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Estimating the local spatio-temporal distribution of malaria from routine health information systems in areas of low health care access and reporting
No full textBackground Reliable surveillance systems are essential for identifying disease outbreaks and allocating resources to ensure universal access to diagnostics and treatment for endemic diseases. Yet, most countries with high disease burdens rely entirely on facility-based passive surveillance systems, which miss the vast majority of cases in rural settings with low access to health care. This is especially true for malaria, for which the World Health Organization estimates that routine surveillance detects only 14% of global cases. The goal of this study was to develop a novel method to obtain accurate estimates of disease spatio-temporal incidence at very local scales from routine passive surveillance, less biased by populations' financial and geographic access to care. Methods We use a geographically explicit dataset with residences of the 73,022 malaria cases confirmed at health centers in the Ifanadiana District in Madagascar from 2014 to 2017. Malaria incidence was adjusted to account for underreporting due to stock-outs of rapid diagnostic tests and variable access to healthcare. A benchmark multiplier was combined with a health care utilization index obtained from statistical models of non-malaria patients. Variations to the multiplier and several strategies for pooling neighboring communities together were explored to allow for fine-tuning of the final estimates. Separate analyses were carried out for individuals of all ages and for children under five. Cross-validation criteria were developed based on overall incidence, trends in financial and geographical access to health care, and consistency with geographic distribution in a district-representative cohort. The most plausible sets of estimates were then identified based on these criteria. Results Passive surveillance was estimated to have missed about 4 in every 5 malaria cases among all individuals and 2 out of every 3 cases among children under five. Adjusted malaria estimates were less biased by differences in populations' financial and geographic access to care. Average adjusted monthly malaria incidence was nearly four times higher during the high transmission season than during the low transmission season. By gathering patient-level data and removing systematic biases in the dataset, the spatial resolution of passive malaria surveillance was improved over ten-fold. Geographic distribution in the adjusted dataset revealed high transmission clusters in low elevation areas in the northeast and southeast of the district that were stable across seasons and transmission years. Conclusions Understanding local disease dynamics from routine passive surveillance data can be a key step towards achieving universal access to diagnostics and treatment. Methods presented here could be scaled-up thanks to the increasing availability of e-health disease surveillance platforms for malaria and other diseases across the developing world
Whole-genome assemblies of 16 Burkholderia pseudomallei isolates from rivers in Laos
No full textWe report 16 Burkholderia pseudomallei genomes, including 5 new multi-locus sequence types, isolated from rivers in Laos. The environmental bacterium B. pseudomallei causes melioidosis, a serious infectious disease in tropical and subtropical regions. The isolates are geographically clustered in one Glade from around Vientiane, Laos, and one Glade from further south
Estimating fishing effort in small-scale fisheries using GPS tracking data and random forests
No full textDuring the last decade spatial patterns of industrial fisheries have been increasingly characterized using tracking technologies and machine learning analytical algorithms. In contrast, for small-scale fisheries, fishers' behaviour for estimating and mapping fishing effort has only been anecdotally explored. Following a comparative approach, we conducted a boat tracking survey in a small-scale reef fishery in Madagascar and investigated the performance of a learning random forest algorithm and a speed threshold for estimating and mapping fishing effort. We monitored the movements of a sample of 31 traditional sailing fishing boats at around 45 s time interval using small GPS trackers. A total of 306 daily tracks were recorded among five gear types (beach seine, mosquito trawl net, gillnet, handline, and speargun). To ground-truth GPS location data, fishers' behaviour was simultaneously recorded by a single on-board observer for 49 tracks. Typical, gear-specific track patterns were observed. Overall, the random forest model was found to be the most reliable, generic, and complex method for processing boat GPS tracks and detecting spatially-explicit fishing events regardless gear type. Predictions of mean fishing effort per trip showed that both methods reached from 89.4% to 97.0% accuracy across gear types. Our findings showed that boat tracking combined with on-board observation would improve the reliability of spatial fishing effort indicators in small-scale fisheries and contribute to more efficient management. Selection of the most appropriate GPS data processing method is dependent on local gear use, fishing effort indicators, and available analytical expertise
Description of participants in the "Atout Age Mobility" prevention workshops at the University Hospital Center of La Réunion : a prospective study
