| malaria at humaita county, amazonas state, brazil. some aspects. | | 1982 | 6764289 |
| plasmodium vivax resistance to chloroquine (r2) and mefloquine (r3) in brazilian amazon region. | we report for the first time a patient with malaria due to plasmodium vivax who showed r2 resistance to chloroquine and r3 resistance to mefloquine in the brazilian amazon region based on who clinical criteria for diagnosis of malaria resistance. failure was observed with unsupervised oral chloroquine, chloroquine under rigorous supervision and mefloquine in the same scheme. finally, the patient was cured with oral artesunate. | 1999 | 9927829 |
| prevalence of plasmodium vivax variants vk247 and p. vivax-like human malaria: a retrospective study in indigenous indian populations of the amazon region of brazil. | | 1998 | 10326105 |
| description of a possible clonal expansion of plasmodium vivax in manaus-amazonas-brazil. | atypical p. vivax cases reported in manaus municipality led us to detect a genetic isolate of p. vivax. variable regions of ssurrna were examined from the initial time of infection and in the two recrudescences/relapses from a patient exhibiting chloroquine and primaquine resistance. a unique isolate, found at all stages of infection, suggests the presence of a clonal expansion. | 1999 | 10380572 |
| in-vivo sensitivity of plasmodium vivax isolates from rond nia (western amazon region, brazil) to regimens including chloroquine and primaquine. | seventy-nine adults with plasmodium vivax malaria, from the porto velho area of rond nia (western amazon region, brazil), gave informed consent to participate in a blind, clinical study of two regimens of treatment with chloroquine (cq) and primaquine. the effectiveness of the 'classical' regimen (cq for 3 days, followed by primaquine for 14 days) was compared with that of a 'short' regimen in which the two drugs were given simultaneously for 5 days. there were no cases of recrudescence indicati ... | 2000 | 11214093 |
| correlation between plasmodium vivax variants in belém, pará state, brazil and symptoms and clearance of parasitaemia. | the aim of this study was to determine how different types of p. vivax affect clinical symptoms and parasitaemia clearance. blood was collected from individuals from pará state, brazil. the patients were treated as chloroquine plus primaquine. p. vivax were typed daily till d7 and again on d30. now we can confirm a previously reported correlation between p. vivax genotype and response to chloroquine. clinical symptoms do not allow for objective identification of different p. vivax types in the b ... | 2003 | 14499040 |
| the genetic diversity of plasmodium vivax--a review. | the genetic diversity of plasmodium vivax has been investigated in several malaria-endemic areas, including the brazilian amazon region, where this is currently the most prevalent species causing malaria in humans. this review summarizes current views on the use of molecular markers to examine p. vivax populations, with a focus on studies performed in brazilian research laboratories. we emphasize the importance of phylogenetic studies on this parasite and discuss the perspectives created by our ... | 2007 | 17568928 |
| plasmodium vivax infection among duffy antigen-negative individuals from the brazilian amazon region: an exception? | we present evidence for plasmodium vivax infection among duffy blood group-negative inhabitants of brazil. the p. vivax identification was determined by both genotypic and non-genotypic screening tests. the duffy blood group was genotyped by pcr/rflp and phenotyped using a microtyping kit. we detected two homozygous fy*b-33 carriers infected by p. vivax, whose circumsporozoite protein genotypes were vk210 and/or p. vivax-like. additional efforts are necessary in order to clarify the evidence tha ... | 2007 | 17604067 |
| [evaluation of the optimal-it and ict p.f./p.v. rapid dipstick tests for diagnosing malaria within primary healthcare in the municipality of manaus, amazonas]. | malaria is routinely diagnosed using the thick blood smear test. however, this technique requires the training of microscopists and may be time-consuming. a concordance study was conducted on two dipstick tests (optimal-it and ict p.f./p.v.) and the thick blood smear test, within primary healthcare in manaus. | 2007 | 17486264 |
| molecular epidemiology of plasmodium vivax in the state of amazonas, brazil. | over the past 2 decades, the amazon region of brazil has experienced reemergence of plasmodium vivax malaria, with reported occurrence of severe disease. the frequency and manifestations of this severe disease are unlike previous clinical experience. the hypothesis has been raised that the occurrence of severe disease may relate to the emergence of a variant form of the parasite. to test this hypothesis, we conducted a retrospective cohort study of p. vivax strains in the state of amazonas. we d ... | 2007 | 17397788 |
| molecular screening of plasmodium sp. asymptomatic carriers among transfusion centers from brazilian amazon region. | the transmission of malaria in brazil is heterogeneous throughout endemic areas and the presence of asymptomatic plasmodium sp. carriers (apcs) in the brazilian amazon has already been demonstrated. malaria screening in blood banks is based on the selection of donors in respect to possible risks associated with travel or residence, clinical evidence and/or inaccurate diagnostic methods thereby increasing the probability of transfusion-transmitted infection. we evaluated the frequency of apcs in ... | 2007 | 17384812 |
| [coinfection between hepatitis b virus and malaria: clinical, serologic and immunologic aspects]. | the amazon region is known for a high prevalence of hepatitis b infection, and accounts for more than 90% of malaria cases in brazil. it has been suggested that the occurrence of coinfections may be important, and may influence the natural history of both diseases. this study evaluated 545 patients with acute malaria, in coari, western brazilian amazon. 333 (61.1%) presented plasmodium vivax malaria, 193 (35.4%) plasmodium falciparum and 19 (3.5%) mixed infections. the hbsag prevalence was 4.2% ... | 2006 | 16501762 |
| the pattern of major polymorphisms in the duffy binding protein ligand domain among plasmodium vivax isolates from the brazilian amazon area. | | 2006 | 16384615 |
| asymptomatic carriers of plasmodium spp. as infection source for malaria vector mosquitoes in the brazilian amazon. | we have described the existence of asymptomatic carriers of plasmodium vivax and plasmodium falciparum infections in native amazon populations. most of them had low parasitemias, detected only by polymerase chain reaction (pcr). because they remain symptomless and untreated, we wanted to determine whether they could infect anopheles darlingi root, the main brazilian vector, and act as disease reservoirs. fifteen adult asymptomatic patients (pcr positive only) were selected, and experimental infe ... | 2005 | 16363160 |
