scholarly journals Genetic surveillance in the Greater Mekong Subregion and South Asia to support malaria control and elimination

Author(s):  
Christopher G Jacob ◽  
Nguyen Thuy-Nhien ◽  
Mayfong Mayxay ◽  
Richard J Maude ◽  
Huynh Hong Quang ◽  
...  

ABSTRACTThe use of parasite genetic data by National Malaria Control Programmes (NMCPs) is currently limited, and typically focused on specific genetic features or a small number of study sites. We have developed GenRe-Mekong, a platform for genetic surveillance of malaria in the Greater Mekong Subregion (GMS). By integrating simple sample collection procedures in the routine operations of public health facilities, GenRe-Mekong enables NMCPs to conduct large-scale surveillance project in endemic regions. Samples are processed by the SpotMalaria platform, which uses high-throughput technologies to produce a broad set of genotypes, including most known drug resistance markers, species markers and a genomic barcode. Through the application of heuristics based on published evidence, GenRe-Mekong delivers Genetic Report Cards, a compendium of genotypes and phenotype predictions that are used to map prevalence of resistance to multiple drugs. To date, GenRe-Mekong has worked with NMCPs in five countries, and with several large-scale research projects, processing 9,623 samples from clinical cases. The monitoring of resistance markers has been especially valuable for NMCPs tracking the recent rapid spread of DHA-piperaquine resistant parasites across the region. In Vietnam and Laos, data from GenRe-Mekong have provided novel knowledge about the spread of these resistant strains in provinces previously thought to be unaffected. GenRe-Mekong facilitates data sharing by aggregating at regional level results from different countries, providing cross-border views of the spread of resistant strains.

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Christopher G Jacob ◽  
Nguyen Thuy-Nhien ◽  
Mayfong Mayxay ◽  
Richard J Maude ◽  
Huynh Hong Quang ◽  
...  

Background:National Malaria Control Programmes (NMCPs) currently make limited use of parasite genetic data. We have developed GenRe-Mekong, a platform for genetic surveillance of malaria in the Greater Mekong Subregion (GMS) that enables NMCPs to implement large-scale surveillance projects by integrating simple sample collection procedures in routine public health procedures.Methods:Samples from symptomatic patients are processed by SpotMalaria, a high-throughput system that produces a comprehensive set of genotypes comprising several drug resistance markers, species markers and a genomic barcode. GenRe-Mekong delivers Genetic Report Cards, a compendium of genotypes and phenotype predictions used to map prevalence of resistance to multiple drugs.Results:GenRe-Mekong has worked with NMCPs and research projects in eight countries, processing 9623 samples from clinical cases. Monitoring resistance markers has been valuable for tracking the rapid spread of parasites resistant to the dihydroartemisinin-piperaquine combination therapy. In Vietnam and Laos, GenRe-Mekong data have provided novel knowledge about the spread of these resistant strains into previously unaffected provinces, informing decision-making by NMCPs.Conclusions:GenRe-Mekong provides detailed knowledge about drug resistance at a local level, and facilitates data sharing at a regional level, enabling cross-border resistance monitoring and providing the public health community with valuable insights. The project provides a rich open data resource to benefit the entire malaria community.Funding:The GenRe-Mekong project is funded by the Bill and Melinda Gates Foundation (OPP11188166, OPP1204268). Genotyping and sequencing were funded by the Wellcome Trust (098051, 206194, 203141, 090770, 204911, 106698/B/14/Z) and Medical Research Council (G0600718). A proportion of samples were collected with the support of the UK Department for International Development (201900, M006212), and Intramural Research Program of the National Institute of Allergy and Infectious Diseases.


2019 ◽  
Vol 8 (9) ◽  
pp. 1320
Author(s):  
Kazumasa Oda ◽  
Hideshi Okada ◽  
Akio Suzuki ◽  
Hiroyuki Tomita ◽  
Ryo Kobayashi ◽  
...  

