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Ren N, Kuang YM, Tang QL, Cheng L, Zhang CH, Yang ZQ, He YS, Zhu YC. High Incidence of Malaria Along the Sino-Burmese Border Is Associated With Polymorphisms of CR1, IL-1A, IL-4R, IL-4, NOS, and TNF, But Not With G6PD Deficiency. Medicine (Baltimore) 2015; 94:e1681. [PMID: 26448013 PMCID: PMC4616751 DOI: 10.1097/md.0000000000001681] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Malaria is highly endemic in Yunnan Province, China, with the incidence of malaria being highest along the Sino-Burmese border. The aim of our study was to determine whether genetic polymorphisms are associated with the prevalence of malaria among Chinese residents of the Sino-Burmese border region. Fourteen otherwise healthy people with glucose-6-phosphate dehydrogenase (G6PD) deficiency, 50 malaria patients, and 67 healthy control subjects were included in our cross-sectional study. We analyzed the frequency of the G3093T and T520C single-nucleotide polymorphisms (SNPs) of CR1. Logistic regression was used to calculate the prevalence odds ratio (POR) and 95% confidence interval (CI) of malaria for the T520C SNP of CR1 and SNPs of G6PD, IL-4, IL-4R, IL-1A, NOS, CD40LG, TNF, and LUC7L. The frequency of the 3093T/3093T genotype of CR1 in the malaria group (0.16) was significantly higher than that in the control group (0.045, P < 0.05), and significantly lower than that in the G6PD deficiency group (0.43, P < 0.01). The frequency of the 520T/520T genotype of CR1 was significantly higher in the malaria patients (0.78) than that in the control group (0.67, P < 0.05) and G6PD-deficiency group (0.36, P < 0.05). The T allele of the T520C variant of CR1 was significantly associated with the prevalence of malaria (POR: 1.460; 95% CI: 0.703-3.034). Polymorphisms of G6PD did not significantly influence the prevalence malaria (P > 0.05). A GTGTGTC haplotype consisting of IL-1A (rs17561), IL-4 (rs2243250), TNF (rs1800750), IL-4R (rs1805015), NOS (rs8078340), CD40LG (rs1126535), and LUC7L (rs1211375) was significantly associated with the prevalence of malaria (POR: 1.822, 95% CI: 0.998-3.324). The 3093G/3093G and 520T/520T genotypes are the predominant genetic variants of CR1 among Chinese residents near the Sino-Burmese border, and the T allele of T520C is associated with the prevalence of malaria in this region. Although G6PD deficiency does not protect against malaria, it may diminish the association between malaria and the CR1 polymorphisms in this population. The GTGTGTC haplotype is also associated with the prevalence of malaria in this region.
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Affiliation(s)
- Na Ren
- From the Department of Biochemistry and Molecular Biology (NR, LC, C-HZ, Q-LT, Z-QY, Y-SH, Y-CZ); and First Affiliated Hospital, Kunming Medical University, Kunming, Yunnan, PR China (Y-MK)
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152
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Alderton S, Noble J, Schaten K, Welburn SC, Atkinson PM. Exploiting Human Resource Requirements to Infer Human Movement Patterns for Use in Modelling Disease Transmission Systems: An Example from Eastern Province, Zambia. PLoS One 2015; 10:e0139505. [PMID: 26421926 PMCID: PMC4589342 DOI: 10.1371/journal.pone.0139505] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 09/12/2015] [Indexed: 11/18/2022] Open
Abstract
In this research, an agent-based model (ABM) was developed to generate human movement routes between homes and water resources in a rural setting, given commonly available geospatial datasets on population distribution, land cover and landscape resources. ABMs are an object-oriented computational approach to modelling a system, focusing on the interactions of autonomous agents, and aiming to assess the impact of these agents and their interactions on the system as a whole. An A* pathfinding algorithm was implemented to produce walking routes, given data on the terrain in the area. A* is an extension of Dijkstra’s algorithm with an enhanced time performance through the use of heuristics. In this example, it was possible to impute daily activity movement patterns to the water resource for all villages in a 75 km long study transect across the Luangwa Valley, Zambia, and the simulated human movements were statistically similar to empirical observations on travel times to the water resource (Chi-squared, 95% confidence interval). This indicates that it is possible to produce realistic data regarding human movements without costly measurement as is commonly achieved, for example, through GPS, or retrospective or real-time diaries. The approach is transferable between different geographical locations, and the product can be useful in providing an insight into human movement patterns, and therefore has use in many human exposure-related applications, specifically epidemiological research in rural areas, where spatial heterogeneity in the disease landscape, and space-time proximity of individuals, can play a crucial role in disease spread.
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Affiliation(s)
- Simon Alderton
- Institute of Complex System Simulation, School of Electronics and Computer Science, University of Southampton, Southampton, United Kingdom
- Geography and Environment, Faculty of Social and Human Sciences, University of Southampton, Southampton, United Kingdom
- * E-mail:
| | - Jason Noble
- Institute of Complex System Simulation, School of Electronics and Computer Science, University of Southampton, Southampton, United Kingdom
| | - Kathrin Schaten
- Division of Pathway Medicine and Centre for Infectious Diseases, School of Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh, United Kingdom
| | - Susan C. Welburn
- Division of Pathway Medicine and Centre for Infectious Diseases, School of Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh, United Kingdom
| | - Peter M. Atkinson
- Faculty of Science and Technology, Engineering Building, Lancaster University, Lancaster, United Kingdom
- Faculty of Geosciences, University of Utrecht, Heidelberglaan 2, 3584 CS Utrecht, The Netherlands
- School of Geography, Archaeology and Palaeoecology, Queen’s University Belfast, Northern Ireland, United Kingdom
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153
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Chitunhu S, Musenge E. Direct and indirect determinants of childhood malaria morbidity in Malawi: a survey cross-sectional analysis based on malaria indicator survey data for 2012. Malar J 2015; 14:265. [PMID: 26152223 PMCID: PMC4495946 DOI: 10.1186/s12936-015-0777-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Accepted: 06/29/2015] [Indexed: 01/06/2023] Open
Abstract
Background Children under the age of five are most vulnerable to malaria (malaria is a major health challenge in sub-Saharan Africa) with a child dying every 30 s from malaria. Hampered socio-economic development, poverty, diseconomies of scale, marginalization, and exploitation are associated with malaria. Therefore establishing determinants of malaria in affected sub-Saharan populations is important in order to come up with informed interventions that will be effective in malaria control. Methods The study was a cross-sectional survey design based on data from the Malawi 2012 Malaria indicator Survey obtained from Demographic and Health Survey (DHS) programme website. The outcome variable was positive laboratory-based blood smear result for malaria in children less than 5 years, after an initial positive rapid malaria diagnostic test done at the homestead. Statistical modelling was done using survey logistic regression as well as generalized structural equation modelling (G-SEM) to analyse direct and indirect effects of malaria. Results The propensity score matched data had 1 325 children with 367 (27.7%) having blood smear positive malaria. Female children made up approximately 53% of the total study participants. Child related variables (age, haemoglobin and position in household) and household wealth index were significant directly and indirectly. Further on G-SEM based multivariable analysis showed socio-economic status (SES) [Odds ratio (OR) = 0.96, 95% Confidence interval (CI) = 0.92, 0.99] and primary level of education [OR = 0.50, 95% CI = 0.32, 0.77] were important direct and indirect determinants of malaria morbidity. Conclusion Socio-economic status and education are important factors that influence malaria control. These factors need to be taken into consideration when planning malaria control programmes in order to have effective programmes. Direct and indirect effect modelling can also provide an alternative modelling technique that incorporates surrogate confounders that may not be significant when modelled directly. This holistic approach is useful and will help in improving malaria control.
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Affiliation(s)
- Simangaliso Chitunhu
- Division of Epidemiology and Biostatistics, School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, 27 St Andrews' Road, Parktown, Johannesburg, 2193, South Africa.
| | - Eustasius Musenge
- Division of Epidemiology and Biostatistics, School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, 27 St Andrews' Road, Parktown, Johannesburg, 2193, South Africa.
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154
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Koepfli C, Rodrigues PT, Antao T, Orjuela-Sánchez P, Van den Eede P, Gamboa D, van Hong N, Bendezu J, Erhart A, Barnadas C, Ratsimbasoa A, Menard D, Severini C, Menegon M, Nour BYM, Karunaweera N, Mueller I, Ferreira MU, Felger I. Plasmodium vivax Diversity and Population Structure across Four Continents. PLoS Negl Trop Dis 2015; 9:e0003872. [PMID: 26125189 PMCID: PMC4488360 DOI: 10.1371/journal.pntd.0003872] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 06/02/2015] [Indexed: 01/12/2023] Open
Abstract
Plasmodium vivax is the geographically most widespread human malaria parasite. To analyze patterns of microsatellite diversity and population structure across countries of different transmission intensity, genotyping data from 11 microsatellite markers was either generated or compiled from 841 isolates from four continents collected in 1999–2008. Diversity was highest in South-East Asia (mean allelic richness 10.0–12.8), intermediate in the South Pacific (8.1–9.9) Madagascar and Sudan (7.9–8.4), and lowest in South America and Central Asia (5.5–7.2). A reduced panel of only 3 markers was sufficient to identify approx. 90% of all haplotypes in South Pacific, African and SE-Asian populations, but only 60–80% in Latin American populations, suggesting that typing of 2–6 markers, depending on the level of endemicity, is sufficient for epidemiological studies. Clustering analysis showed distinct clusters in Peru and Brazil, but little sub-structuring was observed within Africa, SE-Asia or the South Pacific. Isolates from Uzbekistan were exceptional, as a near-clonal parasite population was observed that was clearly separated from all other populations (FST>0.2). Outside Central Asia FST values were highest (0.11–0.16) between South American and all other populations, and lowest (0.04–0.07) between populations from South-East Asia and the South Pacific. These comparisons between P. vivax populations from four continents indicated that not only transmission intensity, but also geographical isolation affect diversity and population structure. However, the high effective population size results in slow changes of these parameters. This persistency must be taken into account when assessing the impact of control programs on the genetic structure of parasite populations. Plasmodium vivax is the predominant malaria parasite in Latin America, Asia and the South Pacific. Different factors are expected to shape diversity and population structure across continents, e.g. transmission intensity which is much lower in South America as compared to Southeast-Asia and the South Pacific, or geographical isolation of P. vivax populations in the South Pacific. We have compiled data from 841 isolates from South and Central America, Africa, Central Asia, Southeast-Asia and the South Pacific typed with a panel of 11 microsatellite markers. Diversity was highest in Southeast-Asia, where transmission is intermediate-high and migration of infected hosts is high, and lowest in South America and Central Asia where malaria transmission is low and focal. Reducing the panel of microsatellites showed that 2–6 markers are sufficient for genotyping for most drug trials and epidemiological studies, as these markers can identify >90% of all haplotypes. Parasites clustered according to continental origin, with high population differentiation between South American and Central Asian populations and the other populations, and lowest differences between Southeast-Asia and the South Pacific. Current attempts to reduce malaria transmission might change this pattern, but only after transmission is reduced for an extended period of time.
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Affiliation(s)
- Cristian Koepfli
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- Walter and Eliza Hall Institute, Parkville, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Priscila T. Rodrigues
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Tiago Antao
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Pamela Orjuela-Sánchez
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Peter Van den Eede
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Dionicia Gamboa
- Instituto de Medicina Tropical Alexander Von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Nguyen van Hong
- National Institute of Malariology, Parasitology, and Entomology, Hanoi, Vietnam
| | - Jorge Bendezu
- Instituto de Medicina Tropical Alexander Von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Annette Erhart
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Céline Barnadas
- Walter and Eliza Hall Institute, Parkville, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Arsène Ratsimbasoa
- Immunology Unit, Institut Pasteur de Madagascar, Antananarivo, Madagascar
| | - Didier Menard
- Institut Pasteur de Cambodge, Malaria Molecular Epidemiology Unit, Phnom Penh, Cambodia
| | - Carlo Severini
- Department of Infectious, Parasitic and Immunomediated Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Michela Menegon
- Department of Infectious, Parasitic and Immunomediated Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Bakri Y. M. Nour
- Department of Parasitology, Blue Nile National Institute for Communicable Diseases, University of Gezira, Wad Medani, Sudan
| | - Nadira Karunaweera
- Department of Parasitology, Faculty of Medicine, University of Colombo, Sri Lanka
| | - Ivo Mueller
- Walter and Eliza Hall Institute, Parkville, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Australia
- Barcelona Centre for International Health Research, Barcelona, Spain
| | - Marcelo U. Ferreira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Ingrid Felger
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- * E-mail:
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155
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Desai KR, Rajput DK, Patel PB, Highland HN. Ameliorative Effects of Curcumin on Artesunate-Induced Subchronic Toxicity in Testis of Swiss Albino Male Mice. Dose Response 2015; 13:1559325815592393. [PMID: 26673878 PMCID: PMC4674183 DOI: 10.1177/1559325815592393] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
India is one of the endemic areas where control of malaria has become a formidable task. Artesunate is the current antimalarial drug used to treat malaria, especially chloroquine resistant. The objective of the present study was to investigate the dose-dependent effect of oral administration of artesunate on the oxidative parameters in testes of adult male Swiss albino mice and ameliorative efficacy of curcumin, a widely used antioxidant. An oral dose of 150 mg/kg body weight (bwt; low dose) and 300 mg/kg bwt (high dose) of artesunate was administered for a period of 45 days to male mice, and ameliorative efficacy of curcumin was also assessed. The results revealed that artesunate caused significant alteration in oxidative parameters in dose-dependent manner. Administration of artesunate brought about significant decrease in activities of superoxide dismutase, glutathione, glutathione peroxidase, and glutathione reductase, whereas lipid peroxidation and glutathione-S-transferase activity were found to be significantly increased. The results obtained show that oxidative insult is incurred upon the intracellular antioxidant system of testis tissue by artesunate treatment. Further, administration of curcumin at the dose level of 80 mg/kg bwt along with both doses of artesunate attenuated adverse effects in male mice.