| malaria diagnosis and hospitalization trends, brazil. | we focused on rates of malaria in the state of amazonas and city of manaus, brazil. plasmodium vivax accounted for an increased number and rate of hospital admissions, while p. falciparum cases decreased. our observations on malaria epidemiology suggest that the increased hospitalization rate could be due to increased severity of p. vivax infections. | 2007 | 18258018 |
| [plasmodium vivax malaria in the brazilian amazon: some aspects of its epidemiology, clinical spectrum and naturally induced immune responses]. | malaria was a nationwide problem in brazil in the 1940's. however during the late fifties a national and successful campaign gained strength in the country decreasing malaria to its lowest level by 1960, when only 36,9 thousand cases were registered. although the malaria eradication program of the ministry of health in brazil succeeded by the late 60's in freeing the majority of the country from malaria transmission, it was unable to contain the rapid spread of the disease in the amazon basin. i ... | 2008 | 18683322 |
| anti-plasmodium vivax duffy binding protein antibodies measure exposure to malaria in the brazilian amazon. | plasmodium vivax duffy binding protein (dbp) is functionally important in the erythrocyte invasion process and provides a logical target for vaccine-mediated immunity. in the current study, we demonstrated that dbp is naturally immunogenic in different populations of the brazilian amazon, and the proportions of dbp igg positive subjects increased with exposure to malaria, reaching a peak in those subjects with long-term exposure (> 15 years) in the amazon area. this profile of antibody response ... | 2005 | 15964949 |
| [seroprevalence of hepatitis b and malaria infection in lábrea, brazilian western amazon: estimates of coinfection rates]. | the amazon region is known for the high occurrence of hepatitis b virus (hbv) infection, and accounts for more than 98% of malaria cases in brazil. despite the controversy, it has been proposed that when associated they may lead to important effects in the natural history of both infections. this study estimates the prevalence of coinfection within general population of an endemic region of hbv and malaria in the brazilian amazon. the prevalence of hbsag was 3.3% (95% ci 2.1%-5.1%,) and total an ... | 2005 | 15895171 |
| cross-sectional study defines difference in malaria morbidity in two yanomami communities on amazonian boundary between brazil and venezuela. | it is well established that immunity to malaria is short-lived and is maintained by the continuous contact with the parasite. we now show that the stable transmission of malaria in yanomami amerindian communities maintains a degree of immunity in the exposed population capable to reduce prevalence and morbidity of malaria. we examined 508 yanomami amerindians living along orinoco (407) and mucajaí (101) rivers, on the venezuelan and brazilian amazon region, respectively. at orinoco villages, mal ... | 2004 | 15322625 |
| idiopathic thrombocytopenic purpura due to vivax malaria in the brazilian amazon. | we describe a rare case of idiopathic thrombocytopenic purpura (itp) triggered by plasmodium vivax infection. the patient developed thrombocytopenia and bleeding associated with three episodes of malaria, and became dependent on corticosteroid therapy. the mechanisms by which this parasite evokes thrombocytopenia remain obscure. | 2004 | 15177145 |
| assessment of chloroquine single dose treatment of malaria due to plasmodium vivax in brazilian amazon. | malaria regions of the amazon basin have been characterized by difficult access and non-compliance of the patients to treatment. in an attempt to assess the schizonticide efficacy of chloroquine in a single dose of 600 mg, the authors realized a double-blind, placebo-controlled trial in 132 outpatients with vivax malaria. patients were distributed into two groups: group cpla, given chloroquine 600 mg (single dose) on the first day of treatment, and two doses of placebo on second and third days. ... | 2004 | 14762633 |
| duffy blood group genotypes among malaria patients in rondônia, western brazilian amazon. | we have compared duffy blood group genotype distribution, as determined by polymerase chain reaction with allele-specific primers, in 68 plasmodium vivax-infected patients and 59 non-vivax malaria controls from rondônia, brazil. homozygosity for the allele fy, which abolishes duffy antigen expression on erythrocytes, was observed in 12% non-vivax controls but in no p. vivax patient. however, no significant association was found between fy heterozygosity and protection against p. vivax. the fy x ... | 2001 | 11813069 |
| distribution of plasmodium vivax variants (vk210, vk247 and p. vivax-like) in three endemic areas of the amazon region of brazil and their correlation with chloroquine treatment. | the present study evaluated the glass fibre membrane (gfm)-polymerase chain reaction (pcr)-enzyme-linked immunosorbent assay (elisa) technique for genotyping the plasmodium vivax variants, to verify the distribution of p. vivax variants (vk210, vk247 and p. vivax-like) in parts of brazil and their correlation with levels of parasitaemia, previous malaria experience and clearance of parasitaemia linked to different treatment schedules. the samples were taken from individuals living in macapá, por ... | 2000 | 11127238 |
| development of a polymerase chain reaction (pcr) method based on amplification of mitochondrial dna to detect plasmodium falciparum and plasmodium vivax. | in this study we standardized a new technical approach in which the target mitochondrial dna sequence (mtdna) is amplified using a simple but sensitive pcr method as a tool to detect plasmodium falciparum and plasmodium vivax. specific primers were designed to hybridize with cytochrome c oxidase genes of p. falciparum (cox iii) and p. vivax (cox i). amplification products were obtained for all positive samples, presenting homology only for species-specific mtdna. sensitivity and specificity were ... | 2009 | 19426660 |
| antibody response against plasmodium falciparum exoantigens and somatic antigens: a longitudinal survey in a rural community in rondônia, western brazilian amazon. | three clinical and sero-epidemiological cross-sectional surveys involving 50 subjects were performed at six-month intervals in urupá, a rural community characterized by unstable malaria transmission, situated in rondônia state, western brazilian amazon. between the surveys, a clinically and parasitologically passive surveillance was established in this community and 48 malaria attacks (28 due to plasmodium falciparum and 20 due to plasmodium vivax) were recorded in this cohort of 50 subjects. se ... | 1994 | 7942353 |
