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Malaria Journal Dec 2012Plasmodium vivax has traditionally been considered virtually absent from Western and Central Africa, due to the absence of the Duffy blood group in most of the...
BACKGROUND
Plasmodium vivax has traditionally been considered virtually absent from Western and Central Africa, due to the absence of the Duffy blood group in most of the population living in these areas. Recent reports, however, suggest the circulation of P. vivax in sub-Saharan Africa.
METHODS
Giemsa/Field-stained smears from febrile patients recruited in five different cities (Goundam, Tombouctou, Gao, Bourem and Kidal) pertaining to three regions from Northern Mali were examined. Nested-PCR and DNA sequence analyses of selected samples were performed to fully confirm the presence of P. vivax infections.
RESULTS
Results demonstrated the presence of P. vivax infections in close to 30% of the cases as detected by Giemsa/Field-stained smears and nested-PCR and DNA-sequence analyses of selected samples unequivocally confirmed the presence of P. vivax.
CONCLUSIONS
The diagnostics of this human malaria parasite should be taken into account in the context of malaria control and elimination efforts, not only in Mali, but also in sub-Saharan Africa.
Topics: DNA, Protozoan; Duffy Blood-Group System; Humans; Malaria, Vivax; Mali; Molecular Epidemiology; Phylogeny; Plasmodium vivax; Polymerase Chain Reaction; RNA, Protozoan
PubMed: 23217064
DOI: 10.1186/1475-2875-11-405 -
The Journal of Infectious Diseases Oct 2019The Horn of Africa harbors the largest reservoir of Plasmodium vivax in the continent. Most of sub-Saharan Africa has remained relatively vivax-free due to a high...
The Horn of Africa harbors the largest reservoir of Plasmodium vivax in the continent. Most of sub-Saharan Africa has remained relatively vivax-free due to a high prevalence of the human Duffy-negative trait, but the emergence of strains able to invade Duffy-negative reticulocytes poses a major public health threat. We undertook the first population genomic investigation of P. vivax from the region, comparing the genomes of 24 Ethiopian isolates against data from Southeast Asia to identify important local adaptions. The prevalence of the Duffy binding protein amplification in Ethiopia was 79%, potentially reflecting adaptation to Duffy negativity. There was also evidence of selection in a region upstream of the chloroquine resistance transporter, a putative chloroquine-resistance determinant. Strong signals of selection were observed in genes involved in immune evasion and regulation of gene expression, highlighting the need for a multifaceted intervention approach to combat P. vivax in the region.
Topics: Adaptation, Biological; Adolescent; Animals; Child; Child, Preschool; Ethiopia; Female; Genotype; Humans; Infant; Infant, Newborn; Malaria, Vivax; Male; Plasmodium vivax; Prevalence; Selection, Genetic
PubMed: 30668735
DOI: 10.1093/infdis/jiz016 -
The Journal of Infectious Diseases Apr 2007
Topics: Animals; Genotype; Humans; Malaria, Vivax; Plasmodium vivax; Recurrence
PubMed: 17330778
DOI: 10.1086/512246 -
MBio May 2018causes heavy burdens of disease across malarious regions worldwide. Mature asexual and transmissive gametocyte stages occur in the blood circulation, and it is often...
