Abstract:
BACKGROUND:Long regarded as an epicenter of drug-resistant malaria, Southeast Asia continues to provide new challenges to the control of Plasmodium falciparum malaria. Recently, resistance to the artemisinin combination therapy partner drug piperaquine has been observed in multiple locations across Southeast Asia. Genetic studies have identified single nucleotide polymorphisms as well as copy number variations in the plasmepsin 2 and plasmepsin 3 genes, which encode haemoglobin-degrading proteases that associate with clinical and in vitro piperaquine resistance. RESULTS:To accurately and quickly determine the presence of copy number variations in the plasmepsin 2/3 genes in field isolates, this study developed a quantitative PCR assay using TaqMan probes. Copy number estimates were validated using a separate SYBR green-based quantitative PCR assay as well as a novel PCR-based breakpoint assay to detect the hybrid gene product. Field samples from 2012 to 2015 across three sites in Cambodia were tested using DNA extracted from dried blood spots and whole blood to monitor the extent of plasmepsin 2/3 gene amplifications, as well as amplifications in the multidrug resistance transporter 1 gene (pfmdr1), a marker of mefloquine resistance. This study found high concordance across all methods of copy number detection. For samples derived from dried blood spots, a success rate greater than 80% was found in each assay, with more recent samples performing better. Evidence of extensive plasmepsin 2/3 copy number amplifications was observed in Pursat (94%, 2015) (Western Cambodia) and Preah Vihear (87%, 2014) (Northern Cambodia), and lower levels in Ratanakiri (16%, 2014) (Eastern Cambodia). A shift was observed from two copies of plasmepsin 2 in Pursat in 2013 to three copies in 2014-2015 (25% to 64%). Pfmdr1 amplifications were absent in all samples from Preah Vihear and Ratanakiri in 2014 and absent in Pursat in 2015. CONCLUSIONS:The multiplex TaqMan assay is a robust tool for monitoring both plasmepsin 2/3 and pfmdr1 copy number variations in field isolates, and the SYBR-green and breakpoint assays are useful for monitoring plasmepsin 2/3 amplifications. This study shows increasing levels of plasmepsin 2 copy numbers across Cambodia from 2012 to 2015 and a complete reversion of multicopy pfmdr1 parasites to single copy parasites in all study locations.
journal_name
Malar Jjournal_title
Malaria journalauthors
Ansbro MR,Jacob CG,Amato R,Kekre M,Amaratunga C,Sreng S,Suon S,Miotto O,Fairhurst RM,Wellems TE,Kwiatkowski DPdoi
10.1186/s12936-020-03249-xsubject
Has Abstractpub_date
2020-05-13 00:00:00pages
181issue
1issn
1475-2875pii
10.1186/s12936-020-03249-xjournal_volume
19pub_type
杂志文章相关文献
MALARIA JOURNAL文献大全abstract:BACKGROUND:Primaquine (PQ) prevents relapses of vivax malaria but may induce severe haemolysis in glucose-6-phosphate dehydrogenase (G6PD) deficient patients. Data on the safety of primaquine in infants are limited. METHODS:A retrospective, hospital-based cohort study of infants aged 1-12 months with vivax malaria was...
journal_title:Malaria journal
pub_type: 杂志文章
doi:10.1186/s12936-019-2745-7
更新日期:2019-04-02 00:00:00
abstract:BACKGROUND:The erythrocytic stage of Plasmodium falciparum parasites in humans is clinically important, as the parasites at this growth stage causes malarial symptoms. Most of the currently available anti-malarial drugs target this stage, but the emergence and spread of parasites resistant to anti-malarial drugs are a ...
journal_title:Malaria journal
pub_type: 杂志文章
doi:10.1186/s12936-019-2642-0
更新日期:2019-01-14 00:00:00
abstract:BACKGROUND:This study aimed to identify factors at individual and community level influencing insecticide-treated net (ITN) usage among groups of women of childbearing age (WOCBA) in Malawi. METHODS:Factors influencing ITN usage in Malawi were assessed through interviews with 16,130 WOCBA (15-49 years) across 850 comm...
