Central Africa Research Articles

The political ecology of cocoa agroforestry and implications for equitable land use in rural Ghana

AbstractThe relevance of cocoa agroforestry is widely discussed in debates on sustainability transition in cocoa, especially in the context of ending hunger and poverty among cocoa farmers. Whereas this has led to multiple cocoa agroforestry investments by NGOs, governments, and cocoa and chocolate companies in West and Central Africa, a notable gap exists in the literature on how these interventions respond to the needs of cocoa farmers who are typically framed as the primary target of equity in cocoa sustainability discussions. This paper contributes to bridging this gap by analyzing equity in implementing various cocoa agroforestry projects by different actors in Ghana’s Juabeso-Bia Landscape (JBL). I find that the ongoing cocoa agroforestry initiatives may be broadly characterized as renovative or additive in terms of how they (re)shape the various components on cocoa farms. Yet, they are all designed to primarily enhance cocoa productivity even when seasonal food insecurity is one of the most pressing challenges among cocoa farmers in the JBL. The persistent neglect of food in cocoa production risks leaving poverty and hunger in cocoa households unaddressed. Additionally, it increases cocoa households' predisposition to forest conversion, making current forms of cocoa agroforestry an indirect driver of deforestation in the landscape. To transform the current situation, policymakers and scholars must reflexively integrate household food security in designing cocoa agroforestry, prioritizing farmers’ involvement in dynamic agroforestry technologies that contribute directly to local food access over time. This contrasts the current policy and practice of cocoa agroforestry, focused on maintaining a prescribed number of shade trees on new or existing cocoa farms but highly likely to engender significantly greater inequity in the cocoa sector.

A global attribution analysis of increasing risk of successive runoff-heat extreme events driven by anthropogenic forcing

The successive runoff-heat extreme (SRHE) events, defined as the occurrence of an extreme runoff event followed by a heatwave event, have become more frequent under recent global warming. However, the impact of anthropogenic climate change (ACC) on global changes in SRHE characteristics during the past decades remains unclear. Here, we evaluate the impact of ACC on SRHE frequency and characteristics during 1950–2014, based on the daily maximum and minimum temperature and total runoff data simulated by five global climate models (GCMs) from the Coupled Model Intercomparison Project Phase 6 (CMIP6) under the “anthropogenic and natural both (ALL)” and “natural only (NAT)” experiments. Attribution of SRHE changes with different durations and intervals between extreme runoff and heatwave (IRHs) is achieved by using the fraction attributable risk (FAR) method. Results indicate that ACC exacerbates SRHE occurrence for most global regions, especially in the Southern Hemisphere (> 60 % increase in probability), but the spatial variability of this impact decreases over time. The globally-average probability of SRHE occurrence due to ACC has increased significantly by 40 % during 1971–2014 (∼10 %/decade), and the probability of SRHE with the short IRHs and long duration tends to be larger than other types of SRHE. ACC also prolongs the duration of SRHE in most global regions, with an increase of 1–4.5 folds in northern South America, central Africa, and southeastern Asia during 1950–2014. Partial correlation analysis indicates that the intensification of heatwave due to ACC contributes more than that of extreme runoff to SRHE occurrence in nearly all global regions, particularly in the Southern Hemisphere.

Quantification of eosinophil densities in the oesophagus, stomach and small bowel of adults: A review of endoscopic and surgical specimens with normal histology, Free State Province, South Africa.

Studies defining eosinophil densities in the gastrointestinal tract (GIT) are limited. To assess whether eosinophils are pathologically infiltrating the GIT, it is important to evaluate eosinophil densities for specific populations. A retrospective, quantitative, comparative study was conducted to determine the number of eosinophils in the oesophagus, stomach and small bowel of patients in central South Africa and to investigate whether a statistically significant difference occurred between ethnic and gender groups. In total, 309 histological sections from the oesophagus, gastric corpus, gastric antrum and small intestine were sampled from male and female, African and Caucasian patients. Histology reports and review of the slides confirmed the absence of histological abnormality. The number of eosinophils in the epithelium and lamina propria were manually quantified. The eosinophil values across gender, ethnicity and location were 0-2.0/mm² for the oesophagus, 0-53.0/mm² for the gastric corpus and 7.1-115.3/mm² for the small intestine. Regarding the gastric antrum, African and Caucasian females had eosinophil values of 1.0-35.7/mm² and 0-22.4/mm², respectively. Males had an eosinophil density of 0-31.6/mm² in the gastric antrum. The eosinophil values in the oesophagus, gastric corpus and small bowel were not significantly different between genders and ethnic groups. The only site where ethnicity influenced the number of eosinophils was the gastric antrum, a discrepancy that cannot be explained. To the authors' knowledge, this is the first report on the eosinophil densities in the oesophagus, stomach and small bowel of adults in South Africa.