No full textIntroduction As the population ages, loss of autonomy is becoming a priority public health issue. "Atout Age Mobility" prevention interventions for seniors aim to limit frailty, which is a predictive and reversible factor in the loss of autonomy and disability. Objectives The objective of this study is to describe the impact of these interventions on the physical performance and quality of life of a pilot sample of participants. Design We conducted a prospective study named 5P PILOT with 3 months of follow up. Settings Subjects were recruited by convenience sampling from participants in the "Atout Age Mobility" workshops at Saint Joseph from 04/09/2017 to 29/01/2019. Participants Retired people over 55 years old with no contraindications to physical activity recruited from participants in the "Atout Age Mobility" workshops in Saint Joseph. Intervention(s) (for clinical trials) or Exposure(s) (for observational studies): All participants completed 12 weeks of physical exercise called the "Atout Age Mobility" workshop, which lasted 60 minutes each week and was supervised by physical activity coaches. Main Outcome(s) and Measure(s) Physical performance was assessed by Short physical performance battery (SPPB), 10-m gait speed and grip strength measurement. Quality of life through the SF-36 test. Results Ninety-six patients were included and 55 (57.3%) completed the study. There was a significant improvement in gait speed (1.35 +/- 0.26m/s vs. 1.27 +/- 0.24m/s; p=0.008). There was no significant change in SF-36, grip strength dominant arm and SPPB at the 0.01 significance level. Conclusion The "Atout Ages Mobility" workshops seem to significantly improve gait speed but not other aspects of physical performance or quality of life
Sustainability determinants of the Burkinabe performance-based financing project
No full textPurpose A performance-based financing (PBF) pilot project was implemented in 2011 in Burkina Faso. After more than five years of implementation (data collection in 2016), the project's sustainability was not guaranteed. This study's objective is to assess this project's sustainability in 2016 by identifying the presence/absence of different determinants of sustainability according to the conceptual framework of Seppey et al. (2017). Design/methodology/approach It uses a case study approach using in-depth interviews with various actors at the local, district/regional and national levels. Participants (n = 37) included health practitioners, management team members, implementers and senior members of health directions. A thematic analysis based on the conceptual framework was conducted, as well as an inductive analysis. Findings Results show the project's sustainability level was weak according to an unequal presence of sustainability's determinants; some activities are being maintained but not fully routinised. Discrepancies between the project and the context's values appeared to be important barriers towards sustainability. Project's ownership by key stakeholders also seemed superficial despite the implementers' leadership towards its success. The project's objective towards greater autonomy for health centres was also directly confronting the Burkinabe's hierarchical health system. Originality/value This study reveals many fits and misfits between a PBF project and its context affecting its ability to sustain activities through time. It also underlines the importance of using a conceptual framework in implementing and evaluating interventions. These results could be interesting for decision-makers and implementers in further assessing PBF projects elsewhere
Social structure, habitat use and injuries of Indo-Pacific bottlenose dolphins (Tursiops aduncus) reveal isolated, coastal, and threatened communities in the South Pacific
No full textUnderstanding population structure and habitat use of poorly known cetacean species is a first step toward scientifically informed management decisions. In the southern range of New Caledonia (South Pacific), a long-term dataset of Indo-Pacific bottlenose dolphins (Tursiops aduncus) encounters primarily during winter seasons 1997 to 2019 (473 group observations) was used to assess social structure, habitat use and potential threats. A total of 338 individuals were photographically identified, forming three distinct communities in the south-west lagoon, the south lagoon and the Isle of Pines. Mark-recapture histories revealed that the three communities were weakly connected and might be considered as independent management units. Suitable habitats were estimated with presence-only distribution models relative to topographic and seabed substrate predictors. Habitat suitability increased with proximity to coasts or reefs, at shallow depth, and over muddy bottom. These habitats had various levels of protection and were used by humans, mostly in the south-west lagoon. External injuries were interpreted to determine natural interactions and potential anthropogenic threats. The prevalence in injuries did not vary among the three areas. A substantial proportion of injuries related to propeller hits was reported, representing a total of 16.7% (34 of 204) of all injuries observed on dolphins. The three communities of Indo-Pacific bottlenose dolphins revealed in the southern part of New Caledonia are particularly vulnerable due to their insularity, their coastal habitat use and the low levels of connectivity found among them. In a context of increasing maritime traffic, fishing and recreational activities, this study provides a useful baseline to the urgent assessment of the conservation status of dolphins in New Caledonia
Model physics and chemistry causing intermodel disagreement within the VolMIP-Tambora Interactive Stratospheric Aerosol ensemble
No full textAs part of the Model Intercomparison Project on the climatic response to Volcanic forcing (VolMIP), several climate modeling centers performed a coordinated pre-study experiment with interactive stratospheric aerosol models simulating the volcanic aerosol cloud from an eruption resembling the 1815 Mt. Tambora eruption (VolMIP-Tambora ISA ensemble). The pre-study provided the ancillary ability to assess intermodel diversity in the radiative forcing for a large stratospheric-injecting equatorial eruption when the volcanic aerosol cloud is simulated interactively. An initial analysis of the VolMIP-Tambora ISA ensemble showed large disparities between models in the stratospheric global mean aerosol optical depth (AOD). In this study, we now show that stratospheric global mean AOD differences among the participating models are primarily due to differences in aerosol size, which we track here by effective radius. We identify specific physical and chemical processes that are missing in some models and/or parameterized differently between models, which are together causing the differences in effective radius. In particular, our analysis indicates that interactively tracking hydroxyl radical (OH) chemistry following a large volcanic injection of sulfur dioxide (SO2) is an important factor in allowing for the timescale for sulfate formation to be properly simulated. In addition, depending on the timescale of sulfate formation, there can be a large difference in effective radius and subsequently AOD that results from whether the SO2 is injected in a single model grid cell near the location of the volcanic eruption, or whether it is injected as a longitudinally averaged band around the Earth