causes heavy burdens of disease across malarious regions worldwide. Mature asexual and transmissive gametocyte stages occur in the blood circulation, and it is often assumed that accumulation/sequestration in tissues is not an important phase in their development. Here, we present a systematic study of stage distributions in infected tissues of nonhuman primate (NHP) malaria models as well as in blood from human infections. In a comparative analysis of the transcriptomes of and blood-stage parasites, we found a conserved cascade of stage-specific gene expression despite the greatly different gametocyte maturity times of these two species. Using this knowledge, we validated a set of conserved asexual- and gametocyte-stage markers both by quantitative real-time PCR and by antibody assays of peripheral blood samples from infected patients and NHP ( sp.). Histological analyses of parasites in organs of 13 infected NHP ( and species) demonstrated a major fraction of immature gametocytes in the parenchyma of the bone marrow, while asexual schizont forms were enriched to a somewhat lesser extent in this region of the bone marrow as well as in sinusoids of the liver. These findings suggest that the bone marrow is an important reservoir for gametocyte development and proliferation of malaria parasites. malaria continues to cause major public health burdens worldwide. Yet, significant knowledge gaps in the basic biology and epidemiology of malaria remain, largely due to limited available tools for research and diagnostics. Here, we present a systematic examination of tissue sequestration during infection. Studies of nonhuman primates and malaria patients revealed enrichment of developing sexual stages (gametocytes) and mature replicative stages (schizonts) in the bone marrow and liver, relative to those present in peripheral blood. Identification of the bone marrow as a major tissue reservoir has important implications for parasite diagnosis and treatment.
Topics: Animals; Aotidae; Bone Marrow; Female; Humans; Malaria, Falciparum; Malaria, Vivax; Male; Plasmodium falciparum; Plasmodium vivax; Protozoan Proteins; Saimiri
PubMed: 29739900
DOI: 10.1128/mBio.00625-18 -
Proteomics. Clinical Applications Jul 2018Plasmodium vivax is the most geographically widespread species responsible for malaria in humans. Our study focused on identifying highly expressed parasite proteins...
Plasmodium vivax is the most geographically widespread species responsible for malaria in humans. Our study focused on identifying highly expressed parasite proteins using a shotgun proteomics approach. Parasites (P. vivax) are isolated from seven patient samples using saponin lysis. Protein extracts from these parasites are processed and subjected to LC-MS/MS analysis. An overall proteome coverage of 605 P. vivax proteins along with 1670 human host proteins are obtained upon combining the data from LC-MS/MS runs. While a major proportion of the P. vivax proteins are either hypothetical or involved in basic cellular activities, few proteins such as tryptophan-rich antigen (Pv-fam-a; PVX_090265), Pv-fam-d protein (PVX_101520), Plasmodium exported protein (PVX_003545), Pvstp1 (PVX_094303) and hypothetical protein (PVX_083555) are detected in more than 80% of the clinical isolates and found to be unique to P. vivax without orthologs in P. falciparum. Our proteomics study on individual parasite isolates reveals highly expressed P. vivax proteins, few of which may be good candidates for vivax malaria diagnosis due to their abundance and absence in P. falciparum. This study represents the first step towards the identification of biomarkers for P. vivax malaria. In future, their clinical diagnostic values must be explored and validated on large patient cohorts.
Topics: Biomarkers; Humans; India; Malaria, Vivax; Plasmodium vivax; Proteome; Proteomics; Protozoan Proteins
PubMed: 28841253
DOI: 10.1002/prca.201700046 -
Malaria Journal Feb 2008Four of five Plasmodium species infecting humans are present in Madagascar. Plasmodium vivax remains the second most prevalent species, but is understudied. No data is...
BACKGROUND
Four of five Plasmodium species infecting humans are present in Madagascar. Plasmodium vivax remains the second most prevalent species, but is understudied. No data is available on its susceptibility to sulphadoxine-pyrimethamine, the drug recommended for intermittent preventive treatment during pregnancy. In this study, the prevalence of P. vivax infection and the polymorphisms in the pvdhfr and pvdhps genes were investigated. The correlation between these polymorphisms and clinical and parasitological responses was also investigated in P. vivax-infected patients.
METHODS
Plasmodium vivax clinical isolates were collected in eight sentinel sites from the four major epidemiological areas for malaria across Madagascar in 2006/2007. Pvdhfr and pvdhps genes were sequenced for polymorphism analysis. The therapeutic efficacy of SP in P. vivax infections was assessed in Tsiroanomandidy, in the foothill of the central highlands. An intention-to-treat analysis of treatment outcome was carried out.
