| plasmodium vivax vk247 and vk210 circumsporozoite proteins in anopheles mosquitoes from andoas, peru. | anopheles mosquitoes captured in andoas, peru, a plasmodium vivax-endemic area in the peruvian amazon region, contained both vk210 and vk247 p. vivax circumsporozoite (cs) proteins. approximately 0.9% of the 4,403 mosquitoes tested by enzyme-linked immunosorbent assay were positive; 28% and 72% of the positive mosquitoes contained vk210 and vk247 cs proteins, respectively. these findings correlate strongly with a recent report of the presence of antibodies in residents of this area that recogniz ... | 1993 | 8510119 |
| clustered local transmission and asymptomatic plasmodium falciparum and plasmodium vivax malaria infections in a recently emerged, hypoendemic peruvian amazon community. | there is a low incidence of malaria in iquitos, peru, suburbs detected by passive case-detection. this low incidence might be attributable to infections clustered in some households/regions and/or undetected asymptomatic infections. | 2005 | 15975146 |
| plasmodium falciparum and plasmodium vivax infections in the peruvian amazon: propagation of complex, multiple allele-type infections without super-infection. | outcrossing potential between plasmodium parasites is defined by the population-level diversity (pld) and complexity of infection (coi). there have been few studies of pld and coi in low transmission regions. since the 1995-1998 peruvian amazon epidemic, there has been sustained transmission with < 0.5 p. falciparum and < 1.6 p. vivax infections/person/year. using weekly active case detection, we described pld by heterozygosity (h(e)) and coi using p. falciparum pfmsp1-b2 and p. vivax pvmsp3alph ... | 2009 | 19996422 |
| prevalence and risk of plasmodium falciparum and p. vivax malaria among pregnant women living in the hypoendemic communities of the peruvian amazon. | the amazon region of iquitos, peru is hypoendemic for plasmodium vivax and p. falciparum. there is limited information regarding the epidemiology of malaria during pregnancy in this region. passive surveillance for clinical malaria among pregnant women was conducted in eight health posts in 2004 and 2005. community-based active surveillance was conducted to determine the incidence of malarial infection among pregnant women in the community of zungarococha in 2004 and 2005. passive surveillance d ... | 2007 | 17827359 |
| epidemiology and spatial analysis of malaria in the northern peruvian amazon. | a retrospective surveillance study was conducted to examine the micro-geographic variation of malaria incidence in three malaria-endemic communities in the northern peruvian amazon. the annual malaria risk rate (per 100) ranged from 38% to 47% for plasmodium vivax and from 15% to 18% for p. falciparum. spatial clusters were found for p. vivax in padre cocha, manacamiri, and zungaro cocha, and for p. falciparum only in padre cocha. spatial-temporal clusters showed that the highest monthly number ... | 2006 | 17172396 |
| experimental infection of the neotropical malaria vector anopheles darlingi by human patient-derived plasmodium vivax in the peruvian amazon. | malaria transmission from humans to mosquitoes is modulated by human host immune factors. understanding mechanisms by which the human host response may impair parasite infectivity for mosquitoes has direct implications for the development of transmission-blocking vaccines. we hypothesized that despite a low transmission intensity of malaria in the peruvian amazon region of iquitos, transmission-blocking immunity against plasmodium vivax might be common, given an unexpectedly high proportion of a ... | 2006 | 17038681 |
| zinc and iron supplementation and malaria, diarrhea, and respiratory infections in children in the peruvian amazon. | iron and zinc deficiencies are common in developing countries and supplementation is one way of reversing these deficiencies. the objective of this randomized, placebo-controlled clinical trial was to identify the effect of daily supplementation with iron, zinc, and iron plus zinc on the morbidity experience of 855 children 0.5-15 years of age in peru. single nutrient supplementation with zinc reduced diarrhea morbidity by 23% in all children. in older children (more than five years of age), iro ... | 2006 | 16837718 |
| chloroquine-resistant plasmodium vivax malaria in peru. | reports from several sites in south america suggest the presence of isolated cases of chloroquine-resistant plasmodium vivax malaria. to investigate the possibility of chloroquine-resistant p. vivax in peru, we conducted 28-day in vivo drug efficacy trials at three sites in the amazon region and one site on the northern pacific coast between 1998 and 2001. a total of 242 patients between the ages of 2 and 60 years were enrolled (177 from the amazon region and 65 from the northern coast). all sub ... | 2003 | 14695094 |
