.95 -
PLoS Neglected Tropical Diseases Mar 2020More than 200 million malaria clinical cases are reported each year due to Plasmodium vivax, the most widespread Plasmodium species in the world. This species has been...
More than 200 million malaria clinical cases are reported each year due to Plasmodium vivax, the most widespread Plasmodium species in the world. This species has been neglected and understudied for a long time, due to its lower mortality in comparison with Plasmodium falciparum. A renewed interest has emerged in the past decade with the discovery of antimalarial drug resistance and of severe and even fatal human cases. Nonetheless, today there are still significant gaps in our understanding of the population genetics and evolutionary history of P. vivax, particularly because of a lack of genetic data from Africa. To address these gaps, we genotyped 14 microsatellite loci in 834 samples obtained from 28 locations in 20 countries from around the world. We discuss the worldwide population genetic structure and diversity and the evolutionary origin of P. vivax in the world and its introduction into the Americas. This study demonstrates the importance of conducting genome-wide analyses of P. vivax in order to unravel its complex evolutionary history.
Topics: Genetic Variation; Genotype; Genotyping Techniques; Global Health; Humans; Malaria, Vivax; Plasmodium vivax
PubMed: 32150544
DOI: 10.1371/journal.pntd.0008072 -
Current Opinion in Microbiology Dec 2018Plasmodium vivax is uniquely restricted to invading reticulocytes, the youngest of red blood cells. Parasite invasion relies on the sequential deployment of multiple... (Review)
Review
Plasmodium vivax is uniquely restricted to invading reticulocytes, the youngest of red blood cells. Parasite invasion relies on the sequential deployment of multiple parasite invasion ligands. Correct targeting of the host reticulocyte is mediated by two families of invasion ligands: the reticulocyte binding proteins (RBPs) and erythrocyte binding proteins (EBPs). The Duffy receptor has long been established as a key determinant for P. vivax invasion. However, recently, the RBP protein PvRBP2b has been shown to bind to transferrin receptor, which is expressed on reticulocytes but lost on normocytes, implicating the ligand-receptor in the reticulocyte tropism of P. vivax. Furthermore there is increasing evidence for P. vivax growth and sexual development in reticulocyte-enriched tissues such as the bone marrow.
Topics: Animals; Host-Parasite Interactions; Humans; Malaria, Vivax; Plasmodium vivax; Protozoan Proteins; Reticulocytes; Tropism
PubMed: 30366310
DOI: 10.1016/j.mib.2018.10.002