Endothelial disorders are related to various diseases. An initial endothelial injury is characterized by endothelial glycocalyx injury. We aimed to evaluate endothelial glycocalyx injury by measuring serum syndecan-1 concentrations in patients during comprehensive medical examinations. A single-center, prospective, observational study was conducted at Asahi University Hospital. The participants enrolled in this study were 1313 patients who underwent comprehensive medical examinations at Asahi University Hospital from January 2018 to June 2018. One patient undergoing hemodialysis was excluded from the study. At enrollment, blood samples were obtained, and study personnel collected demographic and clinical data. No treatments or exposures were conducted except for standard medical examinations and blood sample collection. Laboratory data were obtained by the collection of blood samples at the time of study enrolment. According to nonlinear regression, the concentrations of serum syndecan-1 were significantly related to age (p = 0.016), aspartic aminotransferase concentration (AST, p = 0.020), blood urea nitrogen concentration (BUN, p = 0.013), triglyceride concentration (p < 0.001), and hematocrit (p = 0.006). These relationships were independent associations. Endothelial glycocalyx injury, which is reflected by serum syndecan-1 concentrations, is related to age, hematocrit, AST concentration, BUN concentration, and triglyceride concentration.


2021 ◽  
Author(s):  
Lin Tao ◽  
M. Paul Chiarelli ◽  
Sylvia I. Pavlova ◽  
Joel L. Schwartz ◽  
James V. DeFrancesco ◽  
...  

Abstract Certain soil microbes resist and metabolize polycyclic aromatic hydrocarbons (PAHs). The same is true for certain skin microbes. Oral microbes have the potential to oxidize tobacco PAHs to increase their ability to cause cancer. We hypothesized that oral microbes that resist high levels of PAH in smokers exist and can be identified based on their resistance to PAHs. We isolated bacteria and fungi that survived long term in minimal media with PAHs as the sole carbon source from the oral cavity in 11 of 14 smokers and only 1 of 6 nonsmokers. Of bacteria genera that included species that survived harsh PAH exposure in vitro, all were found at trace levels on the oral mucosa, except for Staphylococcus and Actinomyces. Two PAH-resistant strains of Candida albicans (C. albicans) were isolated from smokers. C. albicans is found orally at high levels in tobacco users and some Candida species can metabolize PAHs. The two C. albicans strains were tested for metabolism of two model PAH substrates, pyrene and phenanthrene. The result showed that the PAH-resistant C. albicans strains did not metabolize the two PAHs. In conclusion, evidence for large scale oral microbial metabolism of tobacco PAHs by common oral microbes remains lacking.


2018 ◽  
Vol 2 ◽  
pp. 32 ◽  
Author(s):  
Su Yun Kang ◽  
Katherine E. Battle ◽  
Harry S. Gibson ◽  
Laura V. Cooper ◽  
Kilama Maxwell ◽  
...  

Background: Heterogeneity in malaria transmission has household, temporal, and spatial components. These factors are relevant for improving the efficiency of malaria control by targeting heterogeneity. To quantify variation, we analyzed mosquito counts from entomological surveillance conducted at three study sites in Uganda that varied in malaria transmission intensity. Mosquito biting or exposure is a risk factor for malaria transmission. Methods: Using a Bayesian zero-inflated negative binomial model, validated via a comprehensive simulation study, we quantified household differences in malaria vector density and examined its spatial distribution. We introduced a novel approach for identifying changes in vector abundance hotspots over time by computing the Getis-Ord statistic on ratios of household biting propensities for different scenarios. We also explored the association of household biting propensities with housing and environmental covariates. Results: In each site, there was evidence for hot and cold spots of vector abundance, and spatial patterns associated with urbanicity, elevation, or other environmental covariates. We found some differences in the hotspots in rainy vs. dry seasons or before vs. after the application of control interventions. Housing quality explained a portion of the variation among households in mosquito counts. Conclusion: This work provided an improved understanding of heterogeneity in malaria vector density at the three study sites in Uganda and offered a valuable opportunity for assessing whether interventions could be spatially targeted to be aimed at abundance hotspots which may increase malaria risk. Indoor residual spraying was shown to be a successful measure of vector control interventions in Tororo, Uganda.  Cement walls, brick floors, closed eaves, screened airbricks, and tiled roofs were features of a house that had shown reduction of household biting propensity. Improvements in house quality should be recommended as a supplementary measure for malaria control reducing risk of infection.