Focal spleen lesions in loiasis: A pilot study in Gabon.

Infection with the filarial nematode Loa loa, endemic in Central and Western Africa, has been associated with increased morbidity and mortality. A number of reports described the presence of spleen nodules, originating from degenerating microfilariae, in humans and animals infected with L. loa. The long-term consequences of this process on individuals chronically exposed to infection in terms of spleen function and possible link with excess mortality are unknown. The aim of this study was to evaluate the prevalence of focal spleen lesions, their evolution over time, and markers of spleen function, in individuals with L. loa infection living in highly endemic areas of Gabon. This was a cross-sectional study followed by a longitudinal study of the subset of individuals with spleen nodules. Two hundred sixteen participants from Ngounié and Moyen-Ogooué provinces of Gabon, reporting a history of eyeworm migration and/or Calabar swelling, were included. Participants were categorized into infected microfilaraemic with low (N = 74) and high (N = 10) microfilaraemia, and symptomatic amicrofilaraemic (N = 132), based on blood microscopy. Howell-Jolly bodies in erythrocytes, as indirect marker of spleen functional impairment, were within normal ranges. On ultrasound, no evident signs of spleen fibrosis or hypotrophy were observed. Multiple spleen hypoechoic centimetric macronodules were observed in 3/216 participants (1.4%), all with microfilaraemic L. loa infection (3.4% of microfilaraemics); macrondules disappeared at the 6-months follow-up examination in 2/3 individuals. Spleen hypoechoic micronodules, persisting at the 6-months follow-up, were detected in 3/216 participants (1.4%), who were all amicrofilaraemic. Transitory spleen macronodules are present in a small but consistent proportion of individuals with microfilaraemic loiasis, appearing a rather benign phenomenon in terms of impact on spleen morphology and function. Their occurrence should be taken into consideration to avoid misdiagnosis and mistreatment. Prevalence and significance of spleen micronodular ultrasound patterns in the general population would be also worth evaluating.

Rheumatic valve disease in children still a burden in sub-Saharan Africa: Diagnostic, therapeutic and prognostic aspects in two hospitals in Central Africa subregion

Rheumatic valve disease in children still a burden in sub-Saharan Africa: Diagnostic, therapeutic and prognostic aspects in two hospitals in Central Africa subregion

Climate change could fuel urinary schistosomiasis transmission in Africa and Europe.

The freshwater snail Bulinus truncatus is an important intermediate host for trematode parasites causing urogenital schistosomiasis, a tropical disease affecting over 150 million people. Despite its medical importance, uncertainty remains about its global distribution and the potential impacts of climate change on its future spread. Here, we investigate the distribution of B. truncatus, combining the outputs of correlative and mechanistic modelling methods to fully capitalize on both experimental and occurrence data of the species and to create a more reliable distribution forecast than ever constructed. We constructed ensemble correlative species distribution models using 273 occurrence points collected from different sources and a combination of climatic and (bio)physical environmental variables. Additionally, a mechanistic thermal suitability model was constructed, parameterized by recent life-history data obtained through extensive lab-based snail-temperature experiments and supplemented with an extensive literature review. Our findings reveal that the current suitable habitat for B. truncatus encompasses the Sahel region, the Middle East, and the Mediterranean segment of Africa, stretching from Southern Europe to Mozambique. Regions identified as suitable by both methods generally coincide with areas exhibiting high urogenital schistosomiasis prevalence. Model projections into the future suggest an overall net increase in suitable area of up to 17%. New suitable habitat is in Southern Europe, the Middle East, and large parts of Central Africa, while suitable habitat will be lost in the Sahel region. The change in snail habitat suitability may substantially increase the risk of urogenital schistosomiasis transmission in parts of Africa and Southern Europe while reducing it in the Sahel region.