| endemic malaria in the peruvian amazon region of iquitos. | a cross-sectional study was conducted in the peruvian amazon to test the hypothesis that a reservoir of asymptomatic malaria parasitemic patients would form the basis for continuing malaria endemicity in the region. active surveillance yielded a plasmodium spp. slide-positive prevalence of 4.2% (43 of 1,023) and a polymerase chain reaction (pcr)-positive prevalence of 17.6% (144 of 819). plasmodium vivax prevalence was 2.9% and 14.2% while plasmodium falciparum prevalence was 1.3% and 2.6% by mi ... | 2003 | 12932096 |
| practical aspects of in vivo antimalarial drug efficacy testing in the americas. | the world health organization (who) has developed guidelines for in vivo antimalarial drug efficacy testing for plasmodium falciparum and plasmodium vivax in areas with low-to-moderate transmission, such as the americas. these guidelines are used widely by ministries of health and national malaria control programs to assess the efficacy of their first-line and second-line drugs for the treatment of malaria and to provide the information necessary to update national malaria treatment policies. fo ... | 2003 | 12875285 |
| malaria in brazil, colombia, peru and venezuela: current challenges in malaria control and elimination. | in spite of significant progress towards malaria control and elimination achieved in south america in the 2000s, this mosquito-transmitted tropical disease remains an important public health concern in the region. most malaria cases in south america come from amazon rain forest areas in northern countries, where more than half of malaria is caused by plasmodium vivax, while plasmodium falciparum malaria incidence has decreased in recent years. this review discusses current malaria data, policies ... | 2017 | 28676055 |
| micro-heterogeneity of malaria transmission in the peruvian amazon: a baseline assessment underlying a population-based cohort study. | understanding the dynamics of malaria transmission in diverse endemic settings is key for designing and implementing locally adapted and sustainable control and elimination strategies. a parasitological and epidemiological survey was conducted in september-october 2012, as a baseline underlying a 3-year population-based longitudinal cohort study. the aim was to characterize malaria transmission patterns in two contrasting ecological rural sites in the peruvian amazon, lupuna (lup), a riverine en ... | 2017 | 28778210 |
| high degree of plasmodium vivax diversity in the peruvian amazon demonstrated by tandem repeat polymorphism analysis. | molecular tools to distinguish strains of plasmodium vivax are important for studying the epidemiology of malaria transmission. two sets of markers-tandem repeat (tr) polymorphisms and msp3α-were used to study plasmodium vivax in patients in the peruvian amazon region of iquitos. of 110 patients, 90 distinct haplotypes were distinguished using 9 tr markers. an msp3α polymerase chain reaction-restriction fragment length polymorphism (pcr-rflp) using hhai and alui revealed 8 and 9 profiles, respec ... | 2012 | 22492139 |
| assessment of an automated capillary system for plasmodium vivax microsatellite genotyping. | several platforms have been used to generate the primary data for microsatellite analysis of malaria parasite genotypes. each has relative advantages but share a limitation of being time- and cost-intensive. a commercially available automated capillary gel cartridge system was assessed in the microsatellite analysis of plasmodium vivax diversity in the peruvian amazon. | 2015 | 26293655 |
| rapid diagnostic tests for malaria diagnosis in the peruvian amazon: impact of pfhrp2 gene deletions and cross-reactions. | in the peruvian amazon, plasmodium falciparum and plasmodium vivax malaria are endemic in rural areas, where microscopy is not available. malaria rapid diagnostic tests (rdts) provide quick and accurate diagnosis. however, pfhrp2 gene deletions may limit the use of histidine-rich protein-2 (pfhrp2) detecting rdts. further, cross-reactions of p. falciparum with p. vivax-specific test lines and vice versa may impair diagnostic specificity. | 2012 | 22952633 |
| [congenital malaria in a hospital in iquitos, peru]. | to determine the frequency and clinical features of newborns with congenital malaria in the hospital de apoyo of iquitos in the peruvian amazon. | 2015 | 26338383 |