2019 ◽  
Vol 27 (2) ◽  
pp. 100-114
Author(s):  
Attila Bende ◽  
Angéla Király ◽  
Richárd lászló

Abstract Publications about curiosities are known in the Hungarian and international ornithological literature since the 1800s. Although studies explaining the processes of pigmentation dysfunctions have been known since the mid-nineteenth century, these specimens still appear only as curiosities in the professional press and the terminology used to specify them is generally incorrect. The analysed genetic abnormalities causing white colour varieties in Woodcock (albinism, leucism, Ino) are due to mutations. By briefly describing the biological background of the defects, this work helps detect colour changes. In this article, we provide a broad overview of partially or completely white Woodcocks (n = 23 expl.) found in international (8 countries) and Hungarian literature. We have supplemented the literature background with our own studies. The large-scale analysis of the variability of colours and patterns was made possible by the countrywide wing sample collection within the biometric module of Woodcock Monitoring, which has been running under the coordination of the Hungarian Hunting Conservation Association since 2010. Within this framework, 12,078 samples were analysed between 2010–2018. We found that pigment deficiency occurred in the sample set only with a proportion of 0.01%. Based on the Hungarian literature and our own samples, we presented the known occurrences on maps of the state territory with boundaries before and after 1921, indicating the causes of patterns of occurrence by migration and frequencies of occurrence.


2021 ◽  
Author(s):  
Alexandre Gauvain ◽  
Ronan Abhervé ◽  
Jean-Raynald de Dreuzy ◽  
Luc Aquilina ◽  
Frédéric Gresselin

&lt;p&gt;Like in other relatively flat coastal areas, flooding by aquifer overflow is a recurring problem on the western coast of Normandy (France). Threats are expected to be enhanced by the rise of the sea level and to have critical consequences on the future development and management of the territory. The delineation of the increased saturation areas is a required step to assess the impact of climate change locally. Preliminary models showed that vulnerability does not result only from the sea side but also from the continental side through the modifications of the hydrological regime.&lt;/p&gt;&lt;p&gt;We investigate the processes controlling these coastal flooding phenomena by using hydrogeological models calibrated at large scale with an innovative method reproducing the hydrographic network. Reference study sites selected for their proven sensitivity to flooding have been used to validate the methodology and determine the influence of the different geomorphological configurations frequently encountered along the coastal line.&lt;/p&gt;&lt;p&gt;Hydrogeological models show that the rise of the sea level induces an irregular increase in coastal aquifer saturations extending up to several kilometers inland. Back-littoral channels traditionally used as a large-scale drainage system against high tides limits the propagation of aquifer saturation upstream, provided that channels are not dominantly under maritime influence. High seepage fed by increased recharge occurring in climatic extremes may extend the vulnerable areas and further limit the effectiveness of the drainage system. Local configurations are investigated to categorize the influence of the local geological and geomorphological structures and upscale it at the regional scale.&lt;/p&gt;


The Auk ◽  
2000 ◽  
Vol 117 (3) ◽  
pp. 748-759 ◽  
Author(s):  
Caleb E. Gordon

Abstract I used mark-recapture analysis and radio telemetry to characterize winter movement patterns of six grassland sparrows in southeastern Arizona. Mark-recapture data were generated by banding birds captured during repeated flush-netting sessions conducted on a series of 7-ha plots over three consecutive winters. This resulted in 2,641 captures of 2,006 individual sparrows of the six species. Radio telemetry was conducted concurrently on 20 individuals of four of these species. Recapture data and radio telemetry indicated that Cassin's Sparrow (Aimophila cassinii) and Grasshopper Sparrow (Ammodramus savannarum) were the most sedentary, followed by Baird's Sparrow (Ammodramus bairdii), Vesper Sparrow (Pooecetes gramineus), Savannah Sparrow (Passerculus sandwichensis), and Brewer's Sparrow (Spizella breweri). Grasshopper, Baird's, Savannah, and Vesper sparrows tended to remain within fixed home ranges during winter. With the exception of Savannah Sparrows, whose movement behavior varied among study sites, movement patterns remained constant within species across years and study sites despite radical fluctuations in the absolute and relative abundances of all species. Interspecific differences in movement pattern suggest that species in this system partition niche space according to the regional-coexistence mechanism. Abundances of the most sedentary species, Cassin's, Grasshopper, and Baird's sparrows, were poorly or negatively correlated with summer rainfall at the between-year landscape scale, whereas abundances of the more mobile Savannah, Vesper, and Brewer's sparrows were strongly positively correlated. This is consistent with the theoretical prediction that movement constrains large-scale habitat selection, favoring mobile species in fragmented environments.