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Affiliation(s)
- Ketaki R Desai
- Department of Zoology and BMT, Gujarat University, Ahmedabad, Gujarat, India
| | | | - Pragnesh B Patel
- Department of Zoology and BMT, Gujarat University, Ahmedabad, Gujarat, India
| | - Hyacinth N Highland
- Department of Zoology and BMT, Gujarat University, Ahmedabad, Gujarat, India
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156
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Cooke MK, Kahindi SC, Oriango RM, Owaga C, Ayoma E, Mabuka D, Nyangau D, Abel L, Atieno E, Awuor S, Drakeley C, Cox J, Stevenson J. 'A bite before bed': exposure to malaria vectors outside the times of net use in the highlands of western Kenya. Malar J 2015; 14:259. [PMID: 26109384 PMCID: PMC4479228 DOI: 10.1186/s12936-015-0766-4] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 06/06/2015] [Indexed: 12/25/2022] Open
Abstract
Background The human population in the highlands of Nyanza Province, western Kenya, is subject to sporadic epidemics of Plasmodium falciparum. Indoor residual spraying (IRS) and long-lasting insecticide treated nets (LLINs) are used widely in this area. These interventions are most effective when Anopheles rest and feed indoors and when biting occurs at times when individuals use LLINs. It is therefore important to test the current assumption of vector feeding preferences, and late night feeding times, in order to estimate the extent to which LLINs protect the inhabitants from vector bites. Methods Mosquito collections were made for six consecutive nights each month between June 2011 and May 2012. CDC light-traps were set next to occupied LLINs inside and outside randomly selected houses and emptied hourly. The net usage of residents, their hours of house entry and exit and times of sleeping were recorded and the individual hourly exposure to vectors indoors and outdoors was calculated. Using these data, the true protective efficacy of nets (P*), for this population was estimated, and compared between genders, age groups and from month to month. Results Primary vector species (Anopheles funestus s.l. and Anopheles arabiensis) were more likely to feed indoors but the secondary vector Anopheles coustani demonstrated exophagic behaviour (p < 0.05). A rise in vector biting activity was recorded at 19:30 outdoors and 18:30 indoors. Individuals using LLINs experienced a moderate reduction in their overall exposure to malaria vectors from 1.3 to 0.47 bites per night. The P* for the population over the study period was calculated as 51% and varied significantly with age and season (p < 0.01). Conclusions In the present study, LLINs offered the local population partial protection against malaria vector bites. It is likely that P* would be estimated to be greater if the overall suppression of the local vector population due to widespread community net use could be taken into account. However, the overlap of early biting habit of vectors and human activity in this region indicates that additional methods of vector control are required to limit transmission. Regular surveillance of both vector behaviour and domestic human-behaviour patterns would assist the planning of future control interventions in this region. Electronic supplementary material The online version of this article (doi:10.1186/s12936-015-0766-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Mary K Cooke
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK.
| | - Sam C Kahindi
- Kenya Medical Research Institute Centre for Global Health Research/Centers for Disease Control and Prevention, Kisumu, Kenya.
| | - Robin M Oriango
- Kenya Medical Research Institute Centre for Global Health Research/Centers for Disease Control and Prevention, Kisumu, Kenya.
| | - Chrispin Owaga
- Kenya Medical Research Institute Centre for Global Health Research/Centers for Disease Control and Prevention, Kisumu, Kenya.
| | - Elizabeth Ayoma
- Kenya Medical Research Institute Centre for Global Health Research/Centers for Disease Control and Prevention, Kisumu, Kenya.
| | - Danspaid Mabuka
- Kenya Medical Research Institute Centre for Global Health Research/Centers for Disease Control and Prevention, Kisumu, Kenya.
| | - Dennis Nyangau
- Kenya Medical Research Institute Centre for Global Health Research/Centers for Disease Control and Prevention, Kisumu, Kenya.
| | - Lucy Abel
- Kenya Medical Research Institute Centre for Global Health Research/Centers for Disease Control and Prevention, Kisumu, Kenya.
| | - Elizabeth Atieno
- Kenya Medical Research Institute Centre for Global Health Research/Centers for Disease Control and Prevention, Kisumu, Kenya.
| | - Stephen Awuor
- Kenya Medical Research Institute Centre for Global Health Research/Centers for Disease Control and Prevention, Kisumu, Kenya.
| | - Chris Drakeley
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK.
| | - Jonathan Cox
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK.
| | - Jennifer Stevenson
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK. .,Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health/Macha Research Trust, Choma, Zambia.
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157
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Abstract
The effectiveness of flour fortification in reducing anaemia prevalence is equivocal. The goal was to utilise the existing national-level data to assess whether anaemia in non-pregnant women was reduced after countries began fortifying wheat flour, alone or in combination with maize flour, with at least Fe, folic acid, vitamin A or vitamin B12. Nationally representative anaemia data were identified through Demographic and Health Survey reports, the WHO Vitamin and Mineral Nutrition Information System database and other national-level nutrition surveys. Countries with at least two anaemia surveys were considered for inclusion. Within countries, surveys were excluded if altitude was not consistently adjusted for, or if the blood-draw site (e.g. capillary or venous) or Hb quantification method (e.g. HemoCue or Cyanmethaemoglobin) differed. Anaemia prevalence was modelled for countries that had pre- and post-fortification data (n 12) and for countries that never fortified flour (n 20) using logistic regression models that controlled for time effects, human development index (HDI) and endemic malaria. After adjusting for HDI and malaria, each year of fortification was associated with a 2·4 % reduction in the odds of anaemia prevalence (PR 0·976, 95 % CI 0·975, 0·978). Among countries that never fortified, no reduction in the odds of anaemia prevalence over time was observed (PR 0·999, 95 % CI 0·997, 1·002). Among both fortification and non-fortification countries, HDI and malaria were significantly associated with anaemia (P< 0·001). Although this type of evidence precludes a definitive conclusion, results suggest that after controlling for time effects, HDI and endemic malaria, anaemia prevalence has decreased significantly in countries that fortify flour with micronutrients, while remaining unchanged in countries that do not.
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158
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Dalrymple U, Mappin B, Gething PW. Malaria mapping: understanding the global endemicity of falciparum and vivax malaria. BMC Med 2015; 13:140. [PMID: 26071312 PMCID: PMC4465620 DOI: 10.1186/s12916-015-0372-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 05/18/2015] [Indexed: 11/14/2022] Open
Abstract
The mapping of malaria risk has a history stretching back over 100 years. The last decade, however, has seen dramatic progress in the scope, rigour and sophistication of malaria mapping such that its global distribution is now probably better understood than any other infectious disease. In this minireview we consider the main factors that have facilitated the recent proliferation of malaria risk mapping efforts and describe the most prominent global-scale endemicity mapping endeavours of recent years. We describe the diversification of malaria mapping to span a wide range of related metrics of biological and public health importance and consider prospects for the future of the science including its key role in supporting elimination efforts.
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Affiliation(s)
- Ursula Dalrymple
- Department of Zoology, Spatial Ecology and Epidemiology Group, University of Oxford, Tinbergen Building, Oxford, UK.
| | - Bonnie Mappin
- Department of Zoology, Spatial Ecology and Epidemiology Group, University of Oxford, Tinbergen Building, Oxford, UK.
| | - Peter W Gething
- Department of Zoology, Spatial Ecology and Epidemiology Group, University of Oxford, Tinbergen Building, Oxford, UK.
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159
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Spatial heterogeneity, host movement and mosquito-borne disease transmission. PLoS One 2015; 10:e0127552. [PMID: 26030769 PMCID: PMC4452543 DOI: 10.1371/journal.pone.0127552] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 04/16/2015] [Indexed: 11/19/2022] Open
Abstract
Mosquito-borne diseases are a global health priority disproportionately affecting low-income populations in tropical and sub-tropical countries. These pathogens live in mosquitoes and hosts that interact in spatially heterogeneous environments where hosts move between regions of varying transmission intensity. Although there is increasing interest in the implications of spatial processes for mosquito-borne disease dynamics, most of our understanding derives from models that assume spatially homogeneous transmission. Spatial variation in contact rates can influence transmission and the risk of epidemics, yet the interaction between spatial heterogeneity and movement of hosts remains relatively unexplored. Here we explore, analytically and through numerical simulations, how human mobility connects spatially heterogeneous mosquito populations, thereby influencing disease persistence (determined by the basic reproduction number R0), prevalence and their relationship. We show that, when local transmission rates are highly heterogeneous, R0 declines asymptotically as human mobility increases, but infection prevalence peaks at low to intermediate rates of movement and decreases asymptotically after this peak. Movement can reduce heterogeneity in exposure to mosquito biting. As a result, if biting intensity is high but uneven, infection prevalence increases with mobility despite reductions in R0. This increase in prevalence decreases with further increase in mobility because individuals do not spend enough time in high transmission patches, hence decreasing the number of new infections and overall prevalence. These results provide a better basis for understanding the interplay between spatial transmission heterogeneity and human mobility, and their combined influence on prevalence and R0.
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160
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Battle KE, Cameron E, Guerra CA, Golding N, Duda KA, Howes RE, Elyazar IRF, Price RN, Baird JK, Reiner RC, Smith DL, Gething PW, Hay SI. Defining the relationship between Plasmodium vivax parasite rate and clinical disease. Malar J 2015; 14:191. [PMID: 25948111 PMCID: PMC4429942 DOI: 10.1186/s12936-015-0706-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2015] [Accepted: 04/22/2015] [Indexed: 01/05/2023] Open
Abstract
Background Though essential to the development and evaluation of national malaria control programmes, precise enumeration of the clinical illness burden of malaria in endemic countries remains challenging where local surveillance systems are incomplete. Strategies to infer annual incidence rates from parasite prevalence survey compilations have proven effective in the specific case of Plasmodium falciparum, but have yet to be developed for Plasmodium vivax. Moreover, defining the relationship between P. vivax prevalence and clinical incidence may also allow levels of endemicity to be inferred for areas where the information balance is reversed, that is, incident case numbers are more widely gathered than parasite surveys; both applications ultimately facilitating cartographic estimates of P. vivax transmission intensity and its ensuring disease burden. Methods A search for active case detection surveys was conducted and the recorded incidence values were matched to local, contemporary parasite rate measures and classified to geographic zones of differing relapse phenotypes. A hierarchical Bayesian model was fitted to these data to quantify the relationship between prevalence and incidence while accounting for variation among relapse zones. Results The model, fitted with 176 concurrently measured P. vivax incidence and prevalence records, was a linear regression of the logarithm of incidence against the logarithm of age-standardized prevalence. Specific relationships for the six relapse zones where data were available were drawn, as well as a pooled overall relationship. The slope of the curves varied among relapse zones; zones with short predicted time to relapse had steeper slopes than those observed to contain long-latency relapse phenotypes. Conclusions The fitted relationships, along with appropriate uncertainty metrics, allow for estimates of clinical incidence of known confidence to be made from wherever P. vivax prevalence data are available. This is a prerequisite for cartographic-based inferences about the global burden of morbidity due to P. vivax, which will be used to inform control efforts. Electronic supplementary material The online version of this article (doi:10.1186/s12936-015-0706-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Katherine E Battle
- Spatial Ecology and Epidemiology Group, Tinbergen Building, Department of Zoology, University of Oxford, South Parks Road, Oxford, UK.
| | - Ewan Cameron
- Spatial Ecology and Epidemiology Group, Tinbergen Building, Department of Zoology, University of Oxford, South Parks Road, Oxford, UK.
| | - Carlos A Guerra
- Sanaria Institute for Global Health and Tropical Medicine, Rockville, MD, USA.
| | - Nick Golding
- Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, UK.
| | - Kirsten A Duda
- Spatial Ecology and Epidemiology Group, Tinbergen Building, Department of Zoology, University of Oxford, South Parks Road, Oxford, UK.
| | - Rosalind E Howes
- Spatial Ecology and Epidemiology Group, Tinbergen Building, Department of Zoology, University of Oxford, South Parks Road, Oxford, UK.
| | - Iqbal R F Elyazar
- Eijkman-Oxford Clinical Research Unit, Jalan Diponegoro No 69, Jakarta, Indonesia.
| | - Ric N Price
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia. .,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - J Kevin Baird
- Eijkman-Oxford Clinical Research Unit, Jalan Diponegoro No 69, Jakarta, Indonesia. .,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Robert C Reiner
- Indiana University School of Public Health, Bloomington, IN, USA. .,Fogarty International Center, National Institutes of Health, Bethesda, MD, USA.
| | - David L Smith
- Spatial Ecology and Epidemiology Group, Tinbergen Building, Department of Zoology, University of Oxford, South Parks Road, Oxford, UK. .,Sanaria Institute for Global Health and Tropical Medicine, Rockville, MD, USA. .,Fogarty International Center, National Institutes of Health, Bethesda, MD, USA.
| | - Peter W Gething
- Spatial Ecology and Epidemiology Group, Tinbergen Building, Department of Zoology, University of Oxford, South Parks Road, Oxford, UK.
| | - Simon I Hay
- Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, UK. .,Fogarty International Center, National Institutes of Health, Bethesda, MD, USA. .,Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, 98121, USA.