RESULTS
A total of 159 P. vivax samples were sequenced in the pvdhfr/pvdhps genes. Mutant-types in pvdhfr gene were found in 71% of samples, and in pvdhps gene in 16% of samples. Six non-synonymous mutations were identified in pvdhfr, including two novel mutations at codons 21 and 130. For pvdhps, beside the known mutation at codon 383, a new one was found at codon 422. For the two genes, different combinations were ranged from wild-type to quadruple mutant-type. Among the 16 patients enrolled in the sulphadoxine-pyrimethamine clinical trial (28 days of follow-up) and after adjustment by genotyping, 3 (19%, 95% CI: 5%-43%) of them were classified as treatment failure and were pvdhfr 58R/117N double mutant carriers with or without the pvdhps 383G mutation.
CONCLUSION
This study highlights (i) that genotyping in the pvdhfr and pvdhps genes remains a useful tool to monitor the emergence and the spread of P. vivax sulphadoxine-pyrimethamine resistant in order to improve the national antimalarial drug policy, (ii) the issue of using sulphadoxine-pyrimethamine as a monotherapy for intermittent preventive treatment of pregnant women or children.
Topics: Adolescent; Adult; Animals; Antimalarials; Child; Child, Preschool; Dihydropteroate Synthase; Drug Combinations; Drug Resistance; Female; Humans; Infant; Madagascar; Malaria, Vivax; Male; Molecular Sequence Data; Mutation; Plasmodium vivax; Polymerase Chain Reaction; Polymorphism, Genetic; Protozoan Proteins; Pyrimethamine; Sequence Analysis, DNA; Sulfadoxine; Tetrahydrofolate Dehydrogenase; Treatment Outcome
PubMed: 18302746
DOI: 10.1186/1475-2875-7-35 -
Biochemical and Biophysical Research... Nov 2004Plasmodium vivax, one of the four parasite species causing malaria in humans, is the most widespread throughout the world, leading to nearly 80 million cases per year,...
Plasmodium vivax, one of the four parasite species causing malaria in humans, is the most widespread throughout the world, leading to nearly 80 million cases per year, mainly in Latin-America and Asia. An open reading frame encoding the Plasmodium falciparum merozoite surface protein 8 P. vivax homologue has been identified in the present study by screening the current data obtained from this parasite's partially sequenced genome. This new protein contains 487 amino-acids, two epidermal growth factor like domains, hydrophobic regions at the N- and C-termini compatible with a signal peptide, and a glycosylphosphatidylinositol anchor site, respectively. This gene's transcription and its encoded protein expression have been assessed, as well as its recognition by P. vivax-infected patients' sera. Based on this recognition, and a previous study showing that mice immunised with the Plasmodium yoelii homologous protein were protected, we consider the PvMSP8 a good candidate to be included in a multi-stage multi-antigen P. vivax vaccine.
Topics: Amino Acid Motifs; Amino Acid Sequence; Animals; Antibodies, Protozoan; Antigens, Protozoan; Cloning, Molecular; Epidermal Growth Factor; Gene Expression; Humans; Molecular Sequence Data; Plasmodium vivax; Protozoan Proteins
PubMed: 15504368
DOI: 10.1016/j.bbrc.2004.09.202 -
Salud Publica de Mexico 2020To research mutations associated to pyrimethamine resistance in dihydrofolate reductase (pvdhfr) of Plasmodium vivax from Mexico and Nicaragua and compare it to that...
OBJECTIVE
To research mutations associated to pyrimethamine resistance in dihydrofolate reductase (pvdhfr) of Plasmodium vivax from Mexico and Nicaragua and compare it to that reported in the rest of America.
MATERIALS AND METHODS
Genomic DNA was obtained from P. vivax-infected blood samples. A pvdhfr gene fragment was amplified and sequenced. The identified gene variations were compared to those observed in other affected sites of America.
RESULTS
No mutations in pvdhfr were detected in P. vivax from Mexico and Nicaragua. One synonymous change and variation in the repeat domain was detected in Nicaraguan parasites. In South America, a high frequency of variant residues 58R and 117N associated to pyrimethamine resistance was reported.