journal_title:Malaria journal
pub_type: 杂志文章
doi:10.1186/s12936-018-2522-z
更新日期:2018-10-19 00:00:00
abstract:BACKGROUND:The circumsporozoite protein (CS protein) on the malaria parasites in mosquitoes plays an important role in sporogony in mosquitoes. The RTS,S/AS01 malaria vaccine candidate, which has shown significant efficacy against clinical malaria in a large Phase 3 trial, targets the Plasmodium falciparum CS protein, ...
journal_title:Malaria journal
pub_type: 杂志文章,多中心研究
doi:10.1186/1475-2875-13-263
更新日期:2014-07-09 00:00:00
abstract:BACKGROUND:Insecticide-treated nets (ITN) and long-lasting insecticidal treated nets (LLIN) are important means of malaria prevention. Although there is consensus regarding their importance, there is uncertainty as to which delivery strategies are optimal for dispensing these life saving interventions. A targeted mass ...
journal_title:Malaria journal
pub_type: 杂志文章
doi:10.1186/1475-2875-9-173
更新日期:2010-06-18 00:00:00
abstract:BACKGROUND:In a malaria-endemic area the distribution of patients is neither constant in time nor homogeneous in space. The WHO recommends the stratification of malaria risk on a fine geographical scale. In the village of Cacao in French Guiana, the study of the spatial and temporal distribution of malaria cases, durin...
journal_title:Malaria journal
pub_type: 杂志文章
doi:10.1186/1475-2875-12-90
更新日期:2013-03-11 00:00:00
abstract:BACKGROUND:The objective of this project was to achieve high, sustainable levels of net coverage in a village in rural Tanzania by combining free distribution of long-lasting insecticide-impregnated nets (LLINs) with community-tailored education. In Tanzania, malaria is the leading cause of morbidity and mortality. Alt...
journal_title:Malaria journal
pub_type: 杂志文章
doi:10.1186/1475-2875-8-315
更新日期:2009-12-31 00:00:00
abstract:BACKGROUND:Plasmodium falciparum readily develops resistance to the anti-folates pyrimethamine and proguanil via a characteristic set of mutations in the dihydrofolate reductase (PfDHFR) gene that leads to reduced competitive drug binding at the enzyme's active site. Analogous mutations can be found in the DHFR gene in...
journal_title:Malaria journal
pub_type: 杂志文章
doi:10.1186/1475-2875-9-65
更新日期:2010-03-02 00:00:00
abstract::The Global Technical Strategy 2016-2030 of the World Health Organization (WHO) has the ambitious goal of malaria being eliminated from at least 35 countries by 2030. However, in areas with once-stable malaria transmission, the reservoir of human infection may be intermittently symptomatic or fully silent yet still lea...
journal_title:Malaria journal
pub_type: 杂志文章
doi:10.1186/s12936-019-2906-8
更新日期:2019-08-22 00:00:00
abstract:BACKGROUND:Rapid elimination of Plasmodium falciparum malaria in Cambodia is a goal with both national and international significance. Transmission of malaria in Cambodia is limited to forest environments, and the main population at risk consists of forest-goers who rely on forest products for income or sustenance. The...
journal_title:Malaria journal
pub_type: 杂志文章
doi:10.1186/s12936-020-03572-3
更新日期:2021-01-20 00:00:00
abstract::India has committed to eliminate malaria by 2030. The national framework for malaria elimination released by the Government of India plans to achieve this goal through strategic planning in a phased manner. Since vector control is a major component of disease management and vector elimination, it requires a thorough u...
journal_title:Malaria journal
pub_type: 杂志文章,评审
doi:10.1186/s12936-019-3011-8
更新日期:2019-12-03 00:00:00
abstract:BACKGROUND:The RTS,S/AS malaria candidate vaccine is being developed with the intent to be delivered, if approved, through the Expanded Programme on Immunization (EPI) of the World Health Organization. Safety, immunogenicity and efficacy of the RTS,S/AS02(D) vaccine candidate when integrated into a standard EPI schedul...