| anti-anopheles darlingi saliva antibodies as marker of plasmodium vivax infection and clinical immunity in the brazilian amazon. | despite governmental and private efforts on providing malaria control, this disease continues to be a major health threat. thus, innovative strategies are needed to reduce disease burden. the malaria vectors, through the injection of saliva into the host skin, play important role on disease transmission and may influence malaria morbidity. this study describes the humoral immune response against anopheles (an.) darlingi saliva in volunteers from the brazilian amazon and addresses the association ... | 2009 | 19500362 |
| malaria is associated with poor school performance in an endemic area of the brazilian amazon. | approximately 40% of the world's population is at risk for malaria. in highly endemic tropical areas, malaria is a major cause of morbidity and mortality during infancy. there is a complex interrelationship between malaria, malnutrition and intestinal helminths, and this may impair cognitive development in children. the aim of this study was to determine the relationship between malaria and school performance in children living in an endemic area where plasmodium vivax is the species responsible ... | 2009 | 19835584 |
| malaria vectors in two indigenous reserves of the brazilian amazon. | to describe the composition, ecological and behavioral characteristics and infectivity of anopheles species in indigenous reserves of the amazon region. | 2009 | 19851633 |
| the malarial impact on the nutritional status of amazonian adult subjects. | the anthropometric (body weight, height, upper arm circumference, triceps and subescapular skinfolds; quetelet index and arm muscle circumference) and blood biochemistry (proteins and lipids) parameters were evaluated in 93 males and 27 females, 17-72 years old voluntaries living in the malarial endemic area of humaita city (southwest amazon). according to their malarial history they were assembled in four different groups: g1--controls without malarial history (n:30); g2--controls with malarial ... | 1995 | 7569636 |
| [malaria in the municipality of humaitá, state of amazonas. xi - parasitological aspects]. | | 1981 | 7046016 |
| [malaria in the municipality of humaitá, state of amazonas. ix - incidence of blood group systems in inhabitants of the region and in patients]. | | 1981 | 7046015 |
| [malaria in the municipality of humaitá, state of amazonas. iii - clinical and developmental aspects]. | | 1981 | 7046012 |
| infrequency of asymptomatic malaria in an endemic area in amazonas, brazil. | | 1988 | 3074390 |
| effects of immigration on the prevalence of malaria in rural areas of the amazon basin of brazil. | epidemiological studies were conducted on malaria in three rural areas of the amazon basin in the state of rondônia: the town of costa marques, forte principe da beira (fort), and an immigrant settlement in the nearby forest. these studies were instituted to document the malaria problem and to describe the role of immigration on its distribution and prevalence. hospital records in the town show that the number of malaria cases increased five fold from 1983 to 1987 and that the predominant malari ... | 1989 | 2487445 |
| human igg responses against the n-terminal region of the merozoite surface protein 1 of plasmodium vivax. | the complete primary structure of the gene encoding the merozoite surface protein 1 of plasmodium vivax (pvmsp-1) revealed the existence of interspecies conserved regions among the analogous proteins of other plasmodia species. here, three dna recombinant clones expressing 50, 200 and 500 amino acids from the n-terminal region of the pvmsp-1 protein were used on elisa and protein immunoblotting assays to look at the igg antibody responses of malaria patients from the brazilian amazon region of r ... | 1992 | 1343729 |
| cross sectional study reveals a high percentage of asymptomatic plasmodium vivax infection in the amazon rio negro area, brazil. | a parasitological, clinical, serological and molecular cross-sectional study carried out in a highly endemic malaria area of rio negro in the amazon state, brazil, revealed a high prevalence of asymptomatic plasmodium vivax infection. a total of 109 persons from 25 families were studied in five villages. ninety-nine inhabitants (90.8%) had at least one previous episode of malaria. serology showed 85.7% and 46.9% of positivity when p. falciparum antigens and p. vivax msp-1, respectively, were use ... | 2007 | 17625693 |
| prevalence and level of antibodies to the circumsporozoite protein of human malaria parasites in five states of the amazon region of brazil. | the aim of this study was to determine the prevalence of malaria infection and antibodies against the repetitive epitopes of the circumsporozoite (cs) proteins of plasmodium falciparum, p. malariae, p. vivax vk210, p. vivax vk247, and p. vivax-like in individuals living in the states of rondônia, pará, mato grosso, amazonas, and acre. active malaria transmission was occurring in all studied sites, except in acre. p. falciparum was the predominant species in pará and rondônia and p. vivax in mato ... | 2007 | 17568943 |
| duffy blood group gene polymorphisms among malaria vivax patients in four areas of the brazilian amazon region. | duffy blood group polymorphisms are important in areas where plasmodium vivax predominates, because this molecule acts as a receptor for this protozoan. in the present study, duffy blood group genotyping in p. vivax malaria patients from four different brazilian endemic areas is reported, exploring significant associations between blood group variants and susceptibility or resistance to malaria. | 2007 | 18093292 |
| naturally acquired antibodies to merozoite surface protein (msp)-1(19) and cumulative exposure to plasmodium falciparum and plasmodium vivax in remote populations of the amazon basin of brazil. | to infer recent patterns of malaria transmission, we measured naturally acquired igg antibodies to the conserved 19-kda c-terminal region of the merozoite surface protein (msp)-1 of both plasmodium vivax (pvmsp-1(19)) and plasmodium falciparum (pfmsp-1(19)) in remote malaria-exposed populations of the amazon basin. community-based cross-sectional surveys were carried out between 2002 and 2003 in subjects of all age groups living along the margins of the unini and jaú rivers, northwestern brazil. ... | 2007 | 18209933 |
| chloroquine-resistant plasmodium vivax, brazilian amazon. | | 2007 | 18214203 |
| inhibitory properties of the antibody response to plasmodium vivax duffy binding protein in an area with unstable malaria transmission. | the function of the plasmodium vivax duffy binding protein (dbp) during the erythrocyte invasion process is critical for successful parasite growth and pathogenesis in human infections. although dbp is the subject of intensive malaria vaccine research, investigations on the functional proprieties of anti-dbp antibodies in the human population have been limited [infect immun68 (2000) 3164]. in the present study, we examined the ability of sera from different populations of the brazilian amazon--a ... | 2008 | 18226014 |