CONCLUSIONS
The lack of polymorphisms associated with pyrimethamine resistance suggests that drug-resistant P. vivax has not penetrated Mesoamerica, nor have local parasites been under selective pressure. These data contribute to establish the basis for the epidemiological surveillance of drug resistance.
Topics: Antiprotozoal Agents; Brazil; Colombia; French Guiana; Genetic Variation; Honduras; Humans; Insecticide Resistance; Mexico; Mutation; Nicaragua; Plasmodium vivax; Pyrimethamine; South America; Tetrahydrofolate Dehydrogenase
PubMed: 32516871
DOI: 10.21149/10129 -
BMC Evolutionary Biology Feb 2012Plasmodium vivax is the most widely distributed human malaria parasite outside of Africa, and its range extends well into the temperate zones. Previous studies provided...
BACKGROUND
Plasmodium vivax is the most widely distributed human malaria parasite outside of Africa, and its range extends well into the temperate zones. Previous studies provided evidence for vivax population differentiation, but temperate vivax parasites were not well represented in these analyses. Here we address this deficit by using complete mitochondrial (mt) genome sequences to elucidate the broad genetic diversity and population structure of P. vivax from temperate regions in East and Southeast Asia.
RESULTS
From the complete mtDNA sequences of 99 clinical samples collected in China, Myanmar and Korea, a total of 30 different haplotypes were identified from 26 polymorphic sites. Significant differentiation between different East and Southeast Asian parasite populations was observed except for the comparison between populations from Korea and southern China. Haplotype patterns and structure diversity analysis showed coexistence of two different groups in East Asia, which were genetically related to the Southeast Asian population and Myanmar population, respectively. The demographic history of P. vivax, examined using neutrality tests and mismatch distribution analyses, revealed population expansion events across the entire P. vivax range and the Myanmar population. Bayesian skyline analysis further supported the occurrence of ancient P. vivax population expansion.
CONCLUSIONS
This study provided further resolution of the population structure and evolution of P. vivax, especially in temperate/warm-temperate endemic areas of Asia. The results revealed divergence of the P. vivax populations in temperate regions of China and Korea from other populations. Multiple analyses confirmed ancient population expansion of this parasite. The extensive genetic diversity of the P. vivax populations is consistent with phenotypic plasticity of the parasites, which has implications for malaria control.
Topics: Asia; China; Genetic Variation; Genome, Mitochondrial; Humans; Malaria, Vivax; Myanmar; Plasmodium vivax; Polymorphism, Single Nucleotide; Republic of Korea
PubMed: 22340143
DOI: 10.1186/1471-2148-12-22 -
Memorias Do Instituto Oswaldo Cruz Feb 2009The naturally occurring clonal diversity among field isolates of the major human malaria parasite Plasmodium vivax remained unexplored until the early 1990s, when... (Review)
Review
The naturally occurring clonal diversity among field isolates of the major human malaria parasite Plasmodium vivax remained unexplored until the early 1990s, when improved molecular methods allowed the use of blood samples obtained directly from patients, without prior in vitro culture, for genotyping purposes. Here we briefly review the molecular strategies currently used to detect genetically distinct clones in patient-derived P. vivax samples, present evidence that multiple-clone P. vivax infections are commonly detected in areas with different levels of malaria transmission and discuss possible evolutionary and epidemiological consequences of the competition between genetically distinct clones in natural human infections. We suggest that, when two or more genetically distinct clones are present in the same host, intra-host competition for limited resources may select for P. vivax traits that represent major public health challenges, such as increased virulence, increased transmissibility and antimalarial drug resistance.
Topics: Alleles; Animals; Genotype; Humans; Malaria, Vivax; Microsatellite Repeats; Plasmodium vivax; Prevalence
PubMed: 19274379
DOI: 10.1590/s0074-02762009000100011