Seasonal cycles in climatic factors affect drivers of child growth and contribute to seasonal fluctuations in undernutrition. Current growth seasonality models are limited by categorical definitions ...of seasons that rely on assumptions about their timing and fail to consider their magnitude.
We disentangle the relationship between climatic factors and growth indicators, using harmonic regression to determine how child growth is related to peaks in temperature, precipitation, and vegetation.
Longitudinal anthropometric data collected between August 2014 and December 2016 from 5039 Burkinabè children measured monthly from age 6 to 28 mo (108,580 observations) were linked with remotely sensed daily precipitation, vegetation, and maximum air temperature. Our models parsimoniously extract a cyclic signal with multiple potential peaks, to compare the magnitude and timing of seasonal peaks in climatic factors and morbidity with that of nadirs in growth velocity (cm/mo, kg/mo).
Length and weight velocity were slowest twice a year, coinciding both times with the highest temperatures, and peak fever incidence. Length velocity is slowest 13 d after the first temperature peak in April, and 5 d after the second. Similarly, weight velocity is slowest 13 d before the first temperature peak, and 11 d before the second. The statistical relationship between temperature and anthropometry shows that when the current temperature is higher, weight velocity is lower (β = -0.0048; 95% CI: -0.0059, -0.0038), and length velocity is higher (β = 0.0088; 95% CI: 0.0070, 0.0105).
Results suggest that child health and development are more affected by high temperatures than by other aspects of climatic seasonality such as rainfall. Emerging shifts in climatic conditions will pose challenges to optimal growth, highlighting the importance of changes that optimize the timing of nutrition interventions and address environmental growth-limiting conditions.
Clinicaltrials.gov: NCT02071563.
Because of limited data on dengue virus in Burkina Faso, we conducted 4 consecutive age-stratified longitudinal serologic surveys, ≈6 months apart, among persons 1-55 years of age, during June ...2015-March 2017, which included a 2016 outbreak. The seroconversion rate before the serosurvey enrollment was estimated by binomial regression, taking age as the duration of exposure, and assuming constant force of infection (FOI) over age and calendar time. We calculated FOI between consecutive surveys and rate ratios for potentially associated characteristics based on seroconversion using the duration of intervals. Among 2,897 persons at enrollment, 66.3% were IgG-positive, and estimated annual FOI was 5.95%. Of 1,269 enrollees participating in all 4 serosurveys, 438 were IgG-negative at enrollment. The annualized FOI ranged from 10% to 20% (during the 2016 outbreak). Overall, we observed high FOI for dengue. These results could support decision-making about control and preventive measures for dengue.
Background. Plasmodium falciparum gametocytes are essential for malaria transmission. Malaria control measures that aim at reducing transmission require an accurate characterization of the human ...infectious reservoir. Methods. We longitudinally determined human infectiousness to mosquitoes and P. falciparum carriage by an ultrasensitive RNA-based diagnostics in 130 randomly selected inhabitants of an endemic area. Results. At least 1 mosquito was infected by 32.6% (100 of 307) of the blood samples; in total, 7.6% of mosquitoes (916 of 12 079) were infected. The proportion of infectious individuals and infected mosquitoes were negatively associated with age and positively with asexual parasites (P < .001). Human infectiousness was higher at the start of the wet season and subsequently declined at the peak of the wet season (adjusted odds ratio, 0.52; P = .06) and in the dry season (0.23; P < .001). Overall, microscopy-negative individuals were responsible for 28.7% of infectious individuals (25 of 87) and 17.0% of mosquito infections (145 of 855). Conclusions. Our study reveals that the infectious reservoir peaks at the start of the wet season, with prominent roles for infections in children and submicroscopic infections. These findings have important consequences for strategies and the timing of interventions, which need to include submicroscopic infections and be implemented in the dry season.
In Sahelian landscapes, land use/land cover (LULC) dynamics and climate variability are already known to affect the water cycle. In its current practice however, hydrological modelling does not ...account for LULC changes. This issue pertains to rapidly evolving watersheds and might result in critical inaccuracies in the simulated processes. In this study, the Soil and Water Assessment Tool (SWAT) model was used to simulate surface runoff in the small Sahelian watershed of Tougou, which underwent significant LULC changes between 1952 and 2017. Based on rainfall/runoff data acquired from 2004 to 2018, the SWAT model was calibrated under two scenarios: a static land use scenario (SLU) using a single LULC map (in 1999) and a dynamic land use scenario (DLU) integrating 3 LULC maps (1999, 2009 and 2017). The DLU scenario estimated with higher accuracy surface runoff, deep aquifer infiltration and actual evapotranspiration processes. Based on the calibrated parameters, surface runoff was simulated during the historical period 1952–2003 under four scenarios with static LULC maps (in 1952, 1973, 1986 and 1999) opposed to a fifth scenario integrating these LULC maps dynamically. The DLU scenario was found to be more effective at picturing the so-called Sahelian paradox (i.e. the increase in surface runoff despite the decrease in rainfall), reported in the literature for small watersheds in the Sahel. The analysis of variability revealed that fluctuations in surface runoff were both influenced by rainfall and LULC changes. Furthermore, the isolated contributions of climate variability and LULC changes on surface runoff showed that LULC conditions played a dominant role (ηlulc = +393.1%) in the runoff increase over climate (ηcl = −297%) during the historical period. These results highlight the importance of accounting for LULC dynamics in hydrological modelling and advocate the development of integrated modelling frameworks for hydrologists and water resource managers.
