Background: Plasmodium vivax is the second most common species among malaria patients diagnosed in Europe, but epidemiological and clinical data on imported P. vivax malaria are limited. The TropNetEurop surveillance network has monitored the importation of vivax malaria into Europe since 1999. Objectives: To present epidemiological and clinical data on imported P. vivax malaria collected at European level. Material and methods: Data of primary cases of P. vivax malaria reported between January 1999 and September 2003 were analysed, focusing on disease frequency, patient characteristics, place of infection, course of disease, treatment and differences between network-member countries. Results: Within the surveillance period 4,801 cases of imported malaria were reported. 618 (12.9%) were attributed to P. vivax. European travellers and immigrants were the largest patient groups, but their proportion varied among the reporting countries. The main regions of infection in descending order were the ...
Plasmodium vivax accounts for about 44 % of all malaria infection in Ethiopia. Chloroquine (CQ) is the first-line treatment for vivax malaria in Ethiopia. Chloroquine-resistant (CQR) P. vivax has been emerging in different parts of the world to compromise the efficacy of the drug and pose both health and economic impact in the developing world. The current study was aimed at assessing the therapeutic efficacy of CQ for the treatment of vivax malaria among outpatients at Hossana Health Care Centre, southern Ethiopia. A one-arm, 28-day follow-up, in vivo therapeutic efficacy study was conducted from 5 April to 25 June, 2014. Sixty-three patients aged between four and 59 years were enrolled with microscopically confirmed P. vivax infection. All patients were treated with CQ 25 mg/kg for 3 days. Recurrence of parasitaemia and clinical conditions of patients were assessed on days 1, 2, 3, 7, 14, 21, and 28 during the 28-day follow-up period. Haemoglobin (Hb) level was determined
Plasmodium vivax is a major cause of illness in areas with low transmission of malaria in Latin America, Asia, and the Horn of Africa. However, pregnancy-associated malaria remains poorly characterized in such areas. Using a hospital-based survey of women giving birth and an antenatal survey, we assessed the prevalence rates of Plasmodium spp. infections in pregnant women in Bolivia, and evaluated the consequences of malaria during pregnancy on the health of mothers and newborns. P. vivax infection was detected in 7.9% of pregnant women attending antenatal visits, and placental infection occurred in 2.8% of deliveries; these rates did not vary with parity. Forty-two percent of all P. vivax malaria episodes were symptomatic. P. vivax-infected pregnant women were frequently anemic (6.5%) and delivered babies of reduced birthweight. P. vivax infections during pregnancy are clearly associated with serious adverse outcomes and should be considered in prevention strategies of pregnancy-associated malaria.
Recent findings: Studies from Indonesia, Papua New Guinea, Thailand and India have shown that 21-27% of patients with severe malaria have P. vivax monoinfection. The clinical spectrum of these cases is broad with an overall mortality of 0.8-1.6%. Major manifestations include severe anaemia and respiratory distress, with infants being particularly vulnerable. Most reports of severe and fatal vivax malaria come from endemic regions where populations have limited access to healthcare, a high prevalence of comorbidity and where drug-resistant P. vivax strains and partially effective primaquine regimens significantly undermine the radical cure and control of this relapsing infection. The mechanisms underlying severe disease in vivax malaria remain poorly defined ...
Identification of risk factors is important for the establishment of malaria elimination programmes tailored to specific regions. Type of house construction had been associated with increasing risk of acquiring malaria. This study aimed at establishing the association between determinants of low socio-economic status (SES) and type of house construction with the likelihood of living in a Plasmodium vivax malarious corregimiento (smallest political division) in Panama during 2009-2012. To determine the association between type-2 houses (build with deciduous materials) and other determinants of low SES, with living in a malarious corregimiento, this study analyzed demographic and housing census data (2010), and malaria incidence aggregated at the corregimiento level (2009-2012), using a Spearmans non-parametric correlation test to explore for associations, followed by a case-control study and a reduced multivariate logistic regression approach for confirmation. A descriptive temporal and spatial analysis
Among the surface-exposed antigens of the malaria parasite, those with known essential functions that can be disrupted by antibodies represent the most promising candidates for development as malaria vaccines. Two recombinant protein subunits of the Plasmodium vivax merozoite surface protein 1 have been shown to bind to reticulocytes in enzyme-linked immunosorbent assays. This article discusses the importance of such pre-clinical analyses in the validation of candidate vaccine molecules for P. vivax, given the constraints imposed by the use of primate models and the cost of producing suitable material for human trials.. ...
1. TjitraEAnsteyNMSugiartoPWarikarNKenangalemE. 2008. Multidrug-resistant Plasmodium vivax associated with severe and fatal malaria. A prospective study in Papua, Indonesia.. PLoS Med. 5. e128. doi:10.1371/journal.pmed.0050128. 2. GentonBDAcremontVRareLBaeaKReederJC. 2008. Plasmodium vivax and mixed infections are associated with severe malaria in children: A prospective cohort study from Papua New Guinea.. PLoS Med. 5. e127. doi:10.1371/journal.pmed.0050127. 3. BejonPBerkleyJAMwangiTOgadaEMwangiI. 2007. Defining childhood severe falciparum malaria for intervention studies.. PLoS Med. 4. e251. doi:10.1371/journal.pmed.0040251. 4. MayxayMPukrittayakameeSNewtonPNWhiteNJ. 2004. Mixed-species malaria infections in humans.. Trends Parasitol. 20. 233. 240. 5. RatcliffASiswantoroHKenangalemEMaristelaRWuwungRM. 2007. Two fixed-dose artemisinin combinations for drug-resistant falciparum and vivax malaria in Papua, Indonesia: An open-label randomised comparison.. Lancet. 369. 757. 765. 6. ...