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161
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Van Boeckel TP, Brower C, Gilbert M, Grenfell BT, Levin SA, Robinson TP, Teillant A, Laxminarayan R. Global trends in antimicrobial use in food animals. Proc Natl Acad Sci U S A 2015; 112:5649-54. [PMID: 25792457 PMCID: PMC4426470 DOI: 10.1073/pnas.1503141112] [Citation(s) in RCA: 1869] [Impact Index Per Article: 207.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Demand for animal protein for human consumption is rising globally at an unprecedented rate. Modern animal production practices are associated with regular use of antimicrobials, potentially increasing selection pressure on bacteria to become resistant. Despite the significant potential consequences for antimicrobial resistance, there has been no quantitative measurement of global antimicrobial consumption by livestock. We address this gap by using Bayesian statistical models combining maps of livestock densities, economic projections of demand for meat products, and current estimates of antimicrobial consumption in high-income countries to map antimicrobial use in food animals for 2010 and 2030. We estimate that the global average annual consumption of antimicrobials per kilogram of animal produced was 45 mg⋅kg(-1), 148 mg⋅kg(-1), and 172 mg⋅kg(-1) for cattle, chicken, and pigs, respectively. Starting from this baseline, we estimate that between 2010 and 2030, the global consumption of antimicrobials will increase by 67%, from 63,151 ± 1,560 tons to 105,596 ± 3,605 tons. Up to a third of the increase in consumption in livestock between 2010 and 2030 is imputable to shifting production practices in middle-income countries where extensive farming systems will be replaced by large-scale intensive farming operations that routinely use antimicrobials in subtherapeutic doses. For Brazil, Russia, India, China, and South Africa, the increase in antimicrobial consumption will be 99%, up to seven times the projected population growth in this group of countries. Better understanding of the consequences of the uninhibited growth in veterinary antimicrobial consumption is needed to assess its potential effects on animal and human health.
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Affiliation(s)
- Thomas P Van Boeckel
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544;
| | - Charles Brower
- Center for Disease Dynamics, Economics & Policy, Washington, DC 20036
| | - Marius Gilbert
- Universite Libre de Bruxelles, B1050 Brussels, Belgium; Fonds National de la Recherche Scientifique, B1000 Brussels, Belgium
| | - Bryan T Grenfell
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544; Princeton Environmental Institute, Princeton, NJ 08544; Fogarty International Center, National Institutes of Health, Bethesda, MD 20892
| | - Simon A Levin
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544; Beijer Institute of Ecological Economics, 10405 Stockholm, Sweden; Resources for the Future, Washington, DC 20036;
| | | | - Aude Teillant
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544; Princeton Environmental Institute, Princeton, NJ 08544
| | - Ramanan Laxminarayan
- Center for Disease Dynamics, Economics & Policy, Washington, DC 20036; Princeton Environmental Institute, Princeton, NJ 08544; Public Health Foundation of India, New Delhi 110070, India
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162
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Abstract
Demand for animal protein for human consumption is rising globally at an unprecedented rate. Modern animal production practices are associated with regular use of antimicrobials, potentially increasing selection pressure on bacteria to become resistant. Despite the significant potential consequences for antimicrobial resistance, there has been no quantitative measurement of global antimicrobial consumption by livestock. We address this gap by using Bayesian statistical models combining maps of livestock densities, economic projections of demand for meat products, and current estimates of antimicrobial consumption in high-income countries to map antimicrobial use in food animals for 2010 and 2030. We estimate that the global average annual consumption of antimicrobials per kilogram of animal produced was 45 mg⋅kg(-1), 148 mg⋅kg(-1), and 172 mg⋅kg(-1) for cattle, chicken, and pigs, respectively. Starting from this baseline, we estimate that between 2010 and 2030, the global consumption of antimicrobials will increase by 67%, from 63,151 ± 1,560 tons to 105,596 ± 3,605 tons. Up to a third of the increase in consumption in livestock between 2010 and 2030 is imputable to shifting production practices in middle-income countries where extensive farming systems will be replaced by large-scale intensive farming operations that routinely use antimicrobials in subtherapeutic doses. For Brazil, Russia, India, China, and South Africa, the increase in antimicrobial consumption will be 99%, up to seven times the projected population growth in this group of countries. Better understanding of the consequences of the uninhibited growth in veterinary antimicrobial consumption is needed to assess its potential effects on animal and human health.
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163
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Waheed AA, Ghanchi NK, Rehman KA, Raza A, Mahmood SF, Beg MA. Vivax malaria and chloroquine resistance: a neglected disease as an emerging threat. Malar J 2015; 14:146. [PMID: 25889875 PMCID: PMC4392755 DOI: 10.1186/s12936-015-0660-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 03/20/2015] [Indexed: 11/21/2022] Open
Abstract
In Pakistan, Plasmodium vivax contributes to major malaria burden. In this case, a pregnant woman presented with P. vivax infection and which was not cleared by chloroquine, despite adequate treatment. This is probably the first confirmed case of chloroquine-resistant vivax from Pakistan, where severe malaria due to P. vivax is already an emerging problem.
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Affiliation(s)
- Anam A Waheed
- Medical College, Aga Khan University, Karachi, Pakistan.
| | - Najia K Ghanchi
- Department of Pathology and Laboratory Medicine, Aga Khan University, Stadium Road, PO Box 3500, Karachi, 74800, Pakistan.
| | - Karim A Rehman
- Medical College, Aga Khan University, Karachi, Pakistan.
| | - Afsheen Raza
- Department of Pathology and Laboratory Medicine, Aga Khan University, Stadium Road, PO Box 3500, Karachi, 74800, Pakistan.
| | - Syed F Mahmood
- Section of Adult Infectious Diseases, Department of Medicine, Aga Khan University, Stadium Road, PO Box 3500, Karachi, 74800, Pakistan.
| | - Mohammad A Beg
- Department of Pathology and Laboratory Medicine, Aga Khan University, Stadium Road, PO Box 3500, Karachi, 74800, Pakistan.
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164
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Upadhyayula SM, Mutheneni SR, Chenna S, Parasaram V, Kadiri MR. Climate drivers on malaria transmission in Arunachal Pradesh, India. PLoS One 2015; 10:e0119514. [PMID: 25803481 PMCID: PMC4372434 DOI: 10.1371/journal.pone.0119514] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 01/23/2015] [Indexed: 01/19/2023] Open
Abstract
The present study was conducted during the years 2006 to 2012 and provides information on prevalence of malaria and its regulation with effect to various climatic factors in East Siang district of Arunachal Pradesh, India. Correlation analysis, Principal Component Analysis and Hotelling's T² statistics models are adopted to understand the effect of weather variables on malaria transmission. The epidemiological study shows that the prevalence of malaria is mostly caused by the parasite Plasmodium vivax followed by Plasmodium falciparum. It is noted that, the intensity of malaria cases declined gradually from the year 2006 to 2012. The transmission of malaria observed was more during the rainy season, as compared to summer and winter seasons. Further, the data analysis study with Principal Component Analysis and Hotelling's T² statistic has revealed that the climatic variables such as temperature and rainfall are the most influencing factors for the high rate of malaria transmission in East Siang district of Arunachal Pradesh.
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Affiliation(s)
- Suryanaryana Murty Upadhyayula
- Biology Division, Council of Scientific and Industrial Research-Indian Institute of Chemical Technology, Hyderabad-500 607, India
| | - Srinivasa Rao Mutheneni
- Biology Division, Council of Scientific and Industrial Research-Indian Institute of Chemical Technology, Hyderabad-500 607, India
| | - Sumana Chenna
- Chemical Engineering Sciences, Council of Scientific and Industrial Research-Indian Institute of Chemical Technology, Hyderabad-500 607, India
| | - Vaideesh Parasaram
- Chemical Engineering Sciences, Council of Scientific and Industrial Research-Indian Institute of Chemical Technology, Hyderabad-500 607, India
| | - Madhusudhan Rao Kadiri
- Biology Division, Council of Scientific and Industrial Research-Indian Institute of Chemical Technology, Hyderabad-500 607, India
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165
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Huang JX, Xia ZG, Zhou SS, Pu XJ, Hu MG, Huang DC, Ren ZP, Zhang SS, Yang MN, Wang DQ, Wang JF. Spatio-temporal analysis of malaria vectors in national malaria surveillance sites in China. Parasit Vectors 2015; 8:146. [PMID: 25888910 PMCID: PMC4357060 DOI: 10.1186/s13071-015-0741-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 02/13/2015] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND To reveal the spatio-temporal distribution of malaria vectors in the national malaria surveillance sites from 2005 to 2010 and provide reference for the current National Malaria Elimination Programme (NMEP) in China. METHODS A 6-year longitudinal surveillance on density of malaria vectors was carried out in the 62 national malaria surveillance sites. The spatial and temporal analyses of the four primary vectors distribution were conducted by the methods of kernel k-means and the cluster distribution of the most widely distribution vector of An.sinensis was identified using the empirical mode decomposition (EMD). RESULTS Totally 4 species of Anopheles mosquitoes including An.sinensis, An.lesteri, An.dirus and An.minimus were captured with significant difference of distribution as well as density. An. sinensis was the most widely distributed, accounting for 96.25% of all collections, and its distribution was divided into three different clusters with a significant increase of density observed in the second cluster which located mostly in the central parts of China. CONCLUSION This study first described the spatio-temporal distribution of malaria vectors based on the nationwide surveillance during 2005-2010, which served as a baseline for the ongoing national malaria elimination program.
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Affiliation(s)
- Ji-Xia Huang
- College of Forestry, Beijing Forestry University, Beijing, 100083, China.
- Center of 3S Technology and Mapping, College of Forestry, Beijing Forestry University, Beijing, 100083, China.
- LREIS, Institute of Geographic Science and Natural Resource Research, Chinese Academy of Sciences, Beijing, China.
| | - Zhi-Gui Xia
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Center for Malaria, Schistosomiasis and Filariasis, Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, People's Republic of China.
| | - Shui-Sen Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Center for Malaria, Schistosomiasis and Filariasis, Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, People's Republic of China.
| | - Xiao-Jun Pu
- Geospatial Information Sciences in the School of Economic, Political and Policy Sciences at The University of Texas in Dallas, Richardson, USA.
| | - Mao-Gui Hu
- LREIS, Institute of Geographic Science and Natural Resource Research, Chinese Academy of Sciences, Beijing, China.
- Key Laboratory of Surveillance and Early Warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, 102206, China.
| | - Da-Cang Huang
- School of Geographical Science, Northeast Normal University, Changchun, 130024, China.
| | - Zhou-Peng Ren
- LREIS, Institute of Geographic Science and Natural Resource Research, Chinese Academy of Sciences, Beijing, China.
- Key Laboratory of Surveillance and Early Warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, 102206, China.
| | - Shao-Sen Zhang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Center for Malaria, Schistosomiasis and Filariasis, Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, People's Republic of China.
| | - Man-Ni Yang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Center for Malaria, Schistosomiasis and Filariasis, Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, People's Republic of China.
| | - Duo-Quan Wang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Center for Malaria, Schistosomiasis and Filariasis, Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, People's Republic of China.
| | - Jin-Feng Wang
- LREIS, Institute of Geographic Science and Natural Resource Research, Chinese Academy of Sciences, Beijing, China.
- Key Laboratory of Surveillance and Early Warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, 102206, China.
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166
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Plasmodium falciparum chloroquine resistance transporter is a H+-coupled polyspecific nutrient and drug exporter. Proc Natl Acad Sci U S A 2015; 112:3356-61. [PMID: 25733858 DOI: 10.1073/pnas.1417102112] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Extrusion of chloroquine (CQ) from digestive vacuoles through the Plasmodium falciparum CQ resistance transporter (PfCRT) is essential to establish CQ resistance of the malaria parasite. However, the physiological relevance of PfCRT and how CQ-resistant PfCRT gains the ability to transport CQ remain unknown. We prepared proteoliposomes containing purified CQ-sensitive and CQ-resistant PfCRTs and measured their transport activities. All PfCRTs tested actively took up tetraethylammonium, verapamil, CQ, basic amino acids, polypeptides, and polyamines at the expense of an electrochemical proton gradient. CQ-resistant PfCRT exhibited decreased affinity for CQ, resulting in increased CQ uptake. Furthermore, CQ competitively inhibited amino acid transport. Thus, PfCRT is a H(+)-coupled polyspecific nutrient and drug exporter.
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167
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Pandey P, Singh S, Tewari N, Srinivas K, Shukla A, Gupta N, Vasudev PG, Khan F, Pal A, Bhakuni RS, Tandon S, Kumar JK, Banerjee S. Hairy root mediated functional derivatization of artemisinin and their bioactivity analysis. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.molcatb.2015.01.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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168
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Severini C, Menegon M. Resistance to antimalarial drugs: An endless world war against Plasmodium that we risk losing. J Glob Antimicrob Resist 2015; 3:58-63. [PMID: 27873670 DOI: 10.1016/j.jgar.2015.02.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 01/23/2015] [Accepted: 02/02/2015] [Indexed: 10/23/2022] Open
Abstract
The objective of this review was to describe the 'state of the art' of Plasmodium falciparum resistance to the main antimalarial drugs. A brief note on Plasmodium vivax is also included. Resistance of P. falciparum to the various antimalarials has a long history of hits and misses. During the last 60 years, the pace at which this parasite has developed resistance to antimalarial drugs has exceeded the pace at which new drugs have been developed. In the last decade, the introduction of artemisinin-based combination therapies (ACTs) as a first-line drug treatment for non-complicated P. falciparum malaria had led to extraordinary results in disease control, especially in sub-Saharan Africa. However, the emergence and spread of resistance to artemisinin in Southeast Asia jeopardise these results. In conclusion, the possible spread of artemisinin resistance in Africa should be considered as an epochal disaster.