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•The impact of static and dynamic LULC on a model calibration is assessed.•The Sahelian paradox is simulated effectively with a dynamic LULC scenario.•The runoff increase in Tougou is mainly due to LULC changes during 1952–2003.•Isolated effects of climate variability and LULC change on runoff are quantified.
The performance of seven operational high-resolution satellite-based rainfall products - Africa Rainfall Estimate Climatology (ARC 2.0), Climate Hazards Group InfraRed Precipitation with Stations ...(CHIRPS), Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN), African Rainfall Estimation (RFE 2.0), Tropical Applications of Meteorology using SATellite (TAMSAT), African Rainfall Climatology and Time-series (TARCAT), and Tropical Rainfall Measuring Mission (TRMM) daily and monthly estimates - was investigated for Burkina Faso. These were compared to ground data for 2001-2014 on a point-to-pixel basis at daily to annual time steps. Continuous statistics was used to assess their performance in estimating and reproducing rainfall amounts, and categorical statistics to evaluate rain detection capabilities. The north-south gradient of rainfall was captured by all products, which generally detected heavy rainfall events, but showed low correlation for rainfall amounts. At daily scale they performed poorly. As the time step increased, the performance improved. All (except TARCAT) provided excellent scores for Bias and Nash-Sutcliffe Efficiency coefficients, and overestimated rainfall amounts at the annual scale. RFE performed the best, whereas TARCAT was the weakest. Choice of product depends on the specific application: ARC, RFE, and TARCAT for drought monitoring, and PERSIANN, CHIRPS, and TRMM daily for flood monitoring in Burkina Faso.
There are no data on type 1 diabetes (T1D) incidence and prevalence in Burkina Faso. We aimed to determine these in persons aged <25 years (y) since the implementation of Life for a Child (LFAC) ...program in 2013.
Data were collected from the prospective program register. Diagnosis of T1D was clinical, based on presentation, abrupt onset of symptomatic hyperglycemia, need for insulin replacement therapy from diagnosis, and no suggestion of other diabetes types.
We diagnosed 312 cases of T1D <25y in 2013–2022. Male-to-female ratio was 1:1. T1D incidence <25y per 100,000 population/year increased from 0.08 (CI 95% 0.07-0.60) in 2013 to 0.34 (CI 95% 0.26-0.45) in 2022 (p=0.002). Incidence <15y/y rose from 0.04 (CI 95% 0.01-0.10) to 0.27 (CI 95% 0.18-0.38) per 100,000/year in 2013 and 2022, respectively (p < 0.002). Prevalence per 100,000 population <25y was 0.27 (CI 95% 0.19-0.37) in 2013 and rose to 1.76 (CI 95% 1.546-1.99) in 2022 (p<0.0001). Mortality rate was 20 (CI 95% 13-29.6) per 1,000-person y.
There is a low but sharply rising T1D incidence and prevalence rates in children and youth in Burkina Faso since LFAC program implementation. It is very likely this is partly due to improved case detection. Mortality remains substantial.
Widespread acceptance of COVID-19 vaccines is crucial for achieving sufficient immunization coverage to end the global pandemic, yet few studies have investigated COVID-19 vaccination attitudes in ...lower-income countries, where large-scale vaccination is just beginning. We analyze COVID-19 vaccine acceptance across 15 survey samples covering 10 low- and middle-income countries (LMICs) in Asia, Africa and South America, Russia (an upper-middle-income country) and the United States, including a total of 44,260 individuals. We find considerably higher willingness to take a COVID-19 vaccine in our LMIC samples (mean 80.3%; median 78%; range 30.1 percentage points) compared with the United States (mean 64.6%) and Russia (mean 30.4%). Vaccine acceptance in LMICs is primarily explained by an interest in personal protection against COVID-19, while concern about side effects is the most common reason for hesitancy. Health workers are the most trusted sources of guidance about COVID-19 vaccines. Evidence from this sample of LMICs suggests that prioritizing vaccine distribution to the Global South should yield high returns in advancing global immunization coverage. Vaccination campaigns should focus on translating the high levels of stated acceptance into actual uptake. Messages highlighting vaccine efficacy and safety, delivered by healthcare workers, could be effective for addressing any remaining hesitancy in the analyzed LMICs.