| similar cytokine responses and degrees of anemia in patients with plasmodium falciparum and plasmodium vivax infections in the brazilian amazon region. | the mechanisms of malarial anemia induction are poorly understood, but cytokines and autoantibodies are considered to play important roles. this work aimed at evaluating the degree of anemia and the plasmatic profile of the cytokines tumor necrosis factor alpha (tnf-alpha), gamma interferon (ifn-gamma), interleukin-12 (il-12), migration inhibitory factor (mif), and il-10 and the monocyte chemotactic protein-1 (mcp-1) chemokine, as well as evaluating the presence of antibodies directed to compone ... | 2008 | 18256207 |
| plasmodium vivax circumsporozoite variants and duffy blood group genotypes in the brazilian amazon region. | the circumsporozoite protein (csp) of the plasmodium vivax infective sporozoite is considered to be a major target for the development of recombinant malaria vaccines. the duffy blood group molecule acts as the red blood cell receptor for p. vivax. we review the frequency of p. vivax csp variants and report their association with the duffy blood group genotypes from brazilian amazon patients carrying p. vivax malaria. peripheral blood samples were collected from 155 p. vivax-infected individuals ... | 2009 | 18804827 |
| comparison of igg reactivities to plasmodium vivax merozoite invasion antigens in a brazilian amazon population. | naturally acquired antibody reactivity to two major plasmodium vivax vaccine candidates was investigated in 294 donors from three malaria-endemic communities of rondônia state, brazil. antibody recognition of recombinantly expressed antigens covering five different regions of p. vivax reticulocyte binding protein 1 (pvrbp1) and region ii of p. vivax duffy binding protein (pvdbp-rii) were compared. positive igg responses to these antigens were significantly related to the level of malaria exposur ... | 2005 | 16103583 |
| [molecular diagnosing of malaria in a tertiary care center in the brazilian amazon region]. | the routine test for diagnosing malaria is still the thick blood smear, despite its known decreased sensitivity and specificity in situations of low parasite density and mixed infections. the polymerase chain reaction is increasingly being used for molecular detection and identification of plasmodium species, due to its higher sensitivity and specificity. nested pcr was performed on whole-blood samples from 344 patients with acute febrile syndrome who came to a tertiary healthcare center in mana ... | 2008 | 18853011 |
| genetic polymorphisms in tlr4, cr1 and duffy genes are not associated with malaria resistance in patients from baixo amazonas region, brazil. | the main purpose of this research was to analyze the relation of the genetic polymorphisms frequently expressed by antigen-presenting cells, erythrocytes and malaria susceptibility/resistance with the human malaria infection cases. the sample used consisted of 23 plasmodium vivax (pv)- and p. falciparum (pf)-infected patients, and 21 healthy individuals as a control group, from the baixo amazonas population in pará, brazil. the asp299gly polymorphisms in the toll-like receptor 4 (tlr4), and gly4 ... | 2008 | 19048480 |
| comparative hematologic analysis of uncomplicated malaria in uniquely different regions of unstable transmission in brazil and colombia. | information on malaria-associated anemia in adult patients is scarce in south american populations. from 2004 to 2006, malaria patients 18 to 45 years of age were recruited in a descriptive cross-sectional study from two different towns: manaus, in the brazilian amazon (120 patients) where plasmodium falciparum incidence is lower ( approximately 20%), and in tumaco on the colombian pacific coast (126 patients) where p. falciparum incidence is higher ( approximately 90%). relationships between he ... | 2009 | 19141853 |
| hla class ii and antibody responses to circumsporozoite protein repeats of p. vivax (vk210, vk247 and p. vivax-like) in individuals naturally exposed to malaria. | we studied the seroreactivity against the circumsporozoite protein (csp) repeats of plasmodium vivax variants in individuals living in malaria-endemic area of the brazilian amazon region (candeias do jamari - ro). the prevalence of igg antibodies for at least one of the p. vivax csp repeats was 49%. among these positive individuals, 34.2% were positive for the standard repeat sequence vk210, 24% for the vk247 and 31.5% for the p. vivax-like sequence. hla typing showed an association between anti ... | 2004 | 15301976 |
| age-dependent acquisition of protective immunity to malaria in riverine populations of the amazon basin of brazil. | five community-based cross-sectional surveys of malaria morbidity and associated risk factors in remote riverine populations in northwestern brazil showed average parasite rates of 4.2% (thick-smear microscopy) and 14.4% (polymerase chain reaction [pcr]) in the overall population, with a spleen rate of 13.9% among children 2-9 years of age. plasmodium vivax was 2.8 times more prevalent than p. falciparum, with rare instances of p. malariae and mixed-species infections confirmed by pcr; 9.6% of a ... | 2009 | 19270298 |
| glucose-6-phosphate dehydrogenase deficiency in an endemic area for malaria in manaus: a cross-sectional survey in the brazilian amazon. | there is a paucity of information regarding glucose-6-phosphate dehydrogenase (g6pd) deficiency in endemic areas for malaria in latin america. | 2009 | 19370159 |
| analysis of genetic variability of plasmodium vivax isolates from different brazilian amazon areas using tandem repeats. | few genetic markers have been described to analyze populations of plasmodium vivax. the genetic variability of p. vivax has been analyzed mainly among isolates taken from areas ranging from hyper- to holoendemic areas. these studies of genetic variability have neglected many areas with different epidemiologic profiles. the purpose of this study was to analyze the genetic variability of p. vivax isolates from four different brazilian amazon areas. we chose to study the five most polymorphic tande ... | 2009 | 19407114 |
| malaria in brazil: what happens outside the amazonian endemic region. | brazil, a country of continental proportions, presents three profiles of malaria transmission. the first and most important numerically, occurs inside the amazon. the amazon accounts for approximately 60% of the nation's territory and approximately 13% of the brazilian population. this region hosts 99.5% of the nation's malaria cases, which are predominantly caused by plasmodium vivax (i.e., 82% of cases in 2013). the second involves imported malaria, which corresponds to malaria cases acquired ... | 0 | 25185003 |