Remotely sensed phenology monitoring and land-cover classification for the localization of the endemic argan tree in the Southern-west of Morocco
No full textArgania spinosa also known as the argan tree is an endemic plant of Morocco. Despite having the ability to subsist in extreme drought conditions, it is threatened by soil land clearing, overexploitation, and absence of natural regeneration, causing a worrying decline in both spatial extent and density. The spatial extent of dryland forests is debated, as estimates of forest areas in drylands are uncertain. The present study aims to map and locate the spatial distribution of the argan trees at Smimou community located in Essaouira province, south-eastern Morocco, using satellite images and a double-classification process to overcome separability problems. The work focuses on the characterization and comparison of the unique phenological patterns of argan with the other present land-cover classes. NDVI products were derived from a Sentinel-2 time-series covering one year (2018 to 2019), then ground samples were used to extract phenological profiles at parcel level then at tree level, to feed representative calibration samples to Support Vector Machine classifier. The outcome was integrated with an elevation model in a Decision Tree to reclassify mixed areas. The results indicated an F1-score and an overall accuracy of 91.27% and 92.60% respectively, a promising technique for updating argan extent at national scale
Community intervention for child tuberculosis active contact investigation and management : study protocol for a parallel cluster randomized controlled trial
No full textBackground: There are major gaps in the management of pediatric tuberculosis (TB) contact investigation for rapid identification of active tuberculosis and initiation of preventive therapy. This study aims to evaluate the impact of a community-based intervention as compared to facility-based model for the management of children in contact with bacteriologically confirmed pulmonary TB adults in low-resource high-burden settings. Methods/design: This multicenter parallel open-label cluster randomized controlled trial is composed of three phases: I, baseline phase in which retrospective data are collected, quality of data recording in facility registers is checked, and expected acceptability and feasibility of the intervention is assessed; II, intervention phase with enrolment of index cases and contact cases in either facility- or community-based models; and III, explanatory phase including endpoint data analysis, cost-effectiveness analysis, and post-intervention acceptability assessment by healthcare providers and beneficiaries. The study uses both quantitative and qualitative analysis methods. The community-based intervention includes identification and screening of all household contacts, referral of contacts with TB-suggestive symptoms to the facility for investigation, and household initiation of preventive therapy with follow-up of eligible child contacts by community healthcare workers, i.e., all young (< 5 years) child contacts or older (5-14 years) child contacts living with HIV, and with no evidence of TB disease. Twenty clusters representing TB diagnostic and treatment facilities with their catchment areas are randomized in a 1:1 ratio to either the community-based intervention arm or the facility-based standard of care arm in Cameroon and Uganda. Randomization was stratified by country and constrained on the number of index cases per cluster. The primary endpoint is the proportion of eligible child contacts who initiate and complete the preventive therapy. The sample size is of 1500 child contacts to identify a 10% difference between the arms with the assumption that 60% of children will complete the preventive therapy in the standard of care arm. Discussion: This study will provide evidence of the impact of a community-based intervention on household child contact screening and management of TB preventive therapy in order to improve care and prevention of childhood TB in low-resource high-burden settings
Impacts on greenhouse gas balance and rural economy after agroecology development in Itasy Madagascar
No full textRural development projects to develop sustainable agriculture need to be assessed before engaging small holder farmers at large scale. Data on agricultural systems to produce food, provide income for small holders and reduce greenhouse-gas (GHG) emissions are scarce in Sub-Saharan Africa countries. Here, we assessed the potential of agroecological practices (AP) on economic benefits to farmers, GHG balance derived from agricultural activities, and efficiency of economic investments to mitigate GHG. The study was based on a NGO rural development project, which promoted AP: agroforestry, compost, andSystem of Rice Intensification. The economic and GHG mitigation benefits were projected over a periodof 20 years on three scenarios. Two scenarios, differing by two expected levels of AP adoption, werecompared to a reference one, in which there was no NGO intervention. Socio-economic, yield and soildata were gathered on 192 farms duringfive growing seasons (2013-2018). The GHG balance wasestimated with TropiC Farm Tool and EX-ACT. The GHG emissions were reduced in both scenarioscompared to the reference one:-5.2 to-13.6 tCO2eq farm-1yr-1for scenario 1 and 2 respectively. Atthe regional scale, the projected amount of C saved per euro invested was estimated at-0.25 tCO2eqeuro-1and -0.41 tCO2eq Euro-1(orV4 to 2.5 tCO2eq-1) under scenario 1 and scenario 2. The annualcashflow of farmers increased over the 20 years. Our study highlighted the potential of AP for increasing productivity and profitability of small holder agricultural systems for the Malagasy farmers, while simultaneously contributing to climate change mitigatio