| population genetics of plasmodium vivax in the peruvian amazon. | characterizing the parasite dynamics and population structure provides useful information to understand the dynamic of transmission and to better target control interventions. despite considerable efforts for its control, vivax malaria remains a major health problem in peru. in this study, we have explored the population genetics of plasmodium vivax isolates from iquitos, the main city in the peruvian amazon, and 25 neighbouring peri-urban as well as rural villages along the iquitos-nauta road. | 2016 | 26766548 |
| human host-derived cytokines associated with plasmodium vivax transmission from acute malaria patients to anopheles darlingi mosquitoes in the peruvian amazon. | infection of mosquitoes by humans is not always successful in the setting of patent gametocytemia. this study tested the hypothesis that pro- or anti-inflammatory cytokines are associated with transmission of plasmodium vivax to anopheles darlingi mosquitoes in experimental infection. blood from adults with acute, non-severe p. vivax malaria was fed to laboratory-reared f1 an. darlingi mosquitoes. a panel of cytokines at the time of mosquito infection was assessed in patient sera and levels comp ... | 2013 | 23478585 |
| microgeographical differences of plasmodium vivax relapse and re-infection in the peruvian amazon. | to determine the magnitude of plasmodium vivax relapsing malaria in rural amazonia, we carried out a study in four sites in northeastern peru. polymerase chain reaction-restriction fragment length polymorphism of pvmsp-3α and tandem repeat (tr) markers were compared for their ability to distinguish relapse versus reinfection. of 1,507 subjects with p. vivax malaria, 354 developed > 1 episode during the study; 97 of 354 (27.5%) were defined as relapse using pvmsp-3α alone. the addition of tr poly ... | 2013 | 23836566 |
| population structure and spatio-temporal transmission dynamics of plasmodium vivax after radical cure treatment in a rural village of the peruvian amazon. | despite the large burden of plasmodium vivax, little is known about its transmission dynamics. this study explored the population structure and spatio-temporal dynamics of p. vivax recurrent infections after radical cure in a two-year cohort study carried out in a rural community of the peruvian amazon. | 2014 | 24393454 |
| 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 |
| plasmodium vivax sub-patent infections after radical treatment are common in peruvian patients: results of a 1-year prospective cohort study. | there is an increasing body of literature reporting treatment failure of the currently recommended radical treatment of plasmodium vivax infections. as p. vivax is the main malaria species outside the african continent, emerging tolerance to its radical treatment regime could have major consequences in countries like peru, where 80% of malaria cases are due to p. vivax. here we describe the results of a 1-year longitudinal follow up of 51 confirmed p. vivax patients living around iquitos, peruvi ... | 2011 | 21297986 |
| on the validity of self-reports and indirect reports to ascertain malaria prevalence in settings of hypoendemicity. | self-reports are commonly used to ascertain malaria prevalence in epidemiological studies conducted in settings where laboratory diagnosis is impractical. most studies, however, do not use self-report per se, but indirect report, where one respondent provides responses for all household members. studies also vary in terms of the time frame used for this ascertainment. the aim of our research was to determine the validity of self-report and indirect report in ascertaining malaria prevalence over ... | 2010 | 21257247 |
| multilocus genotyping reveals high heterogeneity and strong local population structure of the plasmodium vivax population in the peruvian amazon. | peru is one of the latin american countries with the highest malaria burden, mainly due to plasmodium vivax infections. however, little is known about p. vivax transmission dynamics in the peruvian amazon, where most malaria cases occur. the genetic diversity and population structure of p. vivax isolates collected in different communities around iquitos city, the capital of the peruvian amazon, was determined. | 2010 | 20525233 |
| adherence to 7-day primaquine treatment for the radical cure of p. vivax in the peruvian amazon. | despite being free of charge, treatment adherence to 7-day primaquine for the radical cure of plasmodium vivax was estimated at 62.2% among patients along the iquitos-nauta road in the peruvian amazon. the principal reason for non-adherence was the perceived adverse effects related to local humoral illness conceptions that hold that malaria produces a hot state of body, which is further aggravated by the characteristically hot medical treatment. notably, patients were willing to adhere to the fi ... | 2010 | 20519594 |