| analysis of single-nucleotide polymorphisms in the crt-o and mdr1 genes of plasmodium vivax among chloroquine-resistant isolates from the brazilian amazon region. | plasmodium vivax parasites with chloroquine resistance (cqr) are already circulating in the brazilian amazon. complete single-nucleotide polymorphism (snp) analyses of coding and noncoding sequences of the pvmdr1 and pvcrt-o genes revealed no associations with cqr, even if some mutations had not been randomly selected. in addition, striking differences in the topologies and numbers of snps in these transporter genes between p. vivax and p. falciparum reinforce the idea that mechanisms other than ... | 2009 | 19451296 |
| detection of plasmodium falciparum and plasmodium vivax subclinical infection in non-endemic region: implications for blood transfusion and malaria epidemiology. | in brazil, malaria is endemic in the amazon river basin and non-endemic in the extra-amazon region, which includes areas of são paulo state. in this state, a number of autochthonous cases of malaria occur annually, and the prevalence of subclinical infection is unknown. asymptomatic infections may remain undetected, maintaining transmission of the pathogen, including by blood transfusion. in these report it has been described subclinical plasmodium infection in blood donors from a blood transfus ... | 2014 | 24906577 |
| naturally acquired antibodies to plasmodium vivax duffy binding protein (dbp) in brazilian amazon. | duffy binding protein (dbp), a leading malaria vaccine candidate, plays a critical role in plasmodium vivax erythrocyte invasion. sixty-eight of 366 (18.6%) subjects had igg anti-dbp antibodies by enzyme-linked immunosorbent assay (elisa) in a community-based cross-sectional survey in the brazilian amazon basin. despite continuous exposure to low-level malaria transmission, the overall seroprevalence decreased to 9.0% when the population was reexamined 12 months later. antibodies from 16 of 50 ( ... | 2010 | 20133990 |
| fy polymorphisms and vivax malaria in inhabitants of amazonas state, brazil. | although the importance of glycoprotein duffy in the human red cells invasion process by plasmodium vivax merozoites has been demonstrated, little is known about the associations of fy polymorphisms with malaria vivax parasitic density. in this study, we investigated the associations of the snps 125 g>a, 265 c>t, and 298 g>a on fy gene and the snp -33t>c on gata box with the vivax malaria parasitic density in inhabitants of amazon state, brazil. verifications of p. vivax, as well as the definiti ... | 2010 | 20162434 |
| microsatellite loci: determining the genetic variability of plasmodium vivax. | to describe the genetic diversity of plasmodium vivax isolates from different areas in the brazilian amazon using 11 polymorphic microsatellites and to evaluate the correlation between microsatellite variation and repeat array length. | 2010 | 20406424 |
| reactive case detection for plasmodium vivax malaria elimination in rural amazonia. | malaria burden in brazil has reached its lowest levels in 35 years and plasmodium vivax now accounts for 84% of cases countrywide. targeting residual malaria transmission entrenched in the amazon is the next major challenge for ongoing elimination efforts. better strategies are urgently needed to address the vast reservoir of asymptomatic p. vivax carriers in this and other areas approaching malaria elimination. | 2016 | 27941968 |
| challenges for malaria elimination in brazil. | brazil currently contributes 42 % of all malaria cases reported in the latin america and the caribbean, a region where major progress towards malaria elimination has been achieved in recent years. in 2014, malaria burden in brazil (143,910 microscopically confirmed cases and 41 malaria-related deaths) has reached its lowest levels in 35 years, plasmodium falciparum is highly focal, and the geographic boundary of transmission has considerably shrunk. transmission in brazil remains entrenched in t ... | 2016 | 27206924 |
| declining malaria transmission in rural amazon: changing epidemiology and challenges to achieve elimination. | in recent years, considerable success in reducing its incidence has been achieved in brazil, leading to a relative increase in the proportion of cases caused by plasmodium vivax, considered a harder-to-eliminate parasite. this study aim is to describe the transmission dynamics and associated risk factors in a rural settlement area in the western brazilian amazon. | 2016 | 27165432 |
| malaria in brazil: an overview. | malaria is still a major public health problem in brazil, with approximately 306,000 registered cases in 2009, but it is estimated that in the early 1940s, around six million cases of malaria occurred each year. as a result of the fight against the disease, the number of malaria cases decreased over the years and the smallest numbers of cases to-date were recorded in the 1960s. from the mid-1960s onwards, brazil underwent a rapid and disorganized settlement process in the amazon and this migrato ... | 2010 | 20433744 |
| cost effectiveness of optimal® rapid diagnostic test for malaria in remote areas of the amazon region, brazil. | in areas with limited structure in place for microscopy diagnosis, rapid diagnostic tests (rdt) have been demonstrated to be effective. | 2010 | 20937094 |
| concurrent dengue and malaria in the amazon region. | the amazon region has extensive forested areas and natural ecosystems, providing favorable conditions for the existence of innumerous arboviruses. over 200 arboviruses have been isolated in brazil and about 40 are associated with human disease. four out of 40 are considered to be of public health importance in brazil: dengue viruses (1-4), oropouche, mayaro and yellow fever. along with these viruses, about 98% of the malaria cases are restricted to the legal amazon region. | 2010 | 21085859 |
| b cell epitope mapping and characterization of naturally acquired antibodies to the plasmodium vivax merozoite surface protein-3α (pvmsp-3α) in malaria exposed individuals from brazilian amazon. | the plasmodium vivax merozoite surface protein-3α (pvmsp-3α) is considered as a potential vaccine candidate. however, the detailed investigations of the type of immune responses induced in naturally exposed populations are necessary. therefore, we aim to characterize the naturally induced antibody to pvmsp-3α in 282 individuals with different levels of exposure to malaria infections residents in brazilian amazon. pvmsp3 specific antibodies (iga, igg and igg subclass) to five recombinant proteins ... | 2011 | 21215342 |