journal_title:Malaria journal
pub_type: 杂志文章,随机对照试验
doi:10.1186/1475-2875-12-11
更新日期:2013-01-08 00:00:00
abstract::The Rethinking Malaria Leadership Forum, held at Harvard Business School in February 2017 with collaboration of the Barcelona Institute for Global Health and the Swiss Tropical and Public Health Institute, identified this training gap as a high priority for both analysis and action. The gap in human resource training ...
journal_title:Malaria journal
pub_type: 杂志文章
doi:10.1186/s12936-018-2199-3
更新日期:2018-01-25 00:00:00
abstract:BACKGROUND:Individual malaria interventions provide only partial protection in most epidemiological situations. Thus, there is a need to investigate whether combining interventions provides added benefit in reducing mortality and morbidity from malaria. The potential benefits of combining IPT in children (IPTc) with ho...
journal_title:Malaria journal
pub_type: 杂志文章,随机对照试验
doi:10.1186/1475-2875-10-2
更新日期:2011-01-07 00:00:00
abstract:BACKGROUND:Rapid diagnostic tests (RDTs) for histidine rich protein 2 (HRP2) are often used to determine whether persons with fever should be treated with anti-malarials. However, Plasmodium falciparum parasites with a deletion of the hrp2 gene yield false-negative RDTs and there are concerns the sensitivity of HRP2-ba...
journal_title:Malaria journal
pub_type: 杂志文章
doi:10.1186/s12936-017-1768-1
更新日期:2017-03-20 00:00:00
abstract:BACKGROUND:Arthropod vectors of disease may encounter more than one infected host during the course of their lifetime. The consequences of super-infection to parasite development are rarely investigated, but may have substantial epidemiological and evolutionary consequences. METHODS:Using a rodent malaria model system...
journal_title:Malaria journal
pub_type: 杂志文章
doi:10.1186/1475-2875-3-12
更新日期:2004-05-19 00:00:00
abstract::Plasmodium falciparum infections present novel challenges for vaccine development, including parasite replication dynamics not previously encountered for viral pathogens, and enormous diversity in target antigens. These challenges are illustrated by using a mathematical model to describe the association between the pr...
journal_title:Malaria journal
pub_type: 杂志文章
doi:10.1186/1475-2875-12-280
更新日期:2013-08-08 00:00:00
abstract:BACKGROUND:Complex malaria infections are defined as those containing more than one genetically distinct lineage of Plasmodium parasite. Complexity of infection (COI) is a useful parameter to estimate from patient blood samples because it is associated with clinical outcome, epidemiology and disease transmission rate. ...
journal_title:Malaria journal
pub_type: 杂志文章
doi:10.1186/1475-2875-14-4
更新日期:2015-01-19 00:00:00
abstract:BACKGROUND:Malaria elimination efforts can be undermined by imported malaria infections. Imported infections are classified based on travel history. METHODS:A genetic strategy was applied to better understand the contribution of imported infections and to test for local transmission in the very low prevalence region o...
journal_title:Malaria journal
pub_type: 杂志文章
doi:10.1186/s12936-020-03346-x
更新日期:2020-08-03 00:00:00
abstract:BACKGROUND:Over the last decade, the incidence of confirmed malaria has declined significantly in Nepal. The aim of this paper is to assess the spatio-temporal distribution of malaria and its association with climatic factors and vector control interventions in two high-risk districts of Nepal. METHODS:Hotspot analysi...
journal_title:Malaria journal
pub_type: 杂志文章
doi:10.1186/1475-2875-13-457
更新日期:2014-11-25 00:00:00
abstract:BACKGROUND:The north coast of Guadalcanal has some of the most intense malaria transmission in the Solomon Islands. And, there is a push for intensified vector control in Guadalcanal, to improve the livelihood of residents and to minimize the number of cases, which are regularly exported to the rest of the country. The...