2020 ◽  
Vol 245 (5) ◽  
pp. 437-447
Author(s):  
Quanah J Hudson ◽  
Alexandra Perricos ◽  
Rene Wenzl ◽  
Iveta Yotova

Endometriosis affects up to 10% of women of childbearing age, causing symptoms that can include chronic pelvic pain and reduced fertility. The symptoms are not specific to the disease and can be confused with other gynecological conditions or normal menstruation. Currently, the disease can be only definitively diagnosed by laparoscopy, as no clinically accepted biomarker exists. Biomarker discovery can either follow a hypothesis-driven approach selecting targets to be tested based on current knowledge of the disease, or take an unbiased high-throughput screening “omics” approach, such as transcriptomics or proteomics, to identify markers that are unique or elevated in accessible bodily fluids of patients with the disease. Numerous studies have been conducted using these approaches to try and identify endometriosis biomarkers, but variabilities in study design, cohort selection, and analysis, together with the fact that most studies were small-scale, have made independent validation of biomarker candidates difficult. Therefore, efforts are underway to standardize cohort selection, patient data, and sample collection to allow better cross-study comparisons. Large scale multi-center studies using this standardized approach are necessary to validate existing endometriosis biomarker candidates and uncover potential new markers. Given the complexity and heterogeneity of the disease, it is likely that a panel of biomarkers will be necessary to diagnose and categorize endometriosis. Impact statement Endometriosis is a common disease affecting reproductive age women, which is associated with chronic pain and reduced fertility reducing the quality of life of many women. Definitive diagnosis requires invasive laparoscopic surgery creating a high barrier to diagnosis that can delay the onset of treatment significantly. Clinically approved biomarkers of endometriosis are currently lacking, making the discovery and validation of biomarkers that would lead to earlier diagnosis a priority for improving treatment of the disease.


2020 ◽  
Vol 17 (3) ◽  
pp. 771-780 ◽  
Author(s):  
Stephanie C. Pennington ◽  
Nate G. McDowell ◽  
J. Patrick Megonigal ◽  
James C. Stegen ◽  
Ben Bond-Lamberty

Abstract. Soil respiration (Rs), the flow of CO2 from the soil surface to the atmosphere, is one of the largest carbon fluxes in the terrestrial biosphere. The spatial variability of Rs is both large and poorly understood, limiting our ability to robustly scale it in space. One factor in Rs spatial variability is the autotrophic contribution from plant roots, but it is uncertain how the presence of plants affects the magnitude and temperature sensitivity of Rs. This study used 1 year of Rs measurements to examine the effect of localized basal area on Rs in the growing and dormant seasons, as well as during moisture-limited times, in a temperate, coastal, deciduous forest in eastern Maryland, USA. In a linear mixed-effects model, tree basal area within a 5 m radius (BA5) exerted a significant positive effect on the temperature sensitivity of soil respiration. Soil moisture was the dominant control on Rs during the dry portions of the year, while soil moisture, temperature, and BA5 all exerted significant effects on Rs in wetter periods. Our results suggest that autotrophic respiration is more sensitive to temperature than heterotrophic respiration at these sites, although we did not measure these source fluxes directly, and that soil respiration is highly moisture sensitive, even in a record-rainfall year. The Rs flux magnitudes (0.46–15.0 µmol m−2 s−1) and variability (coefficient of variability 10 %–23 % across plots) observed in this study were comparable to values observed in similar forests. Six Rs observations would be required in order to estimate the mean across all study sites to within 50 %, and 518 would be required in order to estimate it to within 5 %, with 95 % confidence. A better understanding of the spatial interactions between plants and microbes, as well as the strength and speed of above- and belowground coupling, is necessary to link these processes with large-scale soil-to-atmosphere C fluxes.


Sign in / Sign up

Export Citation Format

Share Document