| evaluation of the naturally acquired antibody immune response to the pv200l n-terminal fragment of plasmodium vivax merozoite surface protein-1 in four areas of the amazon region of brazil. | frequency and levels of igg antibodies to an n-terminal fragment of the plasmodium vivax msp-1 (pv200l) protein, in individuals naturally exposed to malaria in four endemic areas of brazil, were evaluated by enzyme-linked immunosorbent assay. plasma samples of 261 p. vivax-infected individuals from communities of macapá, novo repartimento, porto velho, and plácido de castro in the amazonian region with different malaria transmission intensities. a high mean number of studied individuals (89.3%) ... | 2011 | 21292879 |
| gestational malaria associated to plasmodium vivax and plasmodium falciparum placental mixed-infection followed by foetal loss: a case report from an unstable transmission area in brazil. | gestational malaria is a multi-factorial syndrome leading to poor outcomes for both the mother and foetus. although an unusual increasing in the number of hospitalizations caused by plasmodium vivax has been reported in brazil, mortality is rarely observed. this is a report of a gestational malaria case that occurred in the city of manaus (amazonas state, brazil) and resulted in foetal loss. the patient presented placental mixed-infection by plasmodium vivax and plasmodium falciparum after diagn ... | 2011 | 21708032 |
| survivorship of anopheles darlingi (diptera: culicidae) in relation with malaria incidence in the brazilian amazon. | we performed a longitudinal study of adult survival of anopheles darlingi, the most important vector in the amazon, in a malarigenous frontier zone of brazil. survival rates were determined from both parous rates and multiparous dissections. anopheles darlingi human biting rates, daily survival rates and expectation of life where higher in the dry season, as compared to the rainy season, and were correlated with malaria incidence. the biting density of mosquitoes that had survived long enough fo ... | 2011 | 21857927 |
| adherence to plasmodium vivax malaria treatment in the brazilian amazon region. | abstract: background: patients' adherence to malaria treatment is an important factor in determining the therapeutic response to anti-malarial drugs. it contributes to the patient's complete recovery and prevents the emergence of parasite resistance to anti-malarial drugs. in brazil, the low compliance with malaria treatment probably explains the large number of plasmodium vivax malaria relapses observed in the past years. the goal of this study was to estimate the proportion of patients adheri ... | 2011 | 22165853 |
| chemoresistance of plasmodium falciparum and plasmodium vivax parasites in brazil: consequences on disease morbidity and control. | in brazil, malaria still remains a clinically important febrile syndrome for local populations and travelers, occurring mostly in the amazon basin. this review aims to report the main efforts employed to control this disease since the 1940s and the emergence of plasmodium falciparum and plasmodium vivax chemoresistance to chloroquine and sulphadoxine-pyrimethamine among other drugs. additionally, in vivo, in vitro and molecular studies as well as malaria chemoresistance consequences on disease m ... | 2011 | 21881770 |
| analysis of the genetic variability of pvmsp-3α among plasmodium vivax in brazilian field isolates. | reliable molecular markers are essential for a better understanding of the molecular epidemiology of plasmodium vivax, which is a neglected human malaria parasite. the aim of this study was to analyze the genetic diversity of p. vivax isolates from the brazilian amazon using polymerase chain reaction-restriction fragment length polymorphism (pcr-rflp) analysis of the highly polymorphic merozoite surface protein-3alpha (pvmsp-3α) gene. to accomplish this, 60 isolates of p. vivax from different en ... | 2011 | 21881754 |
| reduction of incidence and relapse or recrudescence cases of malaria in the western region of the brazilian amazon. | malaria is one of the major parasitic diseases in the state of rondônia, located in the western brazilian amazon. the basic treatment scheme for this disease is chloroquine and primaquine. this study evaluated the epidemiological profile of malaria in rondônia between 2008 and 2012. | 2014 | 25212083 |
| Amazonian malaria: Asymptomatic human reservoirs, diagnostic challenges, environmentally driven changes in mosquito vector populations, and the mandate for sustainable control strategies. | Across the Americas and the Caribbean, nearly 561,000 slide-confirmed malaria infections were reported officially in 2008. The nine Amazonian countries accounted for 89% of these infections; Brazil and Peru alone contributed 56% and 7% of them, respectively. Local populations of the relatively neglected parasite Plasmodium vivax, which currently accounts for 77% of the regional malaria burden, are extremely diverse genetically and geographically structured. At a time when malaria elimination is ... | 2011 | 22015425 |
| Pharmaceutical services for endemic situations in the Brazilian Amazon: organization of services and prescribing practices for Plasmodium vivax and Plasmodium falciparum non-complicated malaria in high-risk municipalities. | ABSTRACT: | 2011 | 22050832 |
| plasmodium vivax landscape in brazil: scenario and challenges. | brazil is the largest country of latin america, with a considerable portion of its territoritory within the malaria-endemic amazon region in the north. furthermore, a considerable portion of its territory is located within the amazon region in the north. as a result, brazil has reported half of the total malaria cases in the americas in the last four decades. recent progress in malaria control has been accompanied by an increasing proportion of plasmodium vivax, underscoring a need for a better ... | 2016 | 27708190 |
| integrated vector management targeting anopheles darlingi populations decreases malaria incidence in an unstable transmission area, in the rural brazilian amazon. | studies on vector behaviour should be conducted in order to evaluate the effectiveness of vector control measures on malaria protection in endemic areas of latin america, where p. vivax predominates. this work aims to investigate the fauna of anopheline mosquitoes and verify the impact of integrated vector management in two colonization projects in the careiro municipality, western brazilian amazon. | 2012 | 23088224 |
| natural plasmodium infection in monkeys in the state of rondônia (brazilian western amazon). | simian malaria is still an open question concerning the species of plasmodium parasites and species of new world monkeys susceptible to the parasites. in addition, the lingering question as to whether these animals are reservoirs for human malaria might become important especially in a scenario of eradication of the disease. to aid in the answers to these questions, monkeys were surveyed for malaria parasite natural infection in the amazonian state of rondônia, brazil, a state with intense envir ... | 2013 | 23731624 |