Malaria incidence data at the district level from 1997 to 2002 and total malaria case data from 1965 to 2002 in Thailand were analyzed to determine the spatial and temporal dynamics of Plasmodium falciparum and P. vivax malaria incidence. Over the 37-year period, there was a 35-fold reduction in the incidence rates of P. falciparum malaria (11.86% in 1965 versus 0.34% in 2002) and a 7-fold reduction in P. vivax malaria (2.89% in 1965 versus 0.40% in 2002). The incidence ratio of P. falciparum to P. vivax malaria was reduced from 4.1 to 0.8 during this period. Malaria incidence rate exhibited the most rapid reduction between 1975 and 1985, coinciding with the introduction of a combination of antifolate drugs (sulfadoxine-pyrimethamine). The distribution maps of P. falciparum and P. vivax malaria incidence rates indicated a high spatial heterogeneity. The Thailand-Myanmar and Thailand-Cambodia border areas, where migration of foreign workers was pronounced, had the highest incidence rates for P.
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FIGUEIREDO FILHO, Alberto Ferreira et al. Desempenho de um teste de imunocromatografia para malária por P. vivax na Amazônia. Rev. Saúde Pública [online]. 2003, vol.37, n.3, pp.390-392. ISSN 1518-8787. http://dx.doi.org/10.1590/S0034-89102003000300021.. Avaliação do teste ICT malaria Pf/PvTM para o diagnóstico da malária por P. vivax em Belém, Estado do Pará. Foram comparados os resultados do teste imunocromatográfico com a gota espessa (GE) e avaliados o comportamento desse teste, estocado a três temperaturas distintas (250C/ 300C/ 370C), 24 horas antes de seu uso. A sensibilidade do ICT malaria Pf/PvTM foi de 61,8% com especificidade de 100%, valores preditivo positivo e negativo de 100% e 71,8%, respectivamente, e acurácia de 80,67%. A sensibilidade desse teste foi independente da densidade parasitária. Este teste necessita de reavaliação para melhorar o seu comportamento no diagnóstico da malária por P. vivax.. Keywords : Malária vivax [diagnóstico]; Plasmodium vivax; ...
Review on the effect of the drug tafenoquine on clearing the dormant P. vivax parasites in infected patients to prevent a relapse
This proposal is the first renewal of our training program entitled Enhancing vivax malaria research in Thailand (D43TW006571). Plasmodium vivax is a highly pre...
Human plasmodial malaria is a severe infection of the erythrocytes with significantmorbidity and mortality. The dimensional changes induced by P.vivax malaria parasites in erythrocytesin human blood are prominent and varies with the degree of parasitaemia. Aggregation of erythrocytesis a common finding in patients infected with malaria.The changes in the shape of erythrocyte and its cytoplasm have been determined by shapedescriptors and gray scale variation of the cytoplasm by microscopic imaging and image processingtools. The computerized shape analysis is carried out from the digital images obtained undermicroscope by shape descriptors based on projected area, perimeter and form factor,as measured byprocessing of images of erythrocytes in patients undergoing treatment for malaria. The changes inducedin the cytoplasm by the malaria parasite are determined by the scanning of erythrocytes images alongthe horizontal diameter. The levels of aggregation of erythrocytes corresponding to the levels
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Stephen Rogerson and Richard Carter discuss two new studies that challenge current dogma by suggesting that vivax malaria can cause severe disease.
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Rosette formation is one of the unique biological phenomena that have been linked to pathobiology of malaria. It is believe to be associated with the severe outcomes of falciparum malaria. Most of the knowledge about rosetting is obtained from in-depth studies conducted on Plasmodium falciparum. However, the rosetting phenomenon and pathobiology of vivax malaria is not well studied. This research project aimed at deciphering the unknown aspects behind rosetting phenomenon of P. vivax, and investigating the role of rosette formation in pathobiology of vivax malaria. In total, 121 fresh P. vivax isolates, 48 cryopreserved P. vivax isolates, 122 fresh P. falciparum isolates and 5 cryopreserved P. falciparum isolates were recruited into this research project. A novel technique suitable for reticulocyte characterization and rosetting assay in field setting was developed from this research project. Based on the field studies conducted, rosette formation is common in P. vivax. However, rosetting is not ...
Extracellular vesicles (EVs) play a role in the pathogenesis of malaria vivax, according to a study led by researchers from the Barcelona Institute for Global Health (ISGlobal) and the Germans Trias i Pujol Health Science Research Institute (IGTP). The findings, published in Nature Communications, indicate that EVs from P. vivax patients communicate with spleen fibroblasts promoting the adhesion of parasite-infected red blood cells. These data provide important insights into the pathology of vivax malaria.
