| study on the natural history of malaria in areas of the rondonia state-brazil and problems related to its control. | | 1988 | 3065908 |
| [biology of amazonian anopheles. xii. occurrence of anopheles species, transmission dynamics and malaria control in the urban area of ariquemes (rondônia)]. | | 1988 | 3065910 |
| 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 |
| natural malaria infections in anophelines in rondonia state, brazilian amazon. | the use of an immunoassay for the detection of plasmodium falciparum and p. vivax circumsporozoite (cs) antigens in anophelines has recently incriminated other malaria vectors besides anopheles darlingi in the brazilian amazon. in this study we analyzed 12,336 field-collected anophelines from endemic areas in rondonia for plasmodial infection. sixty-one specimens from 6 species were positive: 47 an. darlingi, 5 an. triannulatus, 4 an. albitarsis, 2 an. braziliensis, 2 an. strodei, and 1 an. oswa ... | 1990 | 2200290 |
| second form in a segment of the merozoite surface protein 1 gene of plasmodium vivax among isolates from rondônia (brazil). | | 1992 | 1518527 |
| 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 |
| 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 |
| modern immunological approaches to assess malaria transmission and immunity and to diagnose plasmodial infection. | the present paper reviews our recent data concerning the use of immunological methods employing monoclonal antibodies and synthetic peptides to study malaria transmission and immunity and to diagnose plasmodial infection. as concerns malaria transmission, we studied the main vectors of human malaria and the plasmodial species transmitted in endemic areas of rondônia state, brazil. the natural infection of anopheline was evaluated by immunoradiometric assay (irma) using monoclonal antibodies to a ... | 1992 | 1342707 |
| 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 |
| the dynamics of transmission and spatial distribution of malaria in riverside areas of porto velho, rondônia, in the amazon region of brazil. | the study area in rondônia was the site of extensive malaria epidemic outbreaks in the 19(th) and 20(th) centuries related to environmental impacts, with large immigration flows. the present work analyzes the transmission dynamics of malaria in these areas to propose measures for avoiding epidemic outbreaks due to the construction of two hydroelectric power plants. a population based baseline demographic census and a malaria prevalence follow up were performed in two river side localities in the ... | 2010 | 20169070 |
| naturally acquired humoral and cellular immune responses to plasmodium vivax merozoite surface protein 9 in northwestern amazon individuals. | antibody and t-cell reactivities to plasmodium vivax merozoite surface protein 9 (pvmsp9) were evaluated in a cross-sectional study of individuals naturally exposed to malaria infections living in ribeirinha, a native riverine community and in colina, a transmigrant community, rondonia, brazil. the antibody responses to pvmsp9-ririiand pvmsp9-nt domains in ribeirinha were higher compared with colina and correlated with age and time of malaria exposure. igg2 was most prevalent for pvmsp9-rii in b ... | 2008 | 18832003 |
| severe plasmodium vivax malaria exhibits marked inflammatory imbalance. | despite clinical descriptions of severe vivax malaria cases having been reported, data regarding immunological and inflammatory patterns are scarce. in this report, the inflammatory and immunological status of both mild and severe vivax malaria cases are compared in order to explore immunopathological events in this disease. | 2010 | 20070895 |
| [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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| high prevalence of asymptomatic plasmodium vivax and plasmodium falciparum infections in native amazonian populations. | the epidemiology of malaria in 2 riverine localities in rondĵnia, brazilian western amazĵnia, was assessed by a 1-year study at portuchuelo, and a cross-sectional survey at riverine communities at rio machado (= ji-parana). plasmodium spp. infections were diagnosed by light microscopy and by polymerase chain reaction (pcr) amplification of ribosomal dna. pcr was 6-7 times more efficient than microscopy for detecting plasmodial infections. both plasmodium vivax and plasmodium falciparum infection ... | 2002 | 12224567 |
| 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 |
| prevalence and levels of igg and igm antibodies against plasmodium falciparum and p. vivax in blood donors from rondônia, brazilian amazon. | antibodies of igg and igm isotypes reacting with plasmodium falciparum and p. vivax thicksmear antigens were searched for by the indirect fluorescent antibody test (ifat) in a random sample of 230 blood donors at the transfusion centre of porto velho (hemeron), rondônia state, western brazilian amazon. a high prevalence of igg seropositivity (32% against p. falciparum, 24% against p. vivax and 37% against either p. falciparum or p. vivax antigens) was detected among them, despite the fact that c ... | 1993 | 8107588 |
| [malaria in the region of campinas, são paulo, brazil, 1980 to 1994]. | according to epidemiological data, from 1980 to 1994, 2,781 cases of malaria were registered as follows: dir xii-campinas (49.3%), dir xv-piracicaba (41.3%) and dir xx-são joão da boa vista (9.4%). the plasmodium vivax was found in 70.6% of the patients; plasmodium falciparum in 25.4% and 4% of the patients presented a mixed infection. the epidemiological classification showed that 95% of the cases came from the states of rondônia, mato grosso and par. the masculine sex, between the age of 20 to ... | 2000 | 10881119 |