| experimental plasmodium vivax infection of key anopheles species from the brazilian amazon. | anopheles darlingi is the major malaria vector in countries located in the amazon region. anopheles aquasalis and anopheles albitarsis s.l. are also proven vectors in this region. anopheles nuneztovari s.l. and anopheles triannulatus s.l. were found infected with plasmodium vivax; however, their status as vectors is not yet well defined. knowledge of susceptibility of amazon anopheline populations to plasmodium infection is necessary to better understand their vector capacity. laboratory coloniz ... | 2013 | 24359307 |
| epidemiology of disappearing plasmodium vivax malaria: a case study in rural amazonia. | new frontier settlements across the amazon basin pose a major challenge for malaria elimination in brazil. here we describe the epidemiology of malaria during the early phases of occupation of farming settlements in remansinho area, brazilian amazonia. we examine the relative contribution of low-density and asymptomatic parasitemias to the overall plasmodium vivax burden over a period of declining transmission and discuss potential hurdles for malaria elimination in remansinho and similar settin ... | 2014 | 25166263 |
| prevalence and risk factors associated to pruritus in plasmodium vivax patients using chloroquine in the brazilian amazon. | chloroquine-induced pruritus has been described as a common adverse event in african patients being treated for plasmodium falciparum malaria, and has been associated with treatment discontinuation in this setting. in latin america, where plasmodium vivax is the most common species causing malaria and chloroquine is still used as the first-line schizonticidal for treating this parasite infection, there are no reports on chloroquine-induced pruritus. this study aimed to estimate the frequency of ... | 2013 | 23906614 |
| cross-reactive anti-pfclag9 antibodies in the sera of asymptomatic parasite carriers of plasmodium vivax. | the pfclag9 has been extensively studied because their immunogenicity. thereby, the gene product is important for therapeutics interventions and a potential vaccine candidate. antibodies against synthetic peptides corresponding to selected sequences of the plasmodium falciparum antigen pfclag9 were found in sera of falciparum malaria patients from rondônia, in the brazilian amazon. much higher antibody titres were found in semi-immune and immune asymptomatic parasite carriers than in subjects su ... | 0 | 23440122 |
| effect of artesunate-mefloquine fixed-dose combination in malaria transmission in amazon basin communities. | studies in south-east asia have suggested that early diagnosis and treatment with artesunate (as) and mefloquine (mq) combination therapy may reduce the transmission of plasmodium falciparum malaria and the progression of mq resistance. | 2012 | 22905900 |
| risk factors and characterization of plasmodium vivax-associated admissions to pediatric intensive care units in the brazilian amazon. | plasmodium vivax is responsible for a significant proportion of malaria cases worldwide and is increasingly reported as a cause of severe disease. the objective of this study was to characterize severe vivax disease among children hospitalized in intensive care units (icus) in the western brazilian amazon, and to identify risk factors associated with disease severity. | 2012 | 22523591 |
| towards a precise test for malaria diagnosis in the brazilian amazon: comparison among field microscopy, a rapid diagnostic test, nested pcr, and a computational expert system based on artificial neural networks. | accurate malaria diagnosis is mandatory for the treatment and management of severe cases. moreover, individuals with asymptomatic malaria are not usually screened by health care facilities, which further complicates disease control efforts. the present study compared the performances of a malaria rapid diagnosis test (rdt), the thick blood smear method and nested pcr for the diagnosis of symptomatic malaria in the brazilian amazon. in addition, an innovative computational approach was tested for ... | 2010 | 20459613 |
| [malaria among women aged 10 to 49 years, according to sivep-malaria, manaus, state of amazonas, 2003-2006]. | the sivep-malaria epidemiological surveillance information system has been in use for notification of malaria cases diagnosed in brazil since 2003. this study analyzed malaria cases notified among women aged 10 to 49 years between 2003 and 2006, according to the presence or absence of pregnancy. | 2010 | 20563501 |
| severe rhabdomyolysis caused by plasmodium vivax malaria in the brazilian amazon. | severe rhabdomyolysis (creatine phosphokinase = 29,400 u/l) developed in a 16-year-old boy from manaus, brazil, after he started treatment with chloroquine for infection with plasmodium vivax. treatment led to myoglobinuria and acute renal failure. after hemodialysis, the patient improved and a muscle biopsy specimen showed no myophosphorylase or deaminase deficiency. this case of rhabdomyolysis associated with p. vivax infection showed no comorbidities. the pathogenesis is still unclear. althou ... | 2010 | 20682866 |
| severe plasmodium vivax malaria, brazilian amazon. | we describe a case series of 17 patients hospitalized in manaus (western brazilian amazon) with pcr-confirmed plasmodium vivax infection who were treated with chloroquine and primaquine. the major complications were jaundice and severe anemia. no in vivo chloroquine resistance was detected. these data help characterize the clinical profile of severe p. vivax malaria in latin america. | 2010 | 20875292 |
| in vitro and in vivo anti-malarial activity of plants from the brazilian amazon. | the anti-malarials quinine and artemisinin were isolated from traditionally used plants (cinchona spp. and artemisia annua, respectively). the synthetic quinoline anti-malarials (e.g. chloroquine) and semi-synthetic artemisinin derivatives (e.g. artesunate) were developed based on these natural products. malaria is endemic to the amazon region where plasmodium falciparum and plasmodium vivax drug-resistance is of concern. there is an urgent need for new anti-malarials. traditionally used amazoni ... | 2015 | 26682750 |
| a systematic review on malaria sero-epidemiology studies in the brazilian amazon: insights into immunological markers for exposure and protection. | considerable success in reducing malaria incidence and mortality has been achieved in brazil, leading to discussions over the possibility of moving towards elimination. however, more than reporting and counting clinical cases, elimination will require the use of efficient tools and strategies for measuring transmission dynamics and detecting the infectious reservoir as the primary indicators of interest for surveillance and evaluation. because acquisition and maintenance of anti-malarial antibod ... | 2017 | 28270152 |