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Purpose is to assess the efficacy of pyronaridine-artesunate against P. vivax malaria to support updating of the national policy. The study will be conducted from September to December 2018 in both study sites. It is a one arm prospective evaluation of clinical and parasitological responses to directly observed treatment for uncomplicated malaria. People with uncomplicated malaria who meet the study inclusion criteria will be enrolled, treated on site with pyronaridine-artesunate for uncomplicated P. vivax malaria and monitored for 28 days. Total 140 (70 patients for each study site) will be included ...
The malaria species rampant in the Asia-Pacific region has been a significant driver of evolution of the human genome, a new study has shown. An international team of researchers has shown that Plasmodium vivax malaria, the ...
GlaxoSmithKline and the Medicines for Malaria Venture are seeking permission to market single-dose tafenoquine in the US to prevent relapse of Plasmodium vivax malaria. - News - PharmaTimes
FIND officials recently released a summary about a meeting held in Philadelphia last fall where they discussed creating new diagnostic solutions for Plasmodium vivax malaria.
GRK2 expression is enhanced in neutrophils during acute malaria.Neutrophils isolated from P. vivax-infected patients (closed circles; n = 11) or healthy don
Anstey, Nicholas M., Auburn , Sarah, Baird, J. Kevin, Battle, Katherine E., Bobogare, Albino, Chancellor , Arna , Chasombat , Sanchai, Cheng , Qin, Domingo, Gonzalo J. , Drakeley , Christopher J., Drukpa, Tobgyel, Dysoley, Lek, Fe Esperanza, Espino, Gething, Peter W., Ghimire, Prakash, Gosling, Roly D., Grewal-Daumerie, Penny, Hay, Simon I., Howes, Rosalind E., Hwang, Jimee, Karim, Jahirul , Khan, Wasif Ali , Kim, Jung-Yeon , Ley, Benedikt , Mannion, Kylie, McCarthy, James, Keong, Wan Ming , Mueller, Ivo, Namgay, Rinzin , Price, Ric N., Qi, Gao , Rebueno, Marvi , Reeder, John, Richards, Jack, Sattabongkot-Prachumsri, Jetsumon , Shanks, G. Dennis , Sibley, Carol Hopkins , Surya, Asik , Taleo, George , Thang, Ngo Duc , Thongpaseuth, Vonethalom , Thriemer, Kamala , Trimarsanto, Hidayat , Vestergaard, Lasse S., von Seidelein, Lorenz , and Whittaker, Maxine (2015) Targeting vivax malaria in the Asia Pacific: the Asia Pacific malaria elimination network vivax working group. Malaria Journal, ...
Plasmodium vivax merozoite surface protein-1 paralog (PvMSP1P) is a glycosylphosphatidylinositol-anchored protein expressed on the merozoite surface. This molecule is a target of natural immunity, as high anti-MSP1P-19 antibody levels were detected during P. vivax infection and the antibody inhibited PvMSP1P-erythrocyte binding. Recombinant PvMSP1P antigen results in production of a significant Th1 cytokine response in immunized mice. The present study was performed to characterize natural cellular immunity against PvMSP1P-19 and PvDBP region II in acute and recovery P. vivax infection. Peripheral blood mononuclear cells (PBMCs) from acute and recovery P. vivax infection were obtained for lymphocyte proliferation assay upon PvMSP1P-19 and PvDBP region II antigen stimulation. The culture supernatant was examined for the presence of the cytokines IL-2, TNF, IFN-γ and IL-10 by enzyme-linked immunosorbent assay (ELISA). To determine whether Th1 or Th2 have a memory response against PvMSP1P-19 and PvDBPII
The aim of this study was to develop a simple, field-practical, and effective in vitro method for determining the sensitivity of fresh erythrocytic Plasmodium vivax isolates to a range of antimalarials. The method used is a modification of the standard World Health Organization (WHO) microtest for determination of P. falciparum drug sensitivity. The WHO method was modified by removing leukocytes and using a growth medium supplemented with AB(+) serum. We successfully carried out 34 in vitro drug assays on 39 P. vivax isolates collected from the Mae Sod malaria clinic, Tak Province, Thailand. The mean percentage of parasites maturing to schizonts (six or more merozoites) in control wells was 66.5% +/- 5.9% (standard deviation). This level of growth in the control wells enabled rapid microscopic determination (5 min per isolate per drug) of the MICs of chloroquine, dihydroartemisinin, WR238605 (tafenoquine), and sulfadoxine. P. vivax was relatively sensitive to chloroquine (MIC = 160 ng/ml, 50% inhibitory
Plasmodium vivax threatens nearly half the worlds population and is a significant impediment to achievement of the millennium development goals. It is an important, but incompletely understood, cause of anaemia. This review synthesizes current evidence on the epidemiology, pathogenesis, treatment and consequences of vivax-associated anaemia. Young children are at high risk of clinically significant and potentially severe vivax-associated anaemia, particularly in countries where transmission is intense and relapses are frequent. Despite reaching lower densities than Plasmodium falciparum, Plasmodium vivax causes similar absolute reduction in red blood cell mass because it results in proportionately greater removal of uninfected red blood cells. Severe vivax anaemia is associated with substantial indirect mortality and morbidity through impaired resilience to co-morbidities, obstetric complications and requirement for blood transfusion. Anaemia can be averted by early and effective anti-malarial ...