•Mangodara forms a dome cored by tonalitic gneiss, mantled by granodioritic gneiss.•Gneiss-granitoids derive from partial melting of Birimian greenstones.•Residual melt from syntectonic gneiss ...genesis formed rare-metal pegmatites.
We describe the geological context of rare metal-bearing pegmatites from the Mangodara district (South-West Burkina Faso, Paleoproterozoic West African Craton) and discuss their petrogenesis and links with the host rocks. The Mangodara district exposes a gneiss-granitoid complex structured in a regional-scale dome, mantled by granodioritic gneiss enclosing rafts of amphibolite, micaschist and paragneiss, and cored by tonalitic to trondhjemitic gneisses. These gneisses enclose granitoid plutons, and four populations of rare metal-bearing pegmatites: titanite-allanite-, apatite-zircon-, garnet-columbite (Li, Nb) and garnet-REE (Ti, Y, HREE)-bearing varieties.
Rafts of migmatitic amphibolite, micaschist and paragneiss are chemically equivalent to nearby Birimian greenstone belts. An origin of the gneiss-granitoid complex by partial melting is suggested by diffuse contacts of rafts with the gneisses as well as the presence of garnet-bearing or hornblende-bearing leucosome in paragneiss and in amphibolites, respectively. Textural continuity between pegmatites and granitic veins concordant to the foliation of the gneisses point to syntectonic segregation of the pegmatite-forming magmas.
The compositions of gneisses and plutonic rocks spread between a Na-rich pole and a K-rich pole. Granodioritic gneiss, hornblende-biotite granodiorite and potassic biotite granitoids define a K-rich series attributed to relatively low-pressure high-degree partial melting of dominantly paragneiss, which accounts for low to absent LILE and HFSE fractionation compared to the paragneiss. Tonalitic-trondhjemitic gneiss, a biotite trondhjemite and a peraluminous two-mica trondhjemite belong to a Na-rich series characterized by low K content and strong depletion in REE and HFSE, which might reflect plagioclase clustering after partial melting at a relatively high pressure of amphibolite, and fractionation of HFSE-REE-bearing minerals. Thermodynamic and mass balance modeling further corroborate these propositions implying that partial melting of paragneiss and amphibolite at about 5 to 10 kbars for a temperature of 780 to 850 °C followed by melt/solid segregation and fractional crystallization are susceptible to generate the Na- and K-rich series.
U-Pb dating of zircon from a titanite-allanite-bearing pegmatite at 2094.3 ± 8.8 Ma and of apatite from tonalitic-trondhjemitic gneiss, apatite-zircon-bearing pegmatite and granodioritic gneiss at 2094 ± 21 Ma, 2055 ± 20 Ma, and 2041 ± 33 Ma respectively, confirm that partial melting, melt segregation and crystallization-cooling occurred during the Eburnean orogeny.
Based on these data, we propose that (i) titanite-allanite- and apatite-zircon-bearing pegmatites result from syntectonic segregation of residual melt during crystallization of the tonalitic-trondhjemitic gneiss, (ii) garnet-columbite-bearing pegmatites originate from syntectonic melt segregation from the migmatitic paragneiss, and (iii) garnet-REE-bearing pegmatites derive from segregation of a residual melt within the granodioritic gneiss.
It has been reported that persistent cyanide pollution occurs in artisanal small-scale gold mining (ASGM)-affected catchment areas in Burkina Faso. In the present study, the logistic regression ...method was employed to identify the factors that influence the spatial distribution of cyanide pollution as well as to predict the cyanide pollution map risk at catchment level. Soil samples were collected from two ASGM sites in the northern Zougnazagmiline (“North”) site and southern Galgouli (“South”) site parts of Burkina Faso, covering areas of 22km2 and 20km2, respectively. Free cyanide concentration in each sample was measured. It was shown that the spatial distribution of cyanide was solely controlled by the soil type in Zougnazagmiline and both the soil type and electric conductivity in Galgouli. On the other hand, the cyanidation zones within the two catchments were the places where the highest risk of cyanide pollution occurs, with probabilities of 0.8 and 1 in Zougnazagmiline and Galgouli, respectively. >20% of the settled area in the Zougnazagmiline and 5% of that in Galgouli were exposed to cyanide pollution. Logistic regression was able to reliably predict cyanide contamination in areas affected by ASGM. The model could be useful for decision-makers to plan ASGM-site decontamination.
•Soil samples were collected from cyanide-contaminated artisanal gold mining areas.•Free cyanide concentrations in the samples were determined.•The spatial distribution of cyanide was modelled by using logistic regression.•Environmental parameters influencing the spatial distribution of cyanide were identified.•Hazard maps were associated with the spatial distribution of cyanide.
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