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Affiliation(s)
- Carlo Severini
- Department of Infectious, Parasitic and Immune-mediated Diseases, Istituto Superiore di Sanità, Rome, Italy.
| | - Michela Menegon
- Department of Infectious, Parasitic and Immune-mediated Diseases, Istituto Superiore di Sanità, Rome, Italy
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169
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Hagenlocher M, Castro MC. Mapping malaria risk and vulnerability in the United Republic of Tanzania: a spatial explicit model. Popul Health Metr 2015; 13:2. [PMID: 25674040 PMCID: PMC4324856 DOI: 10.1186/s12963-015-0036-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 01/21/2015] [Indexed: 12/02/2022] Open
Abstract
Background Outbreaks of vector-borne diseases (VBDs) impose a heavy burden on vulnerable populations. Despite recent progress in eradication and control, malaria remains the most prevalent VBD. Integrative approaches that take into account environmental, socioeconomic, demographic, biological, cultural, and political factors contributing to malaria risk and vulnerability are needed to effectively reduce malaria burden. Although the focus on malaria risk has increasingly gained ground, little emphasis has been given to develop quantitative methods for assessing malaria risk including malaria vulnerability in a spatial explicit manner. Methods Building on a conceptual risk and vulnerability framework, we propose a spatial explicit approach for modeling relative levels of malaria risk - as a function of hazard, exposure, and vulnerability - in the United Republic of Tanzania. A logistic regression model was employed to identify a final set of risk factors and their contribution to malaria endemicity based on multidisciplinary geospatial information. We utilized a Geographic Information System for the construction and visualization of a malaria vulnerability index and its integration into a spatially explicit malaria risk map. Results The spatial pattern of malaria risk was very heterogeneous across the country. Malaria risk was higher in Mainland areas than in Zanzibar, which is a result of differences in both malaria entomological inoculation rate and prevailing vulnerabilities. Areas of high malaria risk were identified in the southeastern part of the country, as well as in two distinct “hotspots” in the northwestern part of the country bordering Lake Victoria, while concentrations of high malaria vulnerability seem to occur in the northwestern, western, and southeastern parts of the mainland. Results were visualized using both 10×10 km2 grids and subnational administrative units. Conclusions The presented approach makes an important contribution toward a decision support tool. By decomposing malaria risk into its components, the approach offers evidence on which factors could be targeted for reducing malaria risk and vulnerability to the disease. Ultimately, results offer relevant information for place-based intervention planning and more effective spatial allocation of resources. Electronic supplementary material The online version of this article (doi:10.1186/s12963-015-0036-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Michael Hagenlocher
- Interfaculty Department of Geoinformatics - Z_GIS, University of Salzburg, Schillerstr. 30, 5020 Salzburg, Austria
| | - Marcia C Castro
- Department of Global Health and Population, Harvard School of Public Health, 677 Huntington Avenue, Boston, MA 02115 USA
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170
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Mwande Maguene G, Lekana-Douki JB, Mouray E, Bousquet T, Grellier P, Pellegrini S, Toure Ndouo FS, Lebibi J, Pélinski L. Synthesis and in vitro antiplasmodial activity of ferrocenyl aminoquinoline derivatives. Eur J Med Chem 2015; 90:519-25. [DOI: 10.1016/j.ejmech.2014.11.065] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 10/30/2014] [Accepted: 11/30/2014] [Indexed: 11/26/2022]
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171
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Imported malaria in portugal 2000-2009: a role for hospital statistics for better estimates and surveillance. Malar Res Treat 2014; 2014:373029. [PMID: 25548715 PMCID: PMC4273509 DOI: 10.1155/2014/373029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 10/03/2014] [Accepted: 11/17/2014] [Indexed: 11/18/2022] Open
Abstract
Background. Although eradicated in Portugal, malaria keeps taking its toll on travelers and migrants from endemic countries. Disease notification is mandatory but is compromised by underreporting. Methods. A retrospective study on malaria hospitalizations for 10 consecutive years (2000–2009) was conducted. Data on hospitalizations and notifications were obtained from Central Administration of Health System and Health Protection Agency, respectively. For data selection ICD-9 CM and ICD-10 were used: codes 084*, 647.4, and B50–B54. Variables were gender, age, agent and origin of infection, length of stay (LOS), lethality, and comorbidities. Analysis included description, hypothesis testing, and regression. Results. There were 2003 malaria hospitalizations and 480 notified hospitalized cases, mainly in young male adults. P. falciparum was the main agent of infection acquired mainly in sub-Saharan Africa. Lethality was 1.95% and mean LOS was 8.09 days. Older age entailed longer LOS and increased lethality. Discussion. From 2000 to 2009, there were 2003 malaria hospitalizations with decreasing annual incidence, these numbers being remarkably higher than those notified. The national database of diagnosis related groups, reflecting hospitalizations on NHS hospitals, may be an unexplored complementary source for better estimates on imported malaria.
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172
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Kumar R, Sagar C, Sharma D, Kishor P. β-Globin Genes: Mutation Hot-Spots in the Global Thalassemia Belt. Hemoglobin 2014; 39:1-8. [DOI: 10.3109/03630269.2014.985831] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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173
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Therapeutic responses of Plasmodium vivax malaria to chloroquine and primaquine treatment in northeastern Myanmar. Antimicrob Agents Chemother 2014; 59:1230-5. [PMID: 25512415 DOI: 10.1128/aac.04270-14] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Chloroquine-primaquine (CQ-PQ) continues to be the frontline therapy for radical cure of Plasmodium vivax malaria. Emergence of CQ-resistant (CQR) P. vivax parasites requires a shift to artemisinin combination therapies (ACTs), which imposes a significant financial, logistical, and safety burden. Monitoring the therapeutic efficacy of CQ is thus important. Here, we evaluated the therapeutic efficacy of CQ-PQ for P. vivax malaria in northeast Myanmar. We recruited 587 patients with P. vivax monoinfection attending local malaria clinics during 2012 to 2013. These patients received three daily doses of CQ at a total dose of 24 mg of base/kg of body weight and an 8-day PQ treatment (0.375 mg/kg/day) commencing at the same time as the first CQ dose. Of the 401 patients who finished the 28-day follow-up, the cumulative incidence of recurrent parasitemia was 5.20% (95% confidence interval [CI], 3.04% to 7.36%). Among 361 (61%) patients finishing a 42-day follow-up, the cumulative incidence of recurrent blood-stage infection reached 7.98% (95% CI, 5.20% to 10.76%). The cumulative risk of gametocyte carriage at days 28 and 42 was 2.21% (95% CI, 0.78% to 3.64%) and 3.93% (95% CI, 1.94% to 5.92%), respectively. Interestingly, for all 15 patients with recurrent gametocytemia, this was associated with concurrent asexual stages. Genotyping of recurrent parasites at the merozoite surface protein 3α gene locus from 12 patients with recurrent parasitemia within 28 days revealed that 10 of these were the same genotype as at day 0, suggesting recrudescence or relapse. Similar studies in 70 patients in the same area in 2007 showed no recurrent parasitemias within 28 days. The sensitivity to chloroquine of P. vivax in northeastern Myanmar may be deteriorating.
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174
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Epis S, Porretta D, Mastrantonio V, Urbanelli S, Sassera D, De Marco L, Mereghetti V, Montagna M, Ricci I, Favia G, Bandi C. Temporal dynamics of the ABC transporter response to insecticide treatment: insights from the malaria vector Anopheles stephensi. Sci Rep 2014; 4:7435. [PMID: 25504146 PMCID: PMC4262823 DOI: 10.1038/srep07435] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 11/21/2014] [Indexed: 12/05/2022] Open
Abstract
In insects, ABC transporters have been shown to contribute to defence/resistance to insecticides by reducing toxic concentrations in cells/tissues. Despite the extensive studies about this detoxifying mechanism, the temporal patterns of ABC transporter activation have been poorly investigated. Using the malaria vector Anopheles stephensi as a study system, we investigated the expression profile of ABC genes belonging to different subfamilies in permethrin-treated larvae at different time points (30 min to 48 h). Our results showed that the expression of ABCB and ABCG subfamily genes was upregulated at 1 h after treatment, with the highest expression observed at 6 h. Therefore, future investigations on the temporal dynamics of ABC gene expression will allow a better implementation of insecticide treatment regimens, including the use of specific inhibitors of ABC efflux pumps.
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Affiliation(s)
- Sara Epis
- Department of Veterinary Science and Public Health, University of Milan, Milan, Italy
| | - Daniele Porretta
- Department of Environmental Biology, University "La Sapienza" of Rome, Rome, Italy
| | | | - Sandra Urbanelli
- Department of Environmental Biology, University "La Sapienza" of Rome, Rome, Italy
| | - Davide Sassera
- Department of Biology and Biotechnology, University of Pavia, Pavia, Italy
| | - Leone De Marco
- Department of Biology and Biotechnology, University of Pavia, Pavia, Italy
| | - Valeria Mereghetti
- Department of Veterinary Science and Public Health, University of Milan, Milan, Italy
| | - Matteo Montagna
- Department of Agricultural and Environmental Sciences, University of Milan, Milan, Italy
| | - Irene Ricci
- School of Bioscience and Veterinary Medicine, University of Camerino, Camerino, Italy
| | - Guido Favia
- School of Bioscience and Veterinary Medicine, University of Camerino, Camerino, Italy
| | - Claudio Bandi
- Department of Veterinary Science and Public Health, University of Milan, Milan, Italy
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175
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Nixon CP, Nixon CE, Arsyad DS, Chand K, Yudhaputri FA, Sumarto W, Wangsamuda S, Asih PB, Marantina SS, Wahid I, Han G, Friedman JF, Bangs MJ, Syafruddin D, Baird JK. Distance to Anopheles sundaicus larval habitats dominant among risk factors for parasitemia in meso-endemic Southwest Sumba, Indonesia. Pathog Glob Health 2014; 108:369-80. [PMID: 25495283 DOI: 10.1179/2047773214y.0000000167] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
BACKGROUND The decline in intensity of malaria transmission in many areas now emphasizes greater importance of understanding the epidemiology of low to moderate transmission settings. Marked heterogeneity in infection risk within these populations creates opportunities to understand transmission and guide resource allocation to greater impact. METHODS In this study, we examined spatial patterns of malaria transmission in a hypo- to meso-endemic area of eastern Indonesia using malaria prevalence data collected from a cross-sectional socio-demographic and parasitological survey conducted from August to November 2010. An entomological survey performed in parallel, identified, mapped, and monitored local anopheline larval habitats. RESULTS A single spatial cluster of higher malaria prevalence was detected during the study period (relative risk=2.13; log likelihood ratio=20.7; P<0.001). In hierarchical multivariate regression models, risk of parasitemia was inversely correlated with distance to five Anopheles sundaicus known larval habitats [odds ratio (OR)=0.21; 95% confidence interval (CI)=0.14-0.32; P<0.001], which were located in a geographically restricted band adjacent to the coastline. Increasing distance from these sites predicted increased hemoglobin level across age strata after adjusting for confounders (OR=1.6; 95% CI=1.30-1.98; P<0.001). CONCLUSION Significant clustering of malaria parasitemia in close proximity to very specific and relatively few An. sundaicus larval habitats has direct implications for local control strategy, policy, and practice. These findings suggest that larval source management could achieve profound if not complete impact in this region.
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Confirmation of a founder effect in a Northern European population of a new β-globin variant: HBB:c.23_26dup (codons 8/9 (+AGAA)). Eur J Hum Genet 2014; 23:1158-64. [PMID: 25469539 PMCID: PMC4538212 DOI: 10.1038/ejhg.2014.263] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 10/27/2014] [Accepted: 10/30/2014] [Indexed: 11/25/2022] Open
Abstract
β-Thalassemia is a genetic disease caused by a defect in the production of the β-like globin chain. More than 200 known different variants can lead to the disease and are mainly found in populations that have been exposed to malaria parasites. We recently described a duplication of four nucleotides in the first exon of β-globin gene in several families of patients living in Nord-Pas-de-Calais (France). Using the genotypes at 12 microsatellite markers surrounding the β-globin gene of four unrelated variant carriers plus an additional one recently discovered, we found that they shared a common haplotype indicating a founder effect that was estimated to have taken place 225 years ago (nine generations). In order to determine whether this variant arose in this region of Northern Europe or was introduced by migrants from regions of the world where thalassemia is endemic, we genotyped the first 4 unrelated variant carriers and 32 controls from Nord-Pas-de-Calais for 97 European ancestry informative markers (EAIMs). Using these EAIMs and comparing with population reference panels, we demonstrated that the variant carriers were very similar to the controls and were closer to North European populations than to South European or Middle-East populations. Rare β-thalassemia variants have already been described in patients sampled in non-endemic regions, but it is the first proof of a founder effect in Northern Europe.
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177
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Mohamad D, Suppian R, Mohd Nor N. Immunomodulatory effects of recombinant BCG expressing MSP-1C of Plasmodium falciparum on LPS- or LPS+IFN-γ-stimulated J774A.1 cells. Hum Vaccin Immunother 2014; 10:1880-6. [PMID: 25424796 DOI: 10.4161/hv.28695] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Macrophage phagocytosis is the first line of defense of the innate immune system against malaria parasite infection. This study evaluated the immunomodulatory effects of BCG and recombinant BCG (rBCG) strains expressing the C-terminus of the merozoite surface protein-1 (MSP-1C) of Plasmodium falciparum on mouse macrophage cell line J774A.1 in the presence or absence of lipopolysaccharide (LPS) or LPS + IFN-γ. The rBCG strain significantly enhanced phagocytic activity, production of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, nitric oxide (NO), and inducible nitric oxide synthase (iNOS) as compared with parental BCG strain, and these activities increased in the presence of LPS and LPS+IFN-γ. Furthermore, the rBCG strain also significantly reduced the macrophage viability as well as the rBCG growth suggesting the involvement of macrophage apoptosis. Taken together, these data indicate that the rBCG strain has an immunomodulatory effect on macrophages, thus strengthen the rational use of rBCG to control malaria infection.