| hypoendemic malaria in rondonia (brazil, western amazon region): seasonal variation and risk groups in an urban locality. | a longitudinal epidemiologic survey (1989-1991) plus a cross-sectional parasitologic, clinical, and sociodemographic survey (july-october 1990) were conducted in candeias do jamary, a village with approximately 7,000 inhabitants in rondonia, brazil. analysis of the results revealed hypoendemic malaria with a complex epidemiology. plasmodium vivax predominated over p. falciparum infections while infections with p. malariae were absent. malaria is present throughout the year but was clearly season ... | 1996 | 8702019 |
| longitudinal study of naturally acquired humoral immune responses against the merozoite surface protein 1 of plasmodium vivax in patients from rondonia, brazil. | a longitudinal study on the naturally acquired humoral immune responses against the merozoite surface protein 1 of plasmodium vivax (pvmsp-1) was performed in malaria patients from the brazilian amazon region of rondonia. we have previously cloned and expressed a recombinant protein, icb2-5, that encodes 508 amino acids from the n-terminal portion of the pvmsp-1 protein. this affinity-purified polypeptide was tested by an enzyme-linked immunosorbent assay in a one-year longitudinal study using s ... | 1993 | 8372960 |
| characterization of naturally acquired human igg responses against the n-terminal region of the merozoite surface protein 1 of plasmodium vivax. | the primary structure of the merozoite surface protein 1 of plasmodium vivax (pvmsp-1) revealed the existence of conserved and polymorphic blocks of the protein among different plasmodium species. to characterize the naturally acquired igg antibody responses to the pvmsp-1 molecule, the entire n-terminal portion of this protein was expressed as 10 overlapping glutathione s-transferase fusion proteins. the affinity-purified recombinant products were tested by enzyme-linked immunosorbent assay and ... | 1994 | 8059917 |
| unstable hypoendemic malaria in rondonia (western amazon region, brazil): epidemic outbreaks and work-associated incidence in an agro-industrial rural settlement. | a longitudinal study was conducted from january 1991 to january 1992 on the urupa farm, a rural agro-industrial forestry settlement in rondonia state (western amazon region, brazil) to define the parasitologic and clinical profile of malaria. three cross-sectional, parasitologic, and clinical surveys were performed. in the intervals between surveys, malaria cases were monitored by twice a week medical visits to the farm and permanent local surveillance. the population of residents was approximat ... | 1994 | 8059911 |
| infection of anopheles darlingi fed on patients infected with plasmodium vivax before and during treatment with chloroquine in costa marques, rondonia, brazil. | patients with asexual and sexual parasites of plasmodium vivax were treated orally with 600 mg of chloroquine diphosphate at hour zero, followed by 300 mg at 8, 24 and 48 hr. anopheles darlingi were fed before the first dose (-0.5 hr) and at 0.5, 1, 2, 4, 6, 8, 9, 10, 11, 12, 20, 24, 36, 48, 60, and 72 hr later. mosquitoes were examined for oocysts on day 8 and sporozoites on day 15 after infection. the frequency of infected mosquitoes and the mean number of oocysts were lower in mosquitoes that ... | 1991 | 1951855 |
| comparative susceptibility of anopheline mosquitoes in rondonia, brazil to infection by plasmodium vivax. | seven anopheline species from costa marques, rondonia, brazil were compared with anopheles darlingi for susceptibility to infection by plasmodium vivax. laboratory-reared f1 progeny of field-collected an. darlingi and the test anopheline species were fed at the same time on the same patients, all of whom had gametocytes in peripheral blood before treatment. mosquitoes were dissected on day 8 after infection for oocysts and on days 14-16 after infection for sporozoites. the mean numbers of p. viv ... | 1991 | 1951854 |
| 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 |
| promiscuous t-cell epitopes of plasmodium merozoite surface protein 9 (pvmsp9) induces ifn-gamma and il-4 responses in individuals naturally exposed to malaria in the brazilian amazon. | plasmodium vivax merozoite surface protein (pvmsp9) stimulates both cellular and humoral immune responses in individuals who are naturally infected by this parasite species. to identify immunodominant human t-cell epitopes in pvmsp9, we used the mhc class ii binding peptide prediction algorithm propred. eleven synthetic peptides representing predicted putative promiscuous t-cell epitopes were tested in ifn-gamma and il-4 elispot assays using peripheral blood mononuclear cells (pbmc) derived from ... | 2010 | 20189487 |
| 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 |
| 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 |
| 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 |
| hepatitis b infection is associated with asymptomatic malaria in the brazilian amazon. | areas that are endemic for malaria are also highly endemic for hepatitis b virus (hbv) infection. nevertheless, it is unknown whether hbv infection modifies the clinical presentation of malaria. this study aimed to address this question. | 2011 | 21625634 |