Annually, an estimated 219 million people are infected with malaria and the disease is endemic in 104 countries[1]. Plasmodium falciparum malaria is associated with the highest mortality and is accordingly prioritized in research and control. Another species, Plasmodium vivax, has gained less scientific attention despite being the most widely distributed malaria species endemic in tropical and subtropical countries worldwide, with an estimated 2.8 billion people currently at risk[2-4]. It is estimated that at least 130 million people are infected with P. vivax annually[5], causing significant economic and financial burden to affected countries[6].. In historic Europe, P. vivax malaria was endemic in many countries, reaching as far as Finland and England in the north[6, 7]. Malaria disappeared from Europe in the mid-20th Century, likely as a result of a combination of various factors, including improved housing conditions, better health care services, and the implementation of various malaria ...
The incidence of Plasmodium vivax infection has declined markedly in Malaysia over the past decade despite evidence of high-grade chloroquine resistance. Here we investigate the genetic changes in a P. vivax population approaching elimination in 51 isolates from Sabah, Malaysia and compare these with data from 104 isolates from Thailand and 104 isolates from Indonesia. Sabah displays extensive population structure, mirroring that previously seen with the emergence of artemisinin-resistant P. falciparum founder populations in Cambodia. Fifty-four percent of the Sabah isolates have identical genomes, consistent with a rapid clonal expansion. Across Sabah, there is a high prevalence of loci known to be associated with antimalarial drug resistance. Measures of differentiation between the three countries reveal several gene regions under putative selection in Sabah. Our findings highlight important factors pertinent to parasite resurgence and molecular cues that can be used to monitor low-endemic ...
Plasmodium vivax apical membrane antigen-1(PvAMA-1) is a surface protein with polymorphic sites. This study was aimed to analyze the polymorphic amino acid residues at PvAMA-1 in different infected age groups. 92 blood samples were collected from south and southeast of Iran. The DNA coding for the domain I (DI), DII, and partial ...
Plasmodium vivax is a protozoal parasite and a human pathogen. This parasite is the most frequent and widely distributed cause of recurring malaria, P. vivax is one of the five species of malaria parasites that commonly infect humans.[2] Although it is less virulent than Plasmodium falciparum, the deadliest of the five human malaria parasites, P. vivax malaria infections can lead to severe disease and death, often due to splenomegaly .[3][4] P. vivax is carried by the female Anopheles mosquito, since it is only the female of the species that bites.[5]
BACKGROUND: Plasmodium vivax malaria is a major public health challenge in Latin America, Asia and Oceania, with 130-435 million clinical cases per year worldwide. Invasion of host blood cells by P. vivax mainly depends on a type I membrane protein called Duffy binding protein (PvDBP). The erythrocyte-binding motif of PvDBP is a 170 amino-acid stretch located in its cysteine-rich region II (PvDBPII), which is the most variable segment of the protein. METHODS: To test whether diversifying natural selection has shaped the nucleotide diversity of PvDBPII in Brazilian populations, this region was sequenced in 122 isolates from six different geographic areas. A Bayesian method was applied to test for the action of natural selection under a population genetic model that incorporates recombination. The analysis was integrated with a structural model of PvDBPII, and T- and B-cell epitopes were localized on the 3-D structure. RESULTS: The results suggest that: (i) recombination plays an important role in
TY - JOUR. T1 - Genomics, Population Genetics and Evolutionary History of Plasmodium vivax. AU - Carlton, Jane M.. AU - Das, Aparup. AU - Escalante, Ananias A.. PY - 2013. Y1 - 2013. N2 - Plasmodium vivax is part of a highly diverse clade that includes several Plasmodium species found in nonhuman primates from Southeast Asia. The diversity of primate malarias in Asia is staggering; nevertheless, their origin was relatively recent in the evolution of Plasmodium. We discuss how humans acquired the lineage leading to P. vivax from a nonhuman primate determined by the complex geological processes that took place in Southeast Asia during the last few million years. We conclude that widespread population genomic investigations are needed in order to understand the demographic processes involved in the expansion of P. vivax in the human populations. India represents one of the few countries with widespread vivax malaria. Earlier studies have indicated high genetic polymorphism at antigenic loci and no ...
Background: Evidence for decreasing chloroquine (CQ) efficacy against Plasmodium vivax has been reported from many endemic countries in the world. In Ethiopia, P. vivax accounts for 40% of all malaria cases and CQ is the first-line drug for vivax malaria. Mutations in multidrug resistance 1 (pvmdr-1) and K10 insertion in the pvcrt-o genes have been identified as possible molecular markers of CQ-resistance (CQR) in P. vivax. Despite reports of CQ treatment failures, no data are currently available on the prevalence of molecular markers of P. vivax resistance in Ethiopia. The objective of this study was to determine the prevalence of mutations in the pvmdr-1 and K10 insertion in the pvcrt-o genes. Methods: A total of 36 P. vivax clinical isolates were collected from West Arsi district in Ethiopia. Sequencing was used to analyse polymorphisms of the pvcrt-o and pvmdr-1 genes. Results: Sequencing results of the pvmdr-1 fragment showed the presence of two non-synonymous mutations at positions 976 and ...