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Affiliation(s)
- Dhaniah Mohamad
- a School of Health Sciences; Health Campus; Universiti Sains Malaysia; Kelantan, Malaysia
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178
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Duru KC, Thomas BN. Genetic Diversity and Allelic Frequency of Glutamate-Rich Protein (GLURP) in Plasmodium falciparum Isolates from Sub-Saharan Africa. Microbiol Insights 2014; 7:35-9. [PMID: 25452699 PMCID: PMC4240185 DOI: 10.4137/mbi.s20618] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 10/21/2014] [Accepted: 10/24/2014] [Indexed: 11/05/2022] Open
Abstract
Glutamate-rich protein is a Plasmodium falciparum (Pf) antigen found in all stages of the parasite and has been reported to induce clinical immunity. The R0 and R2 regions have been found to exhibit a high degree of conservation, therefore serving as a good vaccine design material. We assayed the genetic diversity of Pf glurp genes in the R0 and R2 regions, as well as evaluated the role of seasonality on allelic frequency. A total of 402 genomic DNA samples, extracted from filter paper blood samples, were screened by nested polymerase chain reaction (PCR) analysis of Pf glurp R0 and R2 regions, in addition to fragment analysis of the polymorphic regions to identify allelic diversity of the parasite population. We found an extensive heterogeneity in the R2 region in general, and this heterogeneity is seasonally dependent, indicative of region plasticity. The R0 region displayed genetic conservation, as expected. We conclude that positive genotyping results with glurp R0 region should be seen as indicative of an active Pf infection, requiring adequate treatment. In addition, we advocate extending the possibility that an R0 region genotypic positivity could serve as diagnostic tool, thereby reducing cases of untreated or poorly treated infection, contributory to recrudescence or treatment failure.
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Affiliation(s)
- Kimberley C Duru
- Department of Biomedical Sciences, Rochester Institute of Technology, Rochester, NY, USA
| | - Bolaji N Thomas
- Department of Biomedical Sciences, Rochester Institute of Technology, Rochester, NY, USA
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179
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Role of Different Pfcrt and Pfmdr-1 Mutations in Conferring Resistance to Antimalaria Drugs in Plasmodium falciparum. Malar Res Treat 2014; 2014:950424. [PMID: 25506039 PMCID: PMC4243603 DOI: 10.1155/2014/950424] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2014] [Accepted: 08/30/2014] [Indexed: 01/28/2023] Open
Abstract
Emergence of drugs resistant strains of Plasmodium falciparum has augmented the scourge of malaria in endemic areas. Antimalaria drugs act on different intracellular targets. The majority of them interfere with digestive vacuoles (DVs) while others affect other organelles, namely, apicoplast and mitochondria. Prevention of drug accumulation or access into the target site is one of the mechanisms that plasmodium adopts to develop resistance. Plasmodia are endowed with series of transporters that shuffle drugs away from the target site, namely, pfmdr (Plasmodium falciparum multidrug resistance transporter) and pfcrt (Plasmodium falciparum chloroquine resistance transporter) which exist in DV membrane and are considered as putative markers of CQ resistance. They are homologues to human P-glycoproteins (P-gh or multidrug resistance system) and members of drug metabolite transporter (DMT) family, respectively. The former mediates drifting of xenobiotics towards the DV while the latter chucks them outside. Resistance to drugs whose target site of action is intravacuolar develops when the transporters expel them outside the DVs and vice versa for those whose target is extravacuolar. In this review, we are going to summarize the possible pfcrt and pfmdr mutation and their role in changing plasmodium sensitivity to different anti-Plasmodium drugs.
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180
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Kosuwin R, Putaporntip C, Tachibana H, Jongwutiwes S. Spatial variation in genetic diversity and natural selection on the thrombospondin-related adhesive protein locus of Plasmodium vivax (PvTRAP). PLoS One 2014; 9:e110463. [PMID: 25333779 PMCID: PMC4204863 DOI: 10.1371/journal.pone.0110463] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Accepted: 09/04/2014] [Indexed: 11/18/2022] Open
Abstract
Thrombospondin-related adhesive protein (TRAP) of malaria parasites is essential for sporozoite motility and invasions into mosquito’s salivary gland and vertebrate’s hepatocyte; thereby, it is a promising target for pre-erythrocytic vaccine. TRAP of Plasmodium vivax (PvTRAP) exhibits sequence heterogeneity among isolates, an issue relevant to vaccine development. To gain insights into variation in the complete PvTRAP sequences of parasites in Thailand, 114 vivax malaria patients were recruited in 2006–2007 from 4 major endemic provinces bordering Myanmar (Tak in the northwest, n = 30 and Prachuap Khirikhan in the southwest, n = 25), Cambodia (Chanthaburi in the east, n = 29) and Malaysia (Yala and Narathiwat in the south, n = 30). In total, 26 amino acid substitutions were detected and 9 of which were novel, resulting in 44 distinct haplotypes. Haplotype and nucleotide diversities were lowest in southern P. vivax population while higher levels of diversities were observed in other populations. Evidences of positive selection on PvTRAP were demonstrated in domains II and IV and purifying selection in domains I, II and VI. Genetic differentiation was significant between each population except that between populations bordering Myanmar where transmigration was common. Regression analysis of pairwise linearized Fst and geographic distance suggests that P. vivax populations in Thailand have been isolated by distance. Sequence diversity of PvTRAP seems to be temporally stable over one decade in Tak province based on comparison of isolates collected in 1996 (n = 36) and 2006–2007. Besides natural selection, evidences of intragenic recombination have been supported in this study that could maintain and further generate diversity in this locus. It remains to be investigated whether amino acid substitutions in PvTRAP could influence host immune responses although several predicted variant T cell epitopes drastically altered the epitope scores. Knowledge on geographic diversity in PvTRAP constitutes an important basis for vaccine design provided that vaccination largely confers variant-specific immunity.
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Affiliation(s)
- Rattiporn Kosuwin
- Molecular Biology of Malaria and Opportunistic Parasites Research Unit, Department of Parasitology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Chaturong Putaporntip
- Molecular Biology of Malaria and Opportunistic Parasites Research Unit, Department of Parasitology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Hiroshi Tachibana
- Department of Infectious Diseases, Tokai University School of Medicine, Kanagawa, Japan
| | - Somchai Jongwutiwes
- Molecular Biology of Malaria and Opportunistic Parasites Research Unit, Department of Parasitology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
- * E-mail:
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O’Brien AT, Ramírez JF, Martínez SP. A descriptive study of 16 severe Plasmodium vivax cases from three municipalities of Colombia between 2009 and 2013. Malar J 2014; 13:404. [PMID: 25318617 PMCID: PMC4203896 DOI: 10.1186/1475-2875-13-404] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Accepted: 10/10/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Plasmodium vivax, the most geographically distributed cause of malaria, accounts for more than 70% of cases in the Americas. In Colombia, P. vivax was responsible for 67.3% of cases in the last five years. Despite vivax malaria impact worldwide, historically it has been neglected and considered to be a benign disease. In the last decade medical literature reports have emerged countering this benign outlook. This study pretends to describe the clinical and paraclinical profile of severe vivax malaria cases hospitalized in Tumaco, Cali, Buenaventura between 2009 and 2013, to contribute to the knowledge regarding the behaviour and clinical expression of this disease. METHODS This is a descriptive, retrospective case-series study of 16 severe malaria vivax cases, hospitalized between 2009 and 2013, in Colombian municipalities of Tumaco, Buenaventura and Cali. Severe malaria vivax cases were defined using criteria adapted from the national guidelines. Descriptive analyses of reason for consultation, signs and symptoms, diagnosis, treatment, paraclinical characteristics, complications, and time hospitalized, were conducted. RESULTS Sixteen cases of severe P. vivax were analysed. Fever, chills and headache were shown to be the main admission symptoms. Elevation of total bilirubin levels in 18.75%, and severe thrombocytopaenia in 25% of cases were the main complications presented during hospitalization. All cases responded to treatment, there were no deaths. CONCLUSIONS The following questions derived from this study could be the basis for future research: 1) Does the time to consultation have an impact on the number of days hospitalized and how cases progress during hospitalization, 2) Are the severity criteria in WHO guidelines sensitive enough to be used in clinical practice compared to national guidelines, and 3) How does malnutrition contribute to anaemia in malaria-endemic regions.
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Affiliation(s)
- Anthony T O’Brien
- Fundación Santa Fe de Bogotá Centro de Estudios e Investigación en Salud - CEI, Carrera 7 B # 123-90, Piso 3, Bogotá, Colombia
| | - Jesica F Ramírez
- Fundación Santa Fe de Bogotá Centro de Estudios e Investigación en Salud - CEI, Carrera 7 B # 123-90, Piso 3, Bogotá, Colombia
| | - Sandra P Martínez
- Fundación Santa Fe de Bogotá Centro de Estudios e Investigación en Salud - CEI, Carrera 7 B # 123-90, Piso 3, Bogotá, Colombia
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182
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Immunological Testing Reveals Exposure to Malaria in the Hypoendemic Region of Iran. INTERNATIONAL SCHOLARLY RESEARCH NOTICES 2014; 2014:614287. [PMID: 27379331 PMCID: PMC4897229 DOI: 10.1155/2014/614287] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Revised: 07/02/2014] [Accepted: 07/07/2014] [Indexed: 11/25/2022]
Abstract
Background. South eastern parts of Iran remain endemic for malaria infection. There is some concern that malaria infection may spread into Bushehr, which is located in the south western part bordering the Persian Gulf and at the periphery of the declared endemic region Hormozgan province due to frequency of visitors from eastern endemic areas and from neighboring malaria endemic countries. We investigated malaria prevalence in Bushehr. Methods and Results. Attempts were made to identify malaria active infection in blood smears and malaria specific antibody and antigens in serum samples. Traditional blood smears prepared from 1955 blood specimens yielded no definitive malaria positive case by microscopic technique. A total of 270 (13.8%) serum samples were positive for malaria antibodies. Using specific ELISA kits, presence of histidine rich proteins and lactate dehydrogenase antigens were investigated in serum samples. No histidine rich proteins specific for P. falciparum were detected amongst 270 antibody positive samples. However, six samples representing 0.3% of total population, were found to be positive for plasmodium pan specific lactate dehydrogenase antigens. This suggested the possibility of low level exposure to malaria in Bushehr community. Conclusions. Out of a total of 1955 samples tested, 270 (13.8%) were positive for malaria antibodies and six (0.3%) of these were positive for plasmodium-specific lactate dehydrogenase antigen suggesting a low level exposure to malaria in a hypoendemic region based on immunological testing. Since none of the 270 antibody samples were positive for histidine rich protein antigens, there is scope for further testing of blood samples by molecular methods such as polymerase chain reactions to confirm the plasmodium species and provide information valuable for future investigations. Our testing strategy for hypoemdemic malaria can be used as a template for investing malaria in 32 eliminating countries for testing ongoing transmission. This approach may be useful as a method in epidemiological studies.
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183
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Coleman M, Al-Zahrani MH, Coleman M, Hemingway J, Omar A, Stanton MC, Thomsen EK, Alsheikh AA, Alhakeem RF, McCall PJ, Rabeeah AAA, Memish ZA. A country on the verge of malaria elimination--the Kingdom of Saudi Arabia. PLoS One 2014; 9:e105980. [PMID: 25250619 PMCID: PMC4175080 DOI: 10.1371/journal.pone.0105980] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2014] [Accepted: 07/28/2014] [Indexed: 11/29/2022] Open
Abstract
Significant headway has been made in the global fight against malaria in the past decade and as more countries enter the elimination phase, attention is now focused on identifying effective strategies to shrink the malaria map. Saudi Arabia experienced an outbreak of malaria in 1998, but is now on the brink of malaria elimination, with just 82 autochthonous cases reported in 2012. A review of published and grey literature was performed to identify the control strategies that have contributed to this achievement. The number of autochthonous malaria cases in Saudi Arabia decreased by 99.8% between 1998 and 2012. The initial steep decline in malaria cases coincided with a rapid scaling up of vector control measures. Incidence continued to be reported at low levels (between 0.01 and 0.1 per 1,000 of the population) until the adoption of artesunate plus sulfadoxine-pyrimethamine as first line treatment and the establishment of a regional partnership for a malaria-free Arabian Peninsula, both of which occurred in 2007. Since 2007, incidence has decreased by nearly an order of magnitude. Malaria incidence is now very low, but a high proportion of imported cases, continued potential for autochthonous transmission, and an increased proportion of cases attributable to Plasmodium vivax all present challenges to Saudi Arabia as they work toward elimination by 2015.