| malaria and other febrile diseases among travellers: the experience of a reference centre located outside the brazilian amazon region. | malaria is endemic in countries located in tropical and sub-tropical regions. the increasing flow of domestic and international travellers has made malaria a relevant health problem even in non-endemic regions. malaria has been described as the main diagnosis among travellers presenting febrile diseases after returning from tropical countries. in brazil, malaria transmission occurs mainly in the amazon region. outside this area, malaria transmission is of low magnitude. | 2016 | 27230739 |
| costs associated with malaria in pregnancy in the brazilian amazon, a low endemic area where plasmodium vivax predominates. | information on costs associated with malaria in pregnancy (mip) in low transmission areas where plasmodium vivax predominates is so far missing. this study estimates health system and patient costs of mip in the brazilian amazon. | 2016 | 27031515 |
| dispensing and determinants of non-adherence to treatment for non complicated malaria caused by plasmodium vivax and plasmodium falciparum in high-risk municipalities in the brazilian amazon. | in brazil, 99.7 % of malaria cases occur in the amazon region. although the number of cases is decreasing, the country accounted for almost 60 % of cases in the americas region, in 2013. novel approaches for malaria treatment open the possibility of eliminating the disease, but suboptimal dispensing and lack of adherence influence treatment outcomes. the aim of this paper is to show the results on dispensing practices, non-adherence and determinants of non-adherence to treatment of non-complicat ... | 2015 | 26611324 |
| basic sanitation, socioeconomic conditions, and degree of risk for the presence and maintenance of malaria in a low-transmission area in the brazilian amazon. | this study aimed to evaluate basic sanitation and socioeconomic indicators, reported cases of malaria, and risk of contracting malaria in the ananindeua municipality, state of pará. | 2015 | 26516967 |
| ultrasound findings in pregnant women with uncomplicated vivax malaria in the brazilian amazon: a cohort study. | during pregnancy, plasmodium falciparum-induced malaria can cause placental lesions and intrauterine growth restriction (iugr). there are few published studies on plasmodium vivax-induced malaria in pregnancy. ultrasound is an efficient method for evaluating foetal biometry and placenta. the present study aimed to investigate the occurrence of increased placental thickness, foetal biometry and the amniotic fluid via ultrasound in a cohort of pregnant women with vivax malaria in manaus, amazonas, ... | 2015 | 25889425 |
| large-scale drivers of malaria and priority areas for prevention and control in the brazilian amazon region using a novel multi-pathogen geospatial model. | most of the malaria burden in the americas is concentrated in the brazilian amazon but a detailed spatial characterization of malaria risk has yet to be undertaken. | 2014 | 25412882 |
| imported malaria in a non-endemic area: the experience of the university of campinas hospital in the brazilian southeast. | although malaria in brazil almost exclusively occurs within the boundaries of the amazon region, some concerns are raised regarding imported malaria to non-endemic areas of the country, notably increased incidence of complications due to delayed diagnoses. however, although imported malaria in brazil represents a major health problem, only a few studies have addressed this subject. | 2014 | 25047177 |
| genetic diversity of msp1 block 2 of plasmodium vivax isolates from manaus (central brazilian amazon). | the diversity of msp1 in both plasmodium falciparum and p. vivax is presumed be associated to parasite immune evasion. in this study, we assessed genetic diversity of the most variable domain of vaccine candidate n-terminal pvmsp1 (block 2) in field isolates of manaus. forty-seven blood samples the polymorphism of pvmsp1 block 2 generates four fragment sizes. in twenty-eight of them, sequencing indicated seven haplotypes of pvmsp1 block 2 circulating among field isolates. evidence of striking ex ... | 2014 | 24741614 |
| plasmodium vivax and plasmodium falciparum ex vivo susceptibility to anti-malarials and gene characterization in rondônia, west amazon, brazil. | chloroquine (cq), a cost effective antimalarial drug with a relatively good safety profile and therapeutic index, is no longer used by itself to treat patients with plasmodium falciparum due to cq-resistant strains. p. vivax, representing over 90% of malaria cases in brazil, despite reported resistance, is treated with cq as well as with primaquine to block malaria transmission and avoid late p. vivax malaria relapses. resistance to cq and other antimalarial drugs influences malaria control, thu ... | 2014 | 24581308 |
| use of a colorimetric (deli) test for the evaluation of chemoresistance of plasmodium falciparum and plasmodium vivax to commonly used anti-plasmodial drugs in the brazilian amazon. | the emergence and spread of plasmodium falciparum and plasmodium vivax resistance to available anti-malarial drugs represents a major drawback in the control of malaria and its associated morbidity and mortality. the aim of this study was to evaluate the chemoresistance profile of p. falciparum and p. vivax to commonly used anti-plasmodial drugs in a malaria-endemic area in the brazilian amazon. | 2013 | 23937727 |
| asymptomatic infection with plasmodium falciparum and plasmodium vivax in the brazilian amazon basin: to treat or not to treat? | in this study, we determined whether the treatment of asymptomatic parasites carriers (apcs), which are frequently found in the riverside localities of the brazilian amazon that are highly endemic for malaria, would decrease the local malaria incidence by decreasing the overall pool of parasites available to infect mosquitoes. in one village, the treatment of the 19 plasmodium falciparum-infected apcs identified among the 270 residents led to a clear reduction (z = -2.39, p = 0.017) in the incid ... | 2012 | 22850952 |
| malaria outside the amazon region: natural plasmodium infection in anophelines collected near an indigenous village in the vale do rio branco, itanhaém, sp, brazil. | a few cases of plasmodium vivax malaria in which anophelines of subgenus kerteszia were incriminated as vectors have been reported outside the amazon region, in the atlantic forest. this study was carried out near an indigenous guarani village in the curucutu reserve, an environmental protection area in the municipality of itanhaém in the state of são paulo, brazil, on november 30, 2009, february 18, 2010, april 29, 2010 and may 26, 2010. mosquitoes were collected along the route to the guarani ... | 2013 | 22989665 |