Participants at this 6th international conference dedicated to Plasmodium vivax malaria research are being treated to the stunning surrounds of the Rio Negro, just upstream of the confluence with the Rio Solimões and the birth of the awesome Amazon river. This exceptional location is no doubt contributing to the buzzing atmosphere as a record 405 colleagues reunite for this conference, enabled in part by an impressive 41 travel awards for students and early-career scientists from across the world.. A busy day of diverse pre-meeting courses overseen by Stefanie Lopes and Carmen Fernandez-Becerra has whet the appetite for the main meeting. Dynamic session organisers (see Programme) triggered lively discussions reminding participants of the key and unique features of P. vivax malaria, and of the challenges and dilemmas confronting the P. vivax community and country programmes in particular.. A morning session led by Rogério Amino, Mary Galinski and Letusa Albrecht covered updates in parasite ...
Background Plasmodium vivax continues to be the most widely distributed malarial parasite species in tropical and sub-tropical areas, causing high morbidity indices around the world. Better understanding of the proteins used by the parasite during the invasion of red blood cells is required to obtain an effective vaccine against this disease. This study describes characterizing the P. vivax asparagine-rich protein (PvARP) and examines its antigenicity in natural infection. Methods The target gene in the study was selected according to a previous in silico analysis using profile hidden Markov models which identified P. vivax proteins that play a possible role in invasion. Transcription of the arp gene in the P. vivax VCG-1 strain was here evaluated by RT-PCR. Specific human antibodies against PvARP were used to confirm protein expression by Western blot as well as its subcellular localization by immunofluorescence. Recognition of recombinant PvARP by sera from P. vivax-infected individuals was ...
We examined geographically distinct isolates of Plasmodium vivax and categorized them according to developmental success in Anopheles albimanus. We found that parasites from Central America and Colombia form a group distinct from those of Asia. New World isolates have a distinct chromosomal translocation and an episomal variation in the open reading frame (ORF) 470 DNA sequence that distinguishes them from the other isolates tested. Old World types of P. vivax were introduced into the Americas, and a remnant of this lineage remains in P. simium. It is indistinguishable from Old World P. vivax to the extent determinable by using our encoded markers and the examination of its developmental pattern in mosquitoes. The cohesive characteristics that separate types of P. vivax are predictors of range and potential for transmission and hence require taxonomic distinction ...
Although Plasmodium vivax is a leading cause of malaria around the world, only a handful of vivax antigens are being studied for vaccine development. Here, we investigated genetic signatures of selection and geospatial genetic diversity of two leading vivax vaccine antigens--Plasmodium vivax merozoite surface protein 1 (pvmsp-1) and Plasmodium vivax circumsporozoite protein (pvcsp). Using scalable next-generation sequencing, we deep-sequenced amplicons of the 42 kDa region of pvmsp-1 (n = 44) and the complete gene of pvcsp (n = 47) from Cambodian isolates. These sequences were then compared with global parasite populations obtained from GenBank. Using a combination of statistical and phylogenetic methods to assess for selection and population structure, we found strong evidence of balancing selection in the 42 kDa region of pvmsp-1, which varied significantly over the length of the gene, consistent with immune-mediated selection. In pvcsp, the highly variable central repeat region also showed patterns
Author summary Plasmodium vivax transmission is heterogeneous and discontinuous in the Peruvian Amazon. Such heterogeneity is the result of factors that include, but are not restricted to, the environment, public policies, and characteristics of the parasite, the vector, and human activities. All these factors make P. vivax transmission resilient to interventions. In order to achieve the goals of control and local elimination, P. vivax surveillance must inform how those factors sustain disease transmission in order to focalize and synchronize control strategies. In this study, we implemented molecular surveillance complemented with population genetic tools in the areas of Cahuide, Lupuna, and Santa Emilia located in the Peruvian Amazon. In particular, we characterize the transmission and the parasite genetic variation in these sites from September 2012 to March 2015. The changes in parasite diversity, the wide geographic dispersion of parasite subpopulation and the introduction of a new parasite clone
Abstract The population dynamics of two Plasmodium vivax polymorphs were studied over a two-year period in a village in a hyperendemic area of Papua New Guinea in both the mosquito and human populations. Strains of P. vivax were distinguished by different circumsporozoite (CS) protein repeats, the VK210 (classic) and the VK247 (variant) polymorphs. In 1986, 34% of P. vivax CS protein-positive mosquitoes were of the VK247 type. Although the proportion of P. vivax sporozoite antigen-positive mosquitoes compared with all sporozoite-positive mosquitoes did not change from 1986 to 1987, the proportion of P. vivax-positive mosquitoes of the VK247 polymorph decreased significantly from 34% to 11% (5 of 45) in 1987. In 1986, 61% (47 of 77) of humans tested had IgGs that recognized the VK247 CS repeat, while only 26% (22 of 84) had IgGs that recognized the VK210 CS repeat. The observed fluctuation in the proportion of the two P. vivax CS protein polymorphs recorded in the mosquito population from 1986 to 1987 is
Authors: Babon, Jeffrey; Morgan, William; Geoff, Kelly; John, Eccleston; James, Feeney; Anthony, Holder. Citation: Babon, Jeffrey; Morgan, William; Kelly, Geoff; Eccleston, John; Feeney, James; Holder, Anthony. Structural studies on Plasmodium vivax merozoite surface protein-1. Mol. Biochem. Parasitol. 153, 31-40 (2007).. Assembly members: ...