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Affiliation(s)
- Michael Coleman
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- * E-mail:
| | | | - Marlize Coleman
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Janet Hemingway
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Abdiasiis Omar
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Michelle C. Stanton
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Eddie K. Thomsen
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Adel A. Alsheikh
- Public Health Directorate, Ministry of Health, Riyadh, Kingdom of Saudi Arabia
| | - Raafat F. Alhakeem
- Public Health Directorate, Ministry of Health, Riyadh, Kingdom of Saudi Arabia
| | - Phillip J. McCall
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Abdullah A. Al Rabeeah
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Public Health Directorate, Ministry of Health, Riyadh, Kingdom of Saudi Arabia
| | - Ziad A. Memish
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Public Health Directorate, Ministry of Health, Riyadh, Kingdom of Saudi Arabia
- College of Medicine, Alfaisal University, Riyadh, Kingdom of Saudi Arabia
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184
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Das LK, Padhi B, Sahu SS. Prediction of outcome of severe falciparum malaria in Koraput, Odisha, India: A hospital-based study. Trop Parasitol 2014; 4:105-10. [PMID: 25250231 PMCID: PMC4166794 DOI: 10.4103/2229-5070.138538] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 08/12/2014] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND AND OBJECTIVES Infection with Plasmodium falciparum, caused 627,000 deaths in 2012 in the world. P. falciparum infection causes myriads of clinical manifestations. Exact clinical manifestation resulting in poor prognosis in hyper-endemic epidemiological settings need to be ascertained to save human lives. A hospital-based study was conducted to elucidate the different severe clinical presentations of falciparum malaria and to examine the critical clinical and laboratory parameters on the prognosis of these severe manifestations in a stable hyper-endemic falciparum area in the state of Odisha, India. MATERIALS AND METHODS Consecutive patients admitted in a tertiary care hospital with severe manifestations of malaria as per WHO criteria and confirmed by parasitological examination were included in the study. A detailed clinical and biochemical parameters were examined. Clinical data were reviewed before being double entered into a computer and analyzed. Statistical analyses were carried out using Epi Info 6.04. Continuous and normal distributed data were compared by two-tailed Student's t-test and proportions compared with χ(2) tests with Yates' correction or Fisher's exact test. RESULTS AND DISCUSSION A total of 1320 patients with clinical malaria, diagnosed at outpatients' department were admitted in the hospital during the 1 year study period of which, 292 (22.1%) were children under 14 years of age. The major clinical categories on admission were hyperpyrexia (70.7%), cerebral malaria (9.4%), malarial anemia (7.7%), algid malaria (1.5%), and malaria associated categories were respiratory infection (2.2%), hepatitis (2.0%), urinary tract infection (1.8%), enteric fever (3.3%), and sickle cell disease (1.2%). The overall case fatality rate (CFR) was 4.3 (57/1320). The CFR in children 12.3 (36/292) was significantly higher when compared to adults, that is, 2.0 (21/1028). The major causes of death were cerebral malaria (45.6%), malaria along with a respiratory infection (19.3%) and anemia (10.5%). Malarial anemia along sickle cell disease accounted for 19.3% of all malaria related deaths. Proportion of mortality due to acute renal failure was higher in adults. Biochemical parameters suggest involvement of multiple organs. The findings suggest that the area can be effectively managed by sustained and continuous preventive and curative efforts.
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Affiliation(s)
- Lalit Kumar Das
- Unit of Clinical Epidemiology and Chemotherapy, Vector Control Research Centre (Indian Council of Medical Research), Medical Complex, Indira Nagar, Puducherry, India
| | - Bishwanath Padhi
- Department of Internal Medicine, District Headquarters Hospital, Koraput, Odisha, India
| | - Sudhansu Sekar Sahu
- Unit of Clinical Epidemiology and Chemotherapy, Vector Control Research Centre (Indian Council of Medical Research), Medical Complex, Indira Nagar, Puducherry, India
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185
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Ren X, Hughes GL, Niu G, Suzuki Y, Rasgon JL. Anopheles gambiae densovirus (AgDNV) has negligible effects on adult survival and transcriptome of its mosquito host. PeerJ 2014; 2:e584. [PMID: 25279264 PMCID: PMC4179393 DOI: 10.7717/peerj.584] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 08/28/2014] [Indexed: 02/03/2023] Open
Abstract
Mosquito densoviruses (DNVs) are candidate agents for paratransgenic control of malaria and other vector-borne diseases. Unlike other mosquito DNVs, the Anopheles gambiae DNV (AgDNV) is non-pathogenic to larval mosquitoes. However, the cost of infection upon adults and the molecular mechanisms underpinning infection in the mosquito host are unknown. Using life table analysis, we show that AgDNV infection has minimal effects on An. gambiae survival (no significant effect in 2 replicates and a slight 2 day survival decrease in the third replicate). Using microarrays, we show that AgDNV has very minimal effect on the adult mosquito transcriptome, with only 4-15 genes differentially regulated depending on the statistical criteria imposed. The minimal impact upon global transcription provides some mechanistic understanding of lack of virus pathogenicity, suggesting a long co-evolutionary history that has shifted towards avirulence. From an applied standpoint, lack of strong induced fitness costs makes AgDNV an attractive agent for paratransgenic malaria control.
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Affiliation(s)
- Xiaoxia Ren
- Pharmaceutics International Inc., Hunt Valley, MD, USA
| | - Grant L Hughes
- The Department of Entomology, Center for Infectious Disease Dynamics, and the Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, USA
| | - Guodong Niu
- The Department of Entomology, Center for Infectious Disease Dynamics, and the Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, USA
| | - Yasutsugu Suzuki
- The Department of Entomology, Center for Infectious Disease Dynamics, and the Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, USA
| | - Jason L Rasgon
- The Department of Entomology, Center for Infectious Disease Dynamics, and the Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, USA
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186
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Tchicaya AF, Wognin SB, Aka I, Kouassi YM, Guiza J, Bonny JS. Impacts professionnels et économiques du paludisme à Plasmodium falciparum sur une entreprise du secteur privé en Côte d’Ivoire. ARCH MAL PROF ENVIRO 2014. [DOI: 10.1016/j.admp.2014.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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187
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Transcriptome responses involved in artemisinin production in Artemisia annua L. under UV-B radiation. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2014; 140:292-300. [PMID: 25194528 DOI: 10.1016/j.jphotobiol.2014.08.013] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 08/01/2014] [Accepted: 08/05/2014] [Indexed: 11/23/2022]
Abstract
Artemisinin, an endoperoxide sesquiterpene lactone, is an effective antimalarial drug isolated from Artemisia annua L. In this study, a low dose (1.44 kJm(-2)d(-1)) of UV-B radiation (280-320 nm) for short-term (1h per day for 10 days) was applied to A. annua seedlings to stimulate artemisinin production. UV-B treatment not only induced the generation of reactive oxygen species (ROS), enhanced peroxidase activity and endogenous content of abscisic acid (ABA), but stimulated the biosynthesis of artemisinin in the seedlings. Here, transcriptomic changes during UV-B radiation in A. annua were detected using an Agilent GeneChip with 43,692 probe sets. In total, 358 transcripts were identified as differentially expressed under UV-B stress, of which 172 transcripts increased and 186 transcripts decreased in abundance. In terms of biological processes, gene ontology (GO) terms including primary carbohydrate and nitrogen compound metabolic processes were enriched in UV-B-repressed genes. The up-regulated genes were enriched in response to stress, ROS generation, hormone (ethylene, ABA) stimulus and cell cycle control. The expression of key enzymes such as amorpha-4,11-diene synthase (ADS) and cytochrome P450 dependent monooxygenase/hydroxylase (CYP71AV1), and related WRKY transcription factors was up-regulated significantly for artemisinin biosynthesis. This profile of global gene expression patterns during UV-B stress will be valuable for further identification of the enzymes involved in artemisinin biosynthesis.
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188
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Zou B, Nagle A, Chatterjee AK, Leong SY, Tan LJ, Sim WLS, Mishra P, Guntapalli P, Tully DC, Lakshminarayana SB, Lim CS, Tan YC, Abas SN, Bodenreider C, Kuhen KL, Gagaring K, Borboa R, Chang J, Li C, Hollenbeck T, Tuntland T, Zeeman AM, Kocken CHM, McNamara C, Kato N, Winzeler EA, Yeung BKS, Diagana TT, Smith PW, Roland J. Lead optimization of imidazopyrazines: a new class of antimalarial with activity on Plasmodium liver stages. ACS Med Chem Lett 2014; 5:947-50. [PMID: 25147620 DOI: 10.1021/ml500244m] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 07/06/2014] [Indexed: 02/02/2023] Open
Abstract
Imidazopyridine 1 was identified from a phenotypic screen against P. falciparum (Pf) blood stages and subsequently optimized for activity on liver-stage schizonts of the rodent parasite P. yoelii (Py) as well as hypnozoites of the simian parasite P. cynomolgi (Pc). We applied these various assays to the cell-based lead optimization of the imidazopyrazines, exemplified by 3 (KAI407), and show that optimized compounds within the series with improved pharmacokinetic properties achieve causal prophylactic activity in vivo and may have the potential to target the dormant stages of P. vivax malaria.
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Affiliation(s)
- Bin Zou
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, 138670 Singapore
| | - Advait Nagle
- Genomics Institute of the Novartis Research Foundation, San Diego, California 92121, United States
| | - Arnab K. Chatterjee
- Genomics Institute of the Novartis Research Foundation, San Diego, California 92121, United States
| | - Seh Yong Leong
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, 138670 Singapore
| | - Liying Jocelyn Tan
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, 138670 Singapore
| | - Wei Lin Sandra Sim
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, 138670 Singapore
| | - Pranab Mishra
- Genomics Institute of the Novartis Research Foundation, San Diego, California 92121, United States
| | - Prasuna Guntapalli
- Genomics Institute of the Novartis Research Foundation, San Diego, California 92121, United States
| | - David C. Tully
- Genomics Institute of the Novartis Research Foundation, San Diego, California 92121, United States
| | | | - Chek Shik Lim
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, 138670 Singapore
| | - Yong Cheng Tan
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, 138670 Singapore
| | - Siti Nurdiana Abas
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, 138670 Singapore
| | - Christophe Bodenreider
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, 138670 Singapore
| | - Kelli L. Kuhen
- Genomics Institute of the Novartis Research Foundation, San Diego, California 92121, United States
| | - Kerstin Gagaring
- Genomics Institute of the Novartis Research Foundation, San Diego, California 92121, United States
| | - Rachel Borboa
- Genomics Institute of the Novartis Research Foundation, San Diego, California 92121, United States
| | - Jonathan Chang
- Genomics Institute of the Novartis Research Foundation, San Diego, California 92121, United States
| | - Chun Li
- Genomics Institute of the Novartis Research Foundation, San Diego, California 92121, United States
| | - Thomas Hollenbeck
- Genomics Institute of the Novartis Research Foundation, San Diego, California 92121, United States
| | - Tove Tuntland
- Genomics Institute of the Novartis Research Foundation, San Diego, California 92121, United States
| | - Anne-Marie Zeeman
- Department of Parasitology, Biomedical Primate Research Centre, 2280 GH Rijswijk, The Netherlands
| | - Clemens H. M. Kocken
- Department of Parasitology, Biomedical Primate Research Centre, 2280 GH Rijswijk, The Netherlands
| | - Case McNamara
- Genomics Institute of the Novartis Research Foundation, San Diego, California 92121, United States
| | - Nobutaka Kato
- Genomics Institute of the Novartis Research Foundation, San Diego, California 92121, United States
| | - Elizabeth A. Winzeler
- Genomics Institute of the Novartis Research Foundation, San Diego, California 92121, United States
- Department of Pediatrics, School of Medicine, University of California, San Diego, California 92093, United States
| | - Bryan K. S. Yeung
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, 138670 Singapore
| | - Thierry T. Diagana
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, 138670 Singapore
| | - Paul W. Smith
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, 138670 Singapore
| | - Jason Roland
- Genomics Institute of the Novartis Research Foundation, San Diego, California 92121, United States
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189
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Lauderdale JM, Caminade C, Heath AE, Jones AE, MacLeod DA, Gouda KC, Murty US, Goswami P, Mutheneni SR, Morse AP. Towards seasonal forecasting of malaria in India. Malar J 2014; 13:310. [PMID: 25108445 PMCID: PMC4251696 DOI: 10.1186/1475-2875-13-310] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2014] [Accepted: 08/03/2014] [Indexed: 11/10/2022] Open
Abstract
Background Malaria presents public health challenge despite extensive intervention campaigns. A 30-year hindcast of the climatic suitability for malaria transmission in India is presented, using meteorological variables from a state of the art seasonal forecast model to drive a process-based, dynamic disease model. Methods The spatial distribution and seasonal cycles of temperature and precipitation from the forecast model are compared to three observationally-based meteorological datasets. These time series are then used to drive the disease model, producing a simulated forecast of malaria and three synthetic malaria time series that are qualitatively compared to contemporary and pre-intervention malaria estimates. The area under the Relative Operator Characteristic (ROC) curve is calculated as a quantitative metric of forecast skill, comparing the forecast to the meteorologically-driven synthetic malaria time series. Results and discussion The forecast shows probabilistic skill in predicting the spatial distribution of Plasmodium falciparum incidence when compared to the simulated meteorologically-driven malaria time series, particularly where modelled incidence shows high seasonal and interannual variability such as in Orissa, West Bengal, and Jharkhand (North-east India), and Gujarat, Rajastan, Madhya Pradesh and Maharashtra (North-west India). Focusing on these two regions, the malaria forecast is able to distinguish between years of “high”, “above average” and “low” malaria incidence in the peak malaria transmission seasons, with more than 70% sensitivity and a statistically significant area under the ROC curve. These results are encouraging given that the three month forecast lead time used is well in excess of the target for early warning systems adopted by the World Health Organization. This approach could form the basis of an operational system to identify the probability of regional malaria epidemics, allowing advanced and targeted allocation of resources for combatting malaria in India.
