Exploring Drivers of Invasiveness of the Plant Species \u3ci\u3eSenna obtusifolia\u3c/i\u3e in Rangelands to Secure Forage Production in West Africa

Rangelands in Sahelian countries are continuously over-grazed decreasing forage resources and causing rapid environmental changes. Senna obtusifolia is a less palatable plant species that becomes increasingly invasive. This research explored drivers of its invasiveness in the perspective to propose solutions to secure forage production in the pastoral reserves. Species composition and herbaceous aboveground biomass were assessed in rangelands with different levels of invasion of Senna obtusifolia along a climatic and land-use pressure gradient. A greenhouse experiment was conducted to test the competitiveness of this species. The development of Senna obtusifolia in rangelands affected significantly forage quantity. Indeed the biomass of the others herbaceous species decreased but not the species richness. The overgrazing of Sahelian rangelands combined to the floristic selection operated by livestock reduced the abundance of fodder species and fostered the expansion of S. obtusifolia. Moreover, S. obtusifolia had a good germination rate with a rapid growth that made it more competitive. Thus, in the interspecific competition experiment, the aboveground biomass of S. obtusifolia was not influenced when associated to legume, grass and perennial grass species respectively. After 3 years of full protection experiment, the abundance of S. obtusifolia decreased, hence its invasiveness in rangelands should be supported by the mixed effect of disturbance factors as grazing and drought that lead several plant species to be vulnerable and favor undesirable species expansion. The control of S. obtusifolia expansion is conditionned by the reformulation of the land management systems and the promotion of sustainable environmental policies

Ethnobotanical study of cowpea (Vigna unguiculata (L.) Walp.) in Senegal

Open Access Article; Published online: 05 Feb 2022Cowpea (Vigna unguiculata) plays a key role in family farming systems in Senegal. It makes an essential contribution to economic, nutritional and food security. Although it is crucial, little is known about how farmers classify the diversity of local varieties or about the social practices associated with them. The aim of this study is to characterize the farming practices associated with growing cowpea in Senegal. Surveys were conducted involving 335 rural farmers living in 37 villages, spread across seven regions that produce cowpea. An average of ten farmers were randomly selected in each village. The results reveal that cowpea is a key feature of cropping systems in the studied area. Our findings highlight the high diversity of local cowpea varieties with 59 local names inventoried. In 75% of cases, the name refers to the seed’s morphology or color. Cowpea production is more diverse in Diourbel and Louga and less diverse in the south. More than half the farmers (57%) acquired their cowpea seeds (early, semi-early and late maturity varieties) outside their village, either from markets, seed suppliers or NGOs. This new understanding of farmers’ expertize in the management of cowpea and its local variability will help to valorize local diversity in breeding programs

Knowledge, practices and beliefs of students regarding health effects of shisha use in Ouagadougou, Burkina Faso: A cross‐sectional study

Background. The tobacco epidemic is one of the biggest public health threats the world has ever faced. Shisha use has recently been gaining increased popularity in many developed and developing countries. Objective. To determine the prevalence of shisha use among students in Ouagadougou, Burkina Faso, and associated knowledge, smoking practices and beliefs about health effects. Method. A total of 443 students were selected for this cross-sectional study, using a stratified sampling method. Data on shisha use, knowledge about shisha, shisha smoking practices, and factors associated with use of shisha were collected via a questionnaire. The association between the independent variables and shisha use was assessed using a χ2 test (p<0.05). Binary logistic regression analysis was used to determine variables that were independently associated with shisha smoking. Results. Of the 421 respondents, 162 (38.5%) indicated that they had smoked shisha; 14.0% were regular smokers. We found that 183 students (43.5%) had poor knowledge about the health effects of shisha. The main reasons for shisha smoking were being in the company of friends who were users (57.4%), the pleasant flavour and fragrance of shisha (25.9%), and fashion (22.2%). Ninety-nine shisha smokers (61.1%) also consumed alcohol. Factors associated with shisha smoking included age <20 years (p<0.001), gender (p=0.034), and educational level of the respondent’s father (p=0.0001) and mother (p=0.0004). Conclusion. We found a relatively high prevalence of shisha smoking among the students, and that 43.5% of them had poor knowledge about its effects on health. Developing surveillance, intervention and regulatory/policy frameworks specific to shisha has become a public health priority

Baseline drivers of lymphatic filariasis in Burkina Faso

Lymphatic filariasis (LF) is a parasitic disease that is endemic throughout sub-Saharan Africa, infecting approximately 40 million people. In Burkina Faso, mass drug administration (MDA) for LF with ivermectin and albendazole has been ongoing since 2001, and by 2006 all endemic health districts were receiving MDA with a therapeutic coverage of at least 65%. As MDA activities scale down, the focus is now on targeting areas where LF transmission persists with alternative elimination strategies. This study explored the relationship between village-level, baseline LF prevalence data collected in 2000 with publicly available meteorological, environmental and demographic variables in order to determine the factors that influence the geographical distribution of the disease. A fitted multiple logistic regression model indicated that the length of the rainy season, variability in normalized difference vegetation index (NDVI) and population density were significantly positively associated with LF prevalence, whereas total annual rainfall, average June-September temperature, mean NDVI, elevation and the area of cotton crops were significantly negatively associated. This model was used to produce a baseline LF risk map for Burkina Faso. An extended model which incorporated potential socio-demographic risk factors also indicated a significant positive relationship between LF prevalence and wealth. In overlaying the baseline LF risk map with the number of MDA rounds, plus an insecticide-treated net (ITN) ownership measure, the central southern area of the country was highlighted as an area where baseline LF prevalence was high and ITN coverage relatively low (&lt;50%), while at least 10 rounds of MDA had been undertaken, suggesting that more concentrated efforts will be needed to eliminate the disease in these areas