BACKGROUND: Despite that over 90 million pregnancies are at risk of Plasmodium vivax infection annually, little is known about the epidemiology and impact of the infection in pregnancy. METHODOLOGY AND PRINCIPAL FINDINGS: We undertook a health facility-based prospective observational study in pregnant women from Guatemala (GT), Colombia (CO), Brazil (BR), India (IN) and Papua New Guinea PNG). Malaria and anemia were determined during pregnancy and fetal outcomes assessed at delivery. A total of 9388 women were enrolled at antennal care (ANC), of whom 53% (4957) were followed until delivery. Prevalence of P. vivax monoinfection in maternal blood at delivery was 0.4% (20/4461) by microscopy [GT 0.1%, CO 0.5%, BR 0.1%, IN 0.2%, PNG 1.2%] and 7% (104/1488) by PCR. P. falciparum monoinfection was found in 0.5% (22/4463) of women by microscopy [GT 0%, CO 0.5%, BR 0%, IN 0%, PNG 2%]. P. vivax infection was observed in 0.4% (14/3725) of placentas examined by microscopy and in 3.7% (19/508) by PCR. P. ...
Project details Renewed intensification of global malaria control efforts over the past 10 years has had significant success, however, key challenges remain, including the predominance of the species Plasmodium vivax in regions nearing elimination. Development of an effective vaccine against P. vivax would make elimination a more attainable goal.
The P. vivax parasite exhibits higher genetic diversity than P. falciparum, especially for the gene families associated with merozoite invasion or immune response modulation (e.g., the msp3, vir, and msp7 gene families) [20-22]. The high genetic diversity and natural selection of P. vivax vaccine targets is common existed in isolates world-wide [23,24]. The PvMSP1 locus codes for a major asexual blood-stage antigen currently proposed as a malaria vaccine candidate antigen. Reports of extensive polymorphism of this protein from field isolates and clones from different geographical areas remain a major challenge. Numerous studies on the genetic diversity of PvMSP1 in P. vivax field isolates have been carried out in many different geographic areas [25,26]. However, there is no available data for PvMSP142 from southern border areas adjacent to Myanmar and the inland cases in China.. In this study, we present several sets of genetic information for PvMSP142 of populations from inland China and CMB ...
Problem/Condition: Malaria in humans is caused by intraerythrocytic protozoa of the genus Plasmodium. These parasites are transmitted by the bite of an infective female Anopheles mosquito. The majority of malaria infections in the United States occu ...
Recurrence rates of Plasmodium vivax infections differ across various geographic regions. Interestingly, South-East Asia and the Asia-Pacific region are documented to exhibit the most frequent recurrence incidences. Identifying patients at a higher risk for recurrences gives valuable information in strengthening the efforts to control P. vivax infections. The aim of the study was to develop a tool to identify P. vivax- infected patients that are at a higher risk of recurrence in Malaysia. Patient data was obtained retrospectively through the Ministry of Health, Malaysia, from 2011 to 2016. Patients with incomplete data were excluded. A total of 2044 clinical P. vivax malaria cases treated with primaquine were included. Data collected were patient, disease, and treatment characteristics. Two-thirds of the cases (n = 1362) were used to develop a clinical risk score, while the remaining third (n = 682) was used for validation. Using multivariate analysis, age (p = 0.03), gametocyte sexual count (p = 0.04),
Association between malaria and risk factors. Frequencies for risk factors among cases and controls and associated bivariate and multivariate odds ratios are presented in table III. Eighteen variables out of 99 were significantly associated (p , 0.05) with increased risk of malaria. Correlation coefficient values were less than 0.8 in all cases, indicating no colinearity. The percentages of cases and controls that referred to a place of birth other than the locality where they were living were 23.5 and 13.45%, respectively, and this condition was associated with a three-fold (OR 3.16, 95% CI 1.16-6.13) greater risk of malaria infection.. The risk of malaria infection increased in subjects who spoke only an autochthonous language (13.4%, OR 2.48, 95% CI 1.19-3.77) compared to subjects who spoke Spanish and both Spanish and an autochthonous language (4.2%).. The proportions of cases in the medium and low MKI levels were 48.7% and 31.0%, respectively, compared to 48.3 and 24.4 % of controls, ...
GSK and Medicines for Malaria Venture announced FDA approval of single-dose tafenoquine for the radical cure (prevention of relapse) of Plasmodium vivax malaria in patients aged 16 years and older who are receiving appropriate antimalarial therapy for acute P. vivax infection.. Tafenoquine is an 8-aminoquinoline derivative with activity against all stages of the P. vivax life cycle, including hypnozoites. It was first synthesised by scientists at the Walter Reed Army Institute of Research in 1978. Approval was based on efficacy and safety data from a comprehensive global clinical development P. vivax radical cure program designed in agreement with FDA. Thirteen studies in healthy volunteers and patients directly supported the program.. The primary evidence for clinical efficacy and safety of the 300-mg single dose was provided by three randomized, double-blind studies: DETECTIVE Part 1 and Part 2 (TAF112582) and GATHER (TAF116564) involving 800 participants. Results of the two Phase III studies ...