journal_title:Malaria journal
pub_type: 杂志文章
doi:10.1186/1475-2875-13-56
更新日期:2014-02-15 00:00:00
abstract:BACKGROUND:In view of the need to continuously feed the pipeline with new anti-malarial agents adapted to differentiated and more stringent target product profiles (e.g., new modes of action, transmission-blocking activity or long-duration chemo-protection), a chemical library consisting of more than 250,000 compounds ...
journal_title:Malaria journal
pub_type: 杂志文章
doi:10.1186/1475-2875-13-190
更新日期:2014-05-27 00:00:00
abstract:BACKGROUND:Most malaria rapid diagnostic tests (RDTs) use HRP2 detection, including Paracheck-Pf(R), but their utility is limited by persistent false positivity after treatment. PLDH-based tests become negative more quickly, but sensitivity has been reported below the recommended standard of 90%. A new pLDH test, CareS...
journal_title:Malaria journal
pub_type: 杂志文章
doi:10.1186/1475-2875-9-28
更新日期:2010-01-21 00:00:00
abstract:BACKGROUND:Isolation of a concentrated, living preparation of malarial parasite-infected red blood cells (PRBCs) that have low contamination of white blood cells (WBCs) facilitates research on the molecular, biochemical and immunological aspects of malarial parasites. This is currently carried out by a two-step method,...
journal_title:Malaria journal
pub_type: 杂志文章
doi:10.1186/1475-2875-3-7
更新日期:2004-03-17 00:00:00
abstract:BACKGROUND:The current target of universal access to long-lasting, insecticide-treated nets (LLIN) is 80% coverage to reduce malaria deaths by 75% by 2015. So far, campaigns have been the main channel for large-scale delivery of LLINs, however the World Health Organization has recommended that equal priority should be ...
journal_title:Malaria journal
pub_type: 杂志文章
doi:10.1186/1475-2875-11-327
更新日期:2012-09-13 00:00:00
abstract:BACKGROUND:The relationship between the burden of uncomplicated malaria and transmission intensity is unclear and a better understanding of this relationship is important for the implementation of intervention programmes. METHODS:A 6-month longitudinal study monitoring risk factors for anaemia and febrile malaria epis...
journal_title:Malaria journal
pub_type: 杂志文章
doi:10.1186/1475-2875-3-26
更新日期:2004-07-28 00:00:00
abstract:BACKGROUND:Drug resistance determination for Plasmodium falciparum infections are important to determining the type of treatment to be given. Besides in vivo experiments, molecular methods, such as sequencing and PCR, are now increasingly being used. Here a cheaper alternative to sequencing or the use of multiplex 5'nu...
journal_title:Malaria journal
pub_type: 杂志文章
doi:10.1186/1475-2875-9-134
更新日期:2010-05-21 00:00:00
abstract:BACKGROUND:Counts of malaria parasites in peripheral blood are important to assess severity of Plasmodium falciparum malaria. Thin and thick smears are routinely used for this purpose. METHODS:In this study the Binax NOW Malaria Test, an easy-to-perform rapid diagnostic test, with Histidine Rich Protein-2 (HRP-2) and ...
journal_title:Malaria journal
pub_type: 杂志文章,多中心研究
doi:10.1186/1475-2875-10-300
更新日期:2011-10-14 00:00:00
abstract:BACKGROUND:Traditional medicine is readily available in Tanzania, and local terms like degedege is widely used for malaria-like illnesses, often associated with supernatural forces. Malaria prevention and intervention efforts can benefit from policy-makers' awareness of local perceptions and beliefs in the rural areas ...
journal_title:Malaria journal
pub_type: 杂志文章
doi:10.1186/1475-2875-13-200
更新日期:2014-05-28 00:00:00
abstract:BACKGROUND:Plasmodium vivax is a major cause of malaria and is still primarily treated with chloroquine. Chloroquine inhibits the polymerization of haem to inert haemozoin. Free haem monomers are thought to catalyze oxidative damage to the Plasmodium spp. trophozoite, the stage when haemoglobin catabolism is maximal. H...
journal_title:Malaria journal
pub_type: 杂志文章
doi:10.1186/1475-2875-7-94
更新日期:2008-05-27 00:00:00