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Affiliation(s)
- Jonathan M Lauderdale
- Department of Earth, Atmospheric and Planetary Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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190
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Smith C, Whittaker M. Beyond mobile populations: a critical review of the literature on malaria and population mobility and suggestions for future directions. Malar J 2014; 13:307. [PMID: 25106437 PMCID: PMC4249613 DOI: 10.1186/1475-2875-13-307] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 07/28/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Although population mobility is frequently cited as a barrier to malaria elimination, a comparatively small body of literature has attempted to systematically examine this issue. This article reviews the literature on malaria and mobile populations in order to critically examine the ways that malaria elimination experts perceive the risks surrounding population mobility. The article brings in perspectives from HIV/AIDS and other infectious disease control programmes working in areas of high population mobility. The article aims to move beyond the current tendency to identify mobile populations as a risk group and suggests ways to reconceptualize and respond to population mobility within malaria elimination. METHODS The review was commissioned by the Asia Pacific Malaria Elimination Network (APMEN). Searches were made using PubMed, ProQuest, Google and Google Scholar. The review includes English language published peer-reviewed literature and grey literature published up to November 2013. RESULTS The review identified three key themes in the literature: mobility, economic development and shifting land use; concerns about accessing mobile populations; and imported and border malaria. The review found that the literature treats mobile populations as a homogenous entity and is yet to develop a more accurate understanding of the true risks surrounding population mobility. Concerns about accessing mobile populations are overstated, and methods are suggested for working collaboratively with mobile populations. Finally, the review found that many concerns about mobile populations and imported malaria would be more productively framed as border health issues. CONCLUSION The focus on mobile populations is both excessive and insufficiently examined within the current literature. By its very nature, population mobility requires malaria elimination programmes to look beyond isolated localities and demographic groups to respond to the interconnections that mobility creates between localities and population groups. Malaria programmes will gain greater clarity by refocusing the discussion away from mobile populations as a risk group and toward mobility as a system involving interconnected localities and multiple demographic groups. Rather than focusing on mobile populations as a risk group and a barrier to elimination, malaria elimination programmes ought to develop collaborative community engagement efforts in border areas and regions of high population mobility and where imported malaria is of concern.
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Affiliation(s)
- Catherine Smith
- School of Population Health, Herston Campus, University of Queensland, Brisbane, Qld 4006, Australia.
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191
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Omotuyi OI. Methyl-methoxylpyrrolinone and flavinium nucleus binding signatures on falcipain-2 active site. J Mol Model 2014; 20:2386. [PMID: 25096811 DOI: 10.1007/s00894-014-2386-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 07/17/2014] [Indexed: 01/18/2023]
Abstract
Following the increasing reports of human toxicity and plasmodium resistance to artemisinin and its derivatives, falcipain-2 (FP-2) is now emerging as the choice antimalarial drug target. Coincidentally, FP-2 is the in vivo target of naturally occurring, therapeutically safe flavonoids (stenopalustroside, myricetin, and fisetin) and symplostatin (symplostatin 4) compounds known to exhibit potent in vitro and in vivo antiplasmodial actions. Here, the structural bases for their inhibitory actions have been studied using molecular dynamics simulation. Myricetin and fisetin act as proton transfer tunnel breakers by inserting between His174 and Cys42, which are key active site residues of FP-2, stenopalustroside inhibits the polarization of His174 by Asn173; a major preparatory step for Cys42/His174 proton transfer process. The roles of flavonoids are favored by T-shaped pi-pi interactions with His174. Symplostatin 4 inserts its methyl-methoxylpyrrolinone moiety into the active site where its proton acceptor function prepares Cys42 for nucleophilic attack on the Michael α,β-unsaturated bonds on its 4(S)-amino-2(E)-pentenoate moiety. Further analyses of the structures identified a unique bridge formed on FP-2 active site groove by stenopalustroside and symplostatin 4 during interaction with the sub-site I of FP-2, whereas fisetin preferentially interacts with sub-site II and myricetin interacts with sub-site III residues. Ultimately, symplostatin-4, myricetin, and fisetin were better than stenopalustroside at trapping FP-2 in its inactive state as revealed by comparative RSMD plots with X-ray structures of FP-2 co-crystallized with inhibitors. Comparative estimates of free energy of binding using the Molecular Mechanics-Poisson Boltzmann Surface Area (MMPBSA) method suggested that His174 protonation may further enhance stenopalustroside-FP-2 interaction. The unique binding signatures of the ligands within the FP-2 active site groove and its sub-sites may explain the subtle differences in their IC50 values and their mechanism of inhibition.
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Affiliation(s)
- Olaposi I Omotuyi
- Center for Drug Discovery and Therapeutic Innovation, Nagasaki University, Nagasaki, Japan,
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192
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Siqueira AM, Cavalcante JA, Vítor-Silva S, Reyes-Lecca RC, Alencar AC, Monteiro WM, Alexandre MAA, Maria Paula G M, Guinovart C, Bassat Q, Alecrim MDGC, Lacerda MVG. Influence of age on the haemoglobin concentration of malaria-infected patients in a reference centre in the Brazilian Amazon. Mem Inst Oswaldo Cruz 2014; 109:569-76. [PMID: 25141283 PMCID: PMC4156450 DOI: 10.1590/0074-0276140132] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Accepted: 07/23/2014] [Indexed: 12/28/2022] Open
Abstract
Anaemia is amongst the major complications of malaria, a major public health problem in the Amazon Region in Latin America. We examined the haemoglobin (Hb) concentrations of malaria-infected patients and compared it to that of malaria-negative febrile patients and afebrile controls. The haematological parameters of febrile patients who had a thick-blood-smear performed at an infectious diseases reference centre of the Brazilian Amazon between December 2009-January 2012 were retrieved together with clinical data. An afebrile community control group was composed from a survey performed in a malaria-endemic area. Hb concentrations and anaemia prevalence were analysed according to clinical-epidemiological status and demographic characteristics. In total, 7,831 observations were included. Patients with Plasmodium falciparum infection had lower mean Hb concentrations (10.5 g/dL) followed by P. vivax-infected individuals (12.4 g/dL), community controls (12.8 g/dL) and malaria-negative febrile patients (13.1 g/dL) (p < 0.001). Age, gender and clinical-epidemiological status were strong independent predictors for both outcomes. Amongst malaria-infected individuals, women in the reproductive age had considerably lower Hb concentrations. In this moderate transmission intensity setting, both vivax and falciparum malaria are associated with reduced Hb concentrations and risk of anaemia throughout a wide age range.
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Affiliation(s)
- Andre M Siqueira
- Universidade do Estado do Amazonas, Manaus, AM, Brasil
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Manaus, AM,
Brasil
| | | | - Shelia Vítor-Silva
- Universidade do Estado do Amazonas, Manaus, AM, Brasil
- Universidade Nilton Lins, Manaus, AM, Brasil
| | | | | | - Wuelton M Monteiro
- Universidade do Estado do Amazonas, Manaus, AM, Brasil
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Manaus, AM,
Brasil
| | - Márcia AA Alexandre
- Universidade do Estado do Amazonas, Manaus, AM, Brasil
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Manaus, AM,
Brasil
- Universidade Nilton Lins, Manaus, AM, Brasil
| | - Mourão Maria Paula G
- Universidade do Estado do Amazonas, Manaus, AM, Brasil
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Manaus, AM,
Brasil
| | - Caterina Guinovart
- Clinics Hospital, Barcelona Centre for International Health Research,
University of Barcelona, Barcelona, Spain
| | - Quique Bassat
- Clinics Hospital, Barcelona Centre for International Health Research,
University of Barcelona, Barcelona, Spain
| | - Maria das Graças C Alecrim
- Universidade do Estado do Amazonas, Manaus, AM, Brasil
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Manaus, AM,
Brasil
| | - Marcus VG Lacerda
- Universidade do Estado do Amazonas, Manaus, AM, Brasil
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Manaus, AM,
Brasil
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193
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Epis S, Porretta D, Mastrantonio V, Comandatore F, Sassera D, Rossi P, Cafarchia C, Otranto D, Favia G, Genchi C, Bandi C, Urbanelli S. ABC transporters are involved in defense against permethrin insecticide in the malaria vector Anopheles stephensi. Parasit Vectors 2014; 7:349. [PMID: 25073980 PMCID: PMC4124152 DOI: 10.1186/1756-3305-7-349] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 07/15/2014] [Indexed: 11/18/2022] Open
Abstract
Background Proteins from the ABC family (ATP-binding cassette) represent the largest known group of efflux pumps, responsible for transporting specific molecules across lipid membranes in both prokaryotic and eukaryotic organisms. In arthropods they have been shown to play a role in insecticide defense/resistance. The presence of ABC transporters and their possible association with insecticide transport have not yet been investigated in the mosquito Anopheles stephensi, the major vector of human malaria in the Middle East and South Asian regions. Here we investigated the presence and role of ABCs in transport of permethrin insecticide in a susceptible strain of this mosquito species. Methods To identify ABC transporter genes we obtained a transcriptome from untreated larvae of An. stephensi and then compared it with the annotated transcriptome of Anopheles gambiae. To analyse the association between ABC transporters and permethrin we conducted bioassays with permethrin alone and in combination with an ABC inhibitor, and then we investigated expression profiles of the identified genes in larvae exposed to permethrin. Results Bioassays showed an increased mortality of mosquitoes when permethrin was used in combination with the ABC-transporter inhibitor. Genes for ABC transporters were detected in the transcriptome, and five were selected (AnstABCB2, AnstABCB3, AnstABCB4, AnstABCmember6 and AnstABCG4). An increased expression in one of them (AnstABCG4) was observed in larvae exposed to the LD50 dose of permethrin. Contrary to what was found in other insect species, no up-regulation was observed in the AnstABCB genes. Conclusions Our results show for the first time the involvement of ABC transporters in larval defense against permethrin in An. stephensi and, more in general, confirm the role of ABC transporters in insecticide defense. The differences observed with previous studies highlight the need of further research as, despite the growing number of studies on ABC transporters in insects, the heterogeneity of the results available at present does not allow us to infer general trends in ABC transporter-insecticide interactions. Electronic supplementary material The online version of this article (doi:10.1186/1756-3305-7-349) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Claudio Bandi
- Department of Veterinary Science and Public Health, University of Milan, Milan, Italy.
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194
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A review of malaria transmission dynamics in forest ecosystems. Parasit Vectors 2014; 7:265. [PMID: 24912923 PMCID: PMC4057614 DOI: 10.1186/1756-3305-7-265] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 05/23/2014] [Indexed: 12/25/2022] Open
Abstract
Malaria continues to be a major health problem in more than 100 endemic countries located primarily in tropical and sub-tropical regions around the world. Malaria transmission is a dynamic process and involves many interlinked factors, from uncontrollable natural environmental conditions to man-made disturbances to nature. Almost half of the population at risk of malaria lives in forest areas. Forests are hot beds of malaria transmission as they provide conditions such as vegetation cover, temperature, rainfall and humidity conditions that are conducive to distribution and survival of malaria vectors. Forests often lack infrastructure and harbor tribes with distinct genetic traits, socio-cultural beliefs and practices that greatly influence malaria transmission dynamics. Here we summarize the various topographical, entomological, parasitological, human ecological and socio-economic factors, which are crucial and shape malaria transmission in forested areas. An in-depth understanding and synthesis of the intricate relationship of these parameters in achieving better malaria control in various types of forest ecosystems is emphasized.
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195
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Laothamatas J, Sammet CL, Golay X, Van Cauteren M, Lekprasert V, Tangpukdee N, Krudsood S, Leowattana W, Wilairatana P, Swaminathan SV, DeLaPaz RL, Brown TR, Looareesuwan S, Brittenham GM. Transient lesion in the splenium of the corpus callosum in acute uncomplicated falciparum malaria. Am J Trop Med Hyg 2014; 90:1117-1123. [PMID: 24615139 PMCID: PMC4047739 DOI: 10.4269/ajtmh.13-0665] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Accepted: 02/07/2014] [Indexed: 02/05/2023] Open
Abstract
Patients with acute uncomplicated Plasmodium falciparum malaria have no evident neurologic disorder, vital organ dysfunction, or other severe manifestations of infection. Nonetheless, parasitized erythrocytes cytoadhere to the endothelium throughout their microvasculature, especially within the brain. We aimed to determine if 3 Tesla magnetic resonance imaging studies could detect evidence of cerebral abnormalities in these patients. Within 24 hours of admission, initial magnetic resonance imaging examinations found a lesion with restricted water diffusion in the mid-portion of the splenium of the corpus callosum of 4 (40%) of 10 male patients. The four patients who had a splenial lesion initially had evidence of more severe hemolysis and thrombocytopenia than the six patients who had no apparent abnormality. Repeat studies four weeks later found no residua of the lesions and resolution of the hematologic differences. These observations provide evidence for acute cerebral injury in the absence of severe or cerebral malaria.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | - Sornchai Looareesuwan
- Department of Radiology, Faculty of Medicine Ramathibodi Hospital, Bangkok, Thailand; Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois; Institute of Neurology, University College London, London, United Kingdom; Philips Healthcare, Best, The Netherlands; The Hospital for Tropical Diseases, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Departments of Radiology and Pediatrics and Medicine, Columbia University College of Physicians and Surgeons, New York, New York; Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, South Carolina
| | - Gary M. Brittenham
- Department of Radiology, Faculty of Medicine Ramathibodi Hospital, Bangkok, Thailand; Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois; Institute of Neurology, University College London, London, United Kingdom; Philips Healthcare, Best, The Netherlands; The Hospital for Tropical Diseases, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Departments of Radiology and Pediatrics and Medicine, Columbia University College of Physicians and Surgeons, New York, New York; Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, South Carolina
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196
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Goo YK, Ji SY, Shin HI, Moon JH, Cho SH, Lee WJ, Kim JY. First evaluation of glucose-6-phosphate dehydrogenase (G6PD) deficiency in vivax malaria endemic regions in the Republic of Korea. PLoS One 2014; 9:e97390. [PMID: 24853873 PMCID: PMC4031118 DOI: 10.1371/journal.pone.0097390] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Accepted: 04/18/2014] [Indexed: 11/18/2022] Open
Abstract
Background Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common human enzyme defect and affects more than 400 million people worldwide. This deficiency is believed to protect against malaria because its global distribution is similar. However, this genetic disorder may be associated with potential hemolytic anemia after treatment with anti-malarials, primaquine or other 8-aminoquinolines. Although primaquine is used for malaria prevention, no study has previously investigated the prevalence of G6PD variants and G6PD deficiency in the Republic of Korea (ROK). Methods Two commercialized test kits (Trinity G-6-PDH and CareStart G6PD test) were used for G6PD deficiency screening. The seven common G6PD variants were investigated by DiaPlexC kit in blood samples obtained living in vivax malaria endemic regions in the ROK. Results Of 1,044 blood samples tested using the CareStart G6PD test, none were positive for G6PD deficiency. However, a slightly elevated level of G6PD activity was observed in 14 of 1,031 samples tested with the Trinity G-6-PDH test. Forty-nine of the 298 samples with non-specific amplification by DiaPlexC kit were confirmed by sequencing to be negative for the G6PD variants. Conclusions No G6PD deficiency was observed using phenotypic- or genetic-based tests in individuals residing in vivax malaria endemic regions in the ROK. Because massive chemoprophylaxis using primaquine has been performed in the ROK military to kill hypnozoites responsible for relapse and latent stage vivax malaria, further regular monitoring is essential for the safe administration of primaquine.