Analysis of lymphocytes in patients with Plasmodium vivax malaria and its relation to the annexin-A1 and IL-10: BackgroundMalaria is the most prevalent parasiti
The malaria burden in Viet Nam has been in decline in recent decades, but localised areas of high transmission remain. We used spatiotemporal analytical tools to determine the social and environmental drivers of malaria risk and to identify residual high-risk areas where control and surveillance resources can be targeted. Counts of reported Plasmodium falciparum and Plasmodium vivax malaria cases by month (January 2007-December 2008) and by district were assembled. Zero-inflated Poisson regression models were developed in a Bayesian framework. Models had the percentage of the districts population living below the poverty line, percent of the district covered by forest, median elevation, median long-term average precipitation, and minimum temperature included as fixed effects, and terms for temporal trend and residual district-level spatial autocorrelation. Strong temporal and spatial heterogeneity in counts of malaria cases was apparent. Poverty and forest cover were significantly associated with an
|strong|Human anti plasmodium vivax LDH, clone AbD13978|/strong| recognizes LDH (L-lactose dehydrogenase) from the Malaria causing protozoan species |i|Plasmodium vivax|/i|. It was shown to cross-reac…
In 2002, the vivax malaria community has created a forum for providing a friendly environment to share and discuss research results on Plasmodium vivax. Meetings were held in Bangkok, Rockville, Panama, Barcelona, Bali, and, this year, in Manaus.. The aim of this Thematic series Time to go for vivax (the motto of the Manaus meeting) is to emphasize this biennial event and the role it plays in the promotion of work on Plasmodium vivax. The articles in the series are all based on presentations given in Manaus.. Guest editors: Marcus V Lacerda and Hernando A del Portillo.. ...
Background: Cytokine-mediated endothelial activation pathway is a known mechanism of pathogenesis employed by Plasmodium falciparum to induce severe disease symptoms in human host. Though considered benign, complicated cases of Plasmodium vivax are being reported worldwide and from Pakistan. It has been hypothesized that P.vivax utilizes similar mechanism of pathogenesis, as that of P.falciparum for manifestations of severe malaria. Therefore, the main objective of this study was to characterize the role of cytokines and endothelial activation markers in complicated Plasmodium vivax isolates from Pakistan. Methods and Principle Findings: A case control study using plasma samples from well-characterized groups suffering from P.vivax infection including uncomplicated cases (n=100), complicated cases (n=82) and healthy controls (n=100) were investigated. Base line levels of Tumor necrosis factor-α (TNF-α), Interleukin-6 (IL-6), Interleukin-10 (IL-10), Intercellular adhesion molecule-1 (ICAM-1), Vascular
Travelers to many parts of the world are at risk for contracting malaria, According to the Centers for Disease Control and Prevention (CDC), approximately 1,700 cases occur each year among international travelers from the United States.. The US Food and Drug Administration (FDA) has recently approved the drug tafenoquine for two indications: Prophylaxis of malaria ( It can be used as prophylaxis in patients ≥18 years of age against all Plasmodium spp. and in any malarious area) and radical cure of Plasmodium vivax malaria.. Choosing a Drug to Prevent Malaria. The long half-life of tafenoquine (approximately 16 days) offers potential advantages in less frequent dosing for prophylaxis and a single-dose course for treatment.. ...
The research, carried out on the border of Thailand and Myanmar, highlights the importance of preventing malaria in pregnancy.. According to the World Malaria Report 2011, malaria killed an estimated 655 000 people in 2010. It is caused by parasites such as Plasmodium falciparum and Plasmodium vivax, which are injected into the bloodstream by infected mosquitoes.. Malaria is one of the most common parasitic infections to affect pregnancy. Previous studies have suggested that infection with both P. falciparum and P. vivax malaria during pregnancy reduces birth weight whether maternal symptoms are present or not; however, these studies have been hampered by difficulties in estimating gestational age accurately and diagnosing malaria infection in early pregnancy.. Now, in a study published in the open access journal PLoS One, researchers at the Shoklo Malaria Research Unit on the border of Thailand and Myanmar, part of the Wellcome Trust-Mahidol University-Oxford University Tropical Medicine ...
P. vivax along with other parasites within the Plasmodium genus rely on both an insect and vertebrate host to act as vectors for their infection. Additionally P. vivax uses the proteins within the blood of humans to reproduce and produce their own proteins. Once within the blood new mosquitoes that have not been infected and are hosts to the parasite can feed on the vertebrate host and themselves become an insect host to P vivax and further spread the infection to other vertebrae. This leads to the easy passive dispersal of the parasite. This parasitic nature leaves the host in potentially life-threatening danger, for up to years at a time. ...
The complex imprinted GNAS locus which encodes G-alpha subunit (G�s) is involved in a number of Gprotein coupled signaling pathways in eukaryotic cells. Erythrocyte invasion by Plasmodium falciparum parasites is significantly regulated by protein of GNAS gene. This study was designed to evaluate the association between single nucleotide polymorphisms (SNPs) present in GNAS locus and susceptibility to malaria. In this case control study, individuals affected by P. falciparum malaria (n = 230), Plasmodium vivax malaria (n = 230) and normal controls (n = 230) were tested for the association of eighteen (18) known SNPs to evaluate their role in the onset of the disease. There was no significant difference in genotype frequencies of all the SNPs tested between P. falciparum and P. vivax affected individuals. However, when Bonferroni correction for multiple comparisons were performed as a control, our results demonstrated alleles and genotypes of rs7121: C , T (NC 000020.10:g.57478807C , T), a ...