Soil mineralogical and nutrient characteristics of forest islands and surrounding ecosystem types in West Africa suggest anthropogenic soil improvement

Published online: 12 May 2023Aims Ecosystem changes in the mesic savannas of West Africa are resulting in the formation of patches of ‘forest islands’ around local communities in an otherwise open savanna landscape. There have been conflicting reports on the origin of these forest islands with a very limited understanding of their biogeochemistry. This study evaluated the soil mineralogical and chemical characteristics of forest islands and their surrounding ecosystems comprising croplands and open savannas in Burkina Faso, Ghana, and Nigeria to provide information on the processes leading to the formation of forest islands. Methods Soil mineralogy was determined using X-ray diffractometry (XRD) while the soil nutrients were analysed with ICP-OES and the other soil chemical properties were determined using standard conventional methodologies. Results Overall, we found that quartz, kaolinite with significant quantities of 2:1 silicate minerals dominated the soil matrix irrespective of land use type. The minerals identified in most of the locations were independent of land use type. This suggests that the forest island formation is not directly related to soil mineralogy. Forest islands showed differences in soil nutrient contents, being richer in exchangeable potassium and dibasic cations than their surrounding savannas and agricultural fields. This superior fertility status of the soils could contribute to the luxuriant growth of the vegetation leading to the development of forest island. The soil nutrient characteristics of the ecosystem types reflect the land use practices with the forest island having higher nutrient and organic carbon contents. Conclusions The study provided insight into how human-originated soil nutrient enhancement has induced forest island establishment in open savanna landscapes

Leveraging human resources for outbreak analysis: lessons from an international collaboration to support the sub-Saharan African COVID-19 response

Emerging infectious diseases are a growing threat in sub-Saharan African countries, but the human and technical capacity to quickly respond to outbreaks remains limited. Here, we describe the experience and lessons learned from a joint project with the WHO Regional Office for Africa (WHO AFRO) to support the sub-Saharan African COVID-19 response. In June 2020, WHO AFRO contracted a number of consultants to reinforce the COVID-19 response in member states by providing actionable epidemiological analysis. Given the urgency of the situation and the magnitude of work required, we recruited a worldwide network of field experts, academics and students in the areas of public health, data science and social science to support the effort. Most analyses were performed on a merged line list of COVID-19 cases using a reverse engineering model (line listing built using data extracted from national situation reports shared by countries with the Regional Office for Africa as per the IHR (2005) obligations). The data analysis platform The Renku Project ( https://renkulab.io ) provided secure data storage and permitted collaborative coding. Over a period of 6&#x2009;months, 63 contributors from 32 nations (including 17 African countries) participated in the project. A total of 45 in-depth country-specific epidemiological reports and data quality reports were prepared for 28 countries. Spatial transmission and mortality risk indices were developed for 23 countries. Text and video-based training modules were developed to integrate and mentor new members. The team also began to develop EpiGraph Hub, a web application that automates the generation of reports similar to those we created, and includes more advanced data analyses features (e.g. mathematical models, geospatial analyses) to deliver real-time, actionable results to decision-makers. Within a short period, we implemented a global collaborative approach to health data management and analyses to advance national responses to health emergencies and outbreaks. The interdisciplinary team, the hands-on training and mentoring, and the participation of local researchers were key to the success of this initiative

How well do coverage surveys and programmatically reported mass drug administration coverage match? Results from 214 mass drug administration campaigns in 15 countries, 2008–2017

Introduction Delivering preventive chemotherapy through mass drug administration (MDA) is a central approach in controlling or eliminating several neglected tropical diseases (NTDs). Treatment coverage, a primary indicator of MDA performance, can be measured through routinely reported programmatic data or population-based coverage evaluation surveys. Reported coverage is often the easiest and least expensive way to estimate coverage; however, it is prone to inaccuracies due to errors in data compilation and imprecise denominators, and in some cases measures treatments offered as opposed to treatments swallowed.Objective Analyses presented here aimed to understand (1) how often coverage calculated using routinely reported data and survey data would lead programme managers to make the same programmatic decisions; (2) the magnitude and direction of the difference between these two estimates, and (3) whether there is meaningful variation by region, age group or country.Methods We analysed and compared reported and surveyed treatment coverage data from 214 MDAs implemented between 2008 and 2017 in 15 countries in Africa, Asia and the Caribbean. Routinely reported treatment coverage was compiled using data reported by national NTD programmes to donors, either directly or via NTD implementing partners, following the implementation of a district-level MDA campaign; coverage was calculated by dividing the number of individuals treated by a population value, which is typically based on national census projections and occasionally community registers. Surveyed treatment coverage came from post-MDA community-based coverage evaluation surveys, which were conducted as per standardised WHO recommended methodology.Results Coverage estimates using routine reporting and surveys gave the same result in terms of whether the minimum coverage threshold was reached in 72% of the MDAs surveyed in the Africa region and in 52% in the Asia region. The reported coverage value was within ±10 percentage points of the surveyed coverage value in 58/124 of the surveyed MDAs in the Africa region and 19/77 in the Asia region. Concordance between routinely reported and surveyed coverage estimates was 64% for the total population and 72% for school-age children. The study data showed variation across countries in the number of surveys conducted as well as the frequency with which there was concordance between the two coverage estimates.Conclusions Programme managers must grapple with making decisions based on imperfect information, balancing needs for accuracy with cost and available capacity. The study shows that for many of the MDAs surveyed, based on the concordance with respect to reaching the minimum coverage thresholds, the routinely reported data were accurate enough to make programmatic decisions. Where coverage surveys do show a need to improve accuracy of routinely reported results, NTD programme managers should use various tools and approaches to strengthen data quality in order to use data for decision-making to achieve NTD control and elimination goals