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Affiliation(s)
- Youn-Kyoung Goo
- Division of Malaria and Parasitic Diseases, National Institute of Health, Korea CDC, Osong Saeng-myeong 2 ro, Osong Health Technology Administration, Osong, Republic of Korea
- Department of Parasitology and Tropical Medicine, Kyungpook National University School of Medicine, Daegu, Republic of Korea
| | - So-Young Ji
- Division of Malaria and Parasitic Diseases, National Institute of Health, Korea CDC, Osong Saeng-myeong 2 ro, Osong Health Technology Administration, Osong, Republic of Korea
| | - Hyun-Il Shin
- Division of Malaria and Parasitic Diseases, National Institute of Health, Korea CDC, Osong Saeng-myeong 2 ro, Osong Health Technology Administration, Osong, Republic of Korea
| | - Jun-Hye Moon
- Division of Malaria and Parasitic Diseases, National Institute of Health, Korea CDC, Osong Saeng-myeong 2 ro, Osong Health Technology Administration, Osong, Republic of Korea
| | - Shin-Hyung Cho
- Division of Malaria and Parasitic Diseases, National Institute of Health, Korea CDC, Osong Saeng-myeong 2 ro, Osong Health Technology Administration, Osong, Republic of Korea
| | - Won-Ja Lee
- Division of Malaria and Parasitic Diseases, National Institute of Health, Korea CDC, Osong Saeng-myeong 2 ro, Osong Health Technology Administration, Osong, Republic of Korea
| | - Jung-Yeon Kim
- Division of Malaria and Parasitic Diseases, National Institute of Health, Korea CDC, Osong Saeng-myeong 2 ro, Osong Health Technology Administration, Osong, Republic of Korea
- * E-mail:
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197
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Videnović M, Opsenica DM, Burnett J, Gomba L, Nuss JE, Selaković Ž, Konstantinović J, Krstić M, Šegan S, Zlatović M, Sciotti RJ, Bavari S, Šolaja BA. Second generation steroidal 4-aminoquinolines are potent, dual-target inhibitors of the botulinum neurotoxin serotype A metalloprotease and P. falciparum malaria. J Med Chem 2014; 57:4134-53. [PMID: 24742203 PMCID: PMC4032193 DOI: 10.1021/jm500033r] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Indexed: 01/25/2023]
Abstract
Significantly more potent second generation 4-amino-7-chloroquinoline (4,7-ACQ) based inhibitors of the botulinum neurotoxin serotype A (BoNT/A) light chain were synthesized. Introducing an amino group at the C(3) position of the cholate component markedly increased potency (IC50 values for such derivatives ranged from 0.81 to 2.27 μM). Two additional subclasses were prepared: bis(steroidal)-4,7-ACQ derivatives and bis(4,7-ACQ)cholate derivatives; both classes provided inhibitors with nanomolar-range potencies (e.g., the Ki of compound 67 is 0.10 μM). During BoNT/A challenge using primary neurons, select derivatives protected SNAP-25 by up to 89%. Docking simulations were performed to rationalize the compounds' in vitro potencies. In addition to specific residue contacts, coordination of the enzyme's catalytic zinc and expulsion of the enzyme's catalytic water were a consistent theme. With respect to antimalarial activity, the compounds provided better IC90 activities against chloroquine resistant (CQR) malaria than CQ, and seven compounds were more active than mefloquine against CQR strain W2.
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Affiliation(s)
- Milica Videnović
- Faculty
of Chemistry, University of Belgrade, Studentski trg 16, P.O. Box 51, 11158, Belgrade, Serbia
| | - Dejan M. Opsenica
- Institute
of Chemistry, Technology, and Metallurgy, University of Belgrade, Njegoseva 12, 11000 Belgrade, Serbia
| | - James
C. Burnett
- Computational
Drug Development Group, Leidos Biomedical
Research, Inc., FNLCR at Frederick, P.O.
Box B, Frederick, Maryland 21701, United States
| | - Laura Gomba
- Department
of Bacteriology, United States Army Medical
Research Institute of Infectious Diseases, 1425 Porter Street, Frederick, Maryland 21702, United States
| | - Jonathan E. Nuss
- Department
of Bacteriology, United States Army Medical
Research Institute of Infectious Diseases, 1425 Porter Street, Frederick, Maryland 21702, United States
| | - Života Selaković
- Faculty
of Chemistry, University of Belgrade, Studentski trg 16, P.O. Box 51, 11158, Belgrade, Serbia
| | - Jelena Konstantinović
- Faculty
of Chemistry Innovative Centre, Studentski trg 12-16, 11158 Belgrade, Serbia
| | - Maja Krstić
- Faculty
of Chemistry, University of Belgrade, Studentski trg 16, P.O. Box 51, 11158, Belgrade, Serbia
| | - Sandra Šegan
- Institute
of Chemistry, Technology, and Metallurgy, University of Belgrade, Njegoseva 12, 11000 Belgrade, Serbia
| | - Mario Zlatović
- Faculty
of Chemistry, University of Belgrade, Studentski trg 16, P.O. Box 51, 11158, Belgrade, Serbia
| | - Richard J. Sciotti
- Division
of Experimental Therapeutics, Walter Reed
Army Institute of Research, Silver
Spring, Maryland 20910, United States
| | - Sina Bavari
- Target
Discovery and Experimental Microbiology, United States Army Medical Research Institute of Infectious Diseases, 1425 Porter Street, Frederick, Maryland 21702, United States
| | - Bogdan A. Šolaja
- Faculty
of Chemistry, University of Belgrade, Studentski trg 16, P.O. Box 51, 11158, Belgrade, Serbia
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198
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Antiplasmodial Effect of Anthocleista vogelii on Albino Mice Experimentally Infected with Plasmodium berghei berghei (NK 65). J Parasitol Res 2014; 2014:731906. [PMID: 24900913 PMCID: PMC4037601 DOI: 10.1155/2014/731906] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Accepted: 04/14/2014] [Indexed: 11/17/2022] Open
Abstract
The objective of the present study was to investigate the antiplasmodial effect of the ethanolic stem bark extract of Anthocleista vogelii at different doses in albino mice infected with Plasmodium berghei berghei (NK 65). Thirty-six mice were divided into six groups of six mice each. Five groups (B1–B3, D, and G) were infected with Plasmodium berghei berghei parasitized red blood cells. Groups D, H, and G served as the controls. Six days after infection, mice in groups B1, B2, and B3 were treated orally with 100, 200, and 400 mg/kg body weight of Anthocleista vogelii, respectively, for six executive days. Group D was treated with 5 mg/kg body weight of chloroquine while Group G was given distilled water. Group H was not infected and was not treated. It served as the normal control. The extracts exhibited significant (P < 0.05) dose-dependent chemosuppression of P. berghei. The extract exhibited average chemosuppressive effects of 48.5%, 78.5%, and 86.6% at dose levels of 100, 200, and 400 mg/kg body weight, respectively. Phytochemical screening of the plant extract revealed the presence of saponins, cardiac glycosides, flavonoids, terpenes, alkaloids, and steroid. The acute toxicity (LD50) of the plant was estimated to be 3162 mg/kg body weight. It showed that the stem bark of A. vogelii possesses antiplasmodial property.
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199
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Cheemadan S, Ramadoss R, Bozdech Z. Role of calcium signaling in the transcriptional regulation of the apicoplast genome of Plasmodium falciparum. BIOMED RESEARCH INTERNATIONAL 2014; 2014:869401. [PMID: 24877144 PMCID: PMC4022301 DOI: 10.1155/2014/869401] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 02/17/2014] [Accepted: 02/17/2014] [Indexed: 12/19/2022]
Abstract
Calcium is a universal second messenger that plays an important role in regulatory processes in eukaryotic cells. To understand calcium-dependent signaling in malaria parasites, we analyzed transcriptional responses of Plasmodium falciparum to two calcium ionophores (A23187 and ionomycin) that cause redistribution of intracellular calcium within the cytoplasm. While ionomycin induced a specific transcriptional response defined by up- or downregulation of a narrow set of genes, A23187 caused a developmental arrest in the schizont stage. In addition, we observed a dramatic decrease of mRNA levels of the transcripts encoded by the apicoplast genome during the exposure of P. falciparum to both calcium ionophores. Neither of the ionophores caused any disruptions to the DNA replication or the overall apicoplast morphology. This suggests that the mRNA downregulation reflects direct inhibition of the apicoplast gene transcription. Next, we identify a nuclear encoded protein with a calcium binding domain (EF-hand) that is localized to the apicoplast. Overexpression of this protein (termed PfACBP1) in P. falciparum cells mediates an increased resistance to the ionophores which suggests its role in calcium-dependent signaling within the apicoplast. Our data indicate that the P. falciparum apicoplast requires calcium-dependent signaling that involves a novel protein PfACBP1.
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Affiliation(s)
- Sabna Cheemadan
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551
| | - Ramya Ramadoss
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551
| | - Zbynek Bozdech
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551
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Oliva CF, Vreysen MJB, Dupé S, Lees RS, Gilles JRL, Gouagna LC, Chhem R. Current status and future challenges for controlling malaria with the sterile insect technique: technical and social perspectives. Acta Trop 2014; 132 Suppl:S130-9. [PMID: 24295892 DOI: 10.1016/j.actatropica.2013.11.019] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 11/19/2013] [Accepted: 11/23/2013] [Indexed: 12/23/2022]
Abstract
The intolerable burden of malaria, when faced with high levels of drug resistance, increasing insecticide resistance and meagre resources at the national level, remains a great public health challenge to governments and the research/control community. Efficient control methods against the vectors of malaria are desperately needed. Control strategies for malaria that integrate the transfer of sterile sperm by released males to wild virgin females with other control tactics are currently being developed, and optimised mass-rearing, irradiation and release techniques are being validated in several field sites. However, the success of this strategy as part of wider pest control or health management programmes strongly depends on gaining public understanding and acceptance. Here we attempt to review what progress has been made and the remaining challenges surrounding the use of the sterile insect technique against malaria from technical and social perspectives.
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Affiliation(s)
- Clelia F Oliva
- Insect Pest Control Laboratory, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Vienna, Austria; MIVEGEC (IRD 224-CNRS 5290-UM1-UM2) Montpellier, Montpellier, France; Centre de Recherche et de Veille sur les Maladies Emergentes dans l'Océan Indien, 2 rue Maxime Rivière, 97490 Sainte Clotilde, La Réunion, France.
| | - Marc J B Vreysen
- Insect Pest Control Laboratory, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Vienna, Austria.
| | - Sandrine Dupé
- Centre de Recherche et de Veille sur les Maladies Emergentes dans l'Océan Indien, 2 rue Maxime Rivière, 97490 Sainte Clotilde, La Réunion, France; Langues, textes et communication dans les espaces Créolophones et Francophones (EA 4549), Université de La Réunion, Saint Denis, France; Eco-anthropologie et Ethnobiologie (UMR 7206), Muséum National d'Histoire Naturelle, Paris, France.
| | - Rosemary S Lees
- Insect Pest Control Laboratory, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Vienna, Austria.
| | - Jeremie R L Gilles
- Insect Pest Control Laboratory, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Vienna, Austria.
| | - Louis-Clement Gouagna
- MIVEGEC (IRD 224-CNRS 5290-UM1-UM2) Montpellier, Montpellier, France; Centre de Recherche et de Veille sur les Maladies Emergentes dans l'Océan Indien, 2 rue Maxime Rivière, 97490 Sainte Clotilde, La Réunion, France.
| | - Rethy Chhem
- Division of Human Health, Department of Nuclear Science and Applications, International Atomic Energy Agency, Vienna, Austria; Institute of the History, Philosophy and Ethics of Medicine, Ulm University, Ulm, Germany.
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