A large clinical trial led by Dr. Ivo Mueller, researcher at ISGlobal and the Walter and Eliza Hall Institute, Australia, shows that a great majority of P. vivax infections among children in Papua New Guinea are caused by the reactivation of hypnozoites, a dormant liver-stage of the parasite, and that these relapses contribute importantly to sustaining disease transmission. Further results of the study, published in Plos Medicine, indicate that massive drug administration campaigns combining blood- and liver- stage treatments are highly efficient for reducing P. vivax transmission and thereby provide important evidence-based recommendations for policy makers.. Over the last 20 years, there has been a significant reduction in overall malaria incidence. In parallel, outside Africa there has been a shift in Plasmodium species, with P. vivax now accounting for more than 90% of clinical cases in the vast majority of countries. P. vivax has the ability to relapse weeks, months or years after primary ...
The study is a proof-of-concept clinical investigation designed to develop a safe and practical sporozoite challenge model for Plasmodium vivax in humans with a goal of 100% infectivity rate. The development and standardization of such a model will make possible efficacy evaluations of candidate P. vivax vaccines in Phase 2a trials. This trial is conducted in collaboration with Armed Forces Research Institute of Medical Sciences (AFRIMS) investigators in Bangkok, Thailand, who will be recruiting adult blood donors from a pool of patients who present with active P. vivax infections in Thailand. Samples of P. vivax infected blood will be collected and fed via membrane feeding apparatus to colony-reared Anopheles dirus mosquitoes at the AFRIMS Entomology Lab. A portion of the same blood will meanwhile be screened for potential co-infections at the AFRIMS Retrovirology Laboratory. When screening tests have confirmed the presence of only P. vivax in the blood (no co-infections with other malaria ...
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Abstract: BACKGROUND: Malaria is of immense importance amongst the tropical diseases in India. There is a need to develop newer diagnostic aids and research is necessary to identify new prognostic markers for prediction of the course and complications. AIMS: To evaluate the white cell differential count and morphology in Plasmodium vivax and Plasmodium falciparum malaria and study their prognostic utility. SUBJECTS AND METHODS: Two hundred and sixty-four adult patients in the age range of 20 to 65 years presenting to the hospital over a period of 4 months with clinical features of malaria and a positive peripheral smear examination were studied. RESULTS: No statistically significant difference was noted in the white blood cell (WBC) count and neutrophil count in P.vivax versus P. falciparum malaria. Band cells were more frequently noted in P. falciparum malaria than in P.vivax malaria (p < 0.0001). Toxic granulation of the neutrophils was noted in 9.5% of the patients and exclusively in P. ...
RNP, LvS, JKB, NJW, JAS and NPD designed the study and all authors assisted in revision of the final protocol ethical submissions, YL designed the economic component of the study and AD assisted. TA, BA, AA, AGR, BB, SG, TTH, DJ, MK, AK, TL, IM, ZM, APP, NHP, HS, IS, YT, NVT, AW, RZ provide the logistics of setting up the study sites. PYC, MD, AMD, NHK, BL, PY and KT provide clinical trial support. KT and RNP wrote the first draft of the manuscript and all authors reviewed and contributed to the manuscript. The members of the IMPROV study group are (in alphabetical order): Tesfay Abreha, ICAP at Columbia Universitys Mailman School of Public Health, Addis Ababa, Ethiopia ([email protected]); Bereket Alemayehu, ICAP at Columbia Universitys Mailman School of Public Health, New York, USA ([email protected]); Ashenafi Assefa, Ethiopian Public Health Institute, Addis Ababa, Ethiopia ([email protected]); Ghulam Rahim Awab, Nangarhar Medical Faculty of Nangarhar University, Afghanistan ...
A new blood-stage parasite question has arisen. Are erythrocytic forms in bone marrow/spleen part of the hidden Plasmodium vivax reservoir? Do they cause or contribute to renewed or increased peripheral parasitaemia? (Link to the article on the subject [click here]).. ...
The association between SAO and P. vivax infection was examined through genotyping of 1,975 children enrolled in three independent epidemiological studies conducted in the Madang area of Papua New Guinea. SAO was associated with a statistically significant 46% reduction in the incidence of clinical P. vivax episodes (adjusted incidence rate ratio [IRR] = 0.54, 95% CI 0.40-0.72, p,0.0001) in a cohort of infants aged 3-21 months and a significant 52% reduction in P. vivax (blood-stage) reinfection diagnosed by PCR (95% CI 22-71, p = 0.003) and 55% by light microscopy (95% CI 13-77, p = 0.014), respectively, in a cohort of children aged 5-14 years. SAO was also associated with a reduction in risk of P. vivax parasitaemia in children 3-21 months (1,111/µl versus 636/µl, p = 0.011) and prevalence of P. vivax infections in children 15-21 months (odds ratio [OR] = 0.39, 95% CI 0.23-0.67, p = 0.001). In a case-control study of children aged 0.5-10 years, no child with SAO was found among 27 cases with ...