Oral Bible Translation as a Means of Enhancing Bible Engagement in Oral Communities: A Survey of Rural Congregations of the Church of Central Africa Presbyterian, Nkhoma Synod, in Malawi

More than one hundred years of Bible translation in Malawi with a primary focus on the production of written versions has left behind those who have an oral orientation, negatively affecting Bible engagement in most rural communities. This study reports on a survey that was done in rural congregations of the Church of Central Africa Presbyterian, Nkhoma Synod, in Malawi, on the levels of Bible engagement and the viability of oral Bible translation. Before presenting the results of the survey, the study appraises the history of Bible translation in Malawi for the purpose of highlighting the communication gap left by written Bible translations. A discussion of both scholarly and biblical materials establishes the need for oral Bible translation.

A scoping review of stroke registers in Sub-Saharan Africa.

Stroke registers are recommended as a key priority by the Lancet Neurology World Stroke Organization Commission for Stroke, 2023, and the African Stroke Leaders' Summit, 2022. This scoping review aims to map where stroke registers have been implemented in Sub-Saharan Africa (SSA). The article then compares and critiques the methods and definitions used and summarizes key results from the registers. The scoping review searched EMBASE, MEDLINE, and CABI Global Health databases and included all studies with a prospective longitudinal design in SSA, where adult acute stroke was the primary condition studied. Articles were screened against inclusion and exclusion criteria independently by two authors. We identified 42 unique stroke registers from 48 individual studies. The registers were located in 19 countries, with 19 from East Africa, 15 West Africa, 6 Central Africa, and 2 from Southern Africa. Cumulatively, the registers recruited 12,345 participants with stroke, the median number of participants was 183 (interquartile range (IQR): 121-312), and the range was 50-1018. Only one study was a population-based register, and 41 were hospital-based registers. Of the hospital-based registers, 29 were single site, 10 were conducted at two sites, and 2 at three sites. Twenty-three (54.7%) of the registers were located in the capital city of their respective country, and only one of the hospital-based registers was in a self-described rural area. Length of recruitment ranged from 4 months to 6 years; the median length of recruitment was 12 months. Methodology and definitions were heterogenous between the registers. Only seven (19.4%) registers referenced the WHO STEPwise approach to implementing stroke registers. Twenty-seven (64.3%) registers used the WHO definition of stroke. The mean neuroimaging rate was 84%, and ranged from 0% to 100%. Stroke severity was measured using the National Institute of Health Stroke Scale (NIHSS) in 22 (52.4%) registers, four registers used the Glasgow Coma Scale (GCS), two registers used the miniNIHSS, one used the Scandinavian Stroke Scale, one modified Rankin Scale (mRS), and 11 registers did not report a stroke severity measure. Seventeen (40.5%) registers used the mRS to measure function, six registers used Barthel Index alone, and three registers used both mRS and Barthel Index. Only two registers included a quality-of-life measure, the EQ-5D. Eight registers included a quality-of-care measure, and 26 (61.9%) registers recorded socioeconomic status or a socioeconomic status proxy, most frequently educational attainment. This scoping review found high heterogeneity of methods and definitions used by stroke registers, with low uptake of the WHO stepwise method of stroke surveillance. A drive to standardize methodology would improve the comparability of stroke data in SSA. The shared use of educational attainment by registers in our review may enable future meta-analyses of inequities in stroke in SSA. Incorporating health-related quality-of-life measures, such as EQ-5D, into stroke registers should be encouraged, bringing a patient perspective, and allow the estimation of quality-adjusted life years lost to stroke. Agreement on a standardized register methodology or further promotion and uptake of the WHO stepwise method is essential to produce comparable data to improve stroke prevention and care.

Ant-following behavior is correlated with plumage traits in African understory birds

Ant-following behavior is a common phenomenon in birds of Neotropical and Afrotropical rainforests but yet little is known from Central Africa. We here report on the phenomenon in lowland rainforest in Cameroon, quantifying the strength of the interaction of different ant-following bird species with driver ants and test the hypothesis that higher levels of specialization in ant-following behavior are associated with dominance or aggression-dependent plumage and other morphological traits. Flock size varied between 1 and 11 individuals with a mean size of 5.34 ± 2.68 (mean ± SD) individuals occurring at the same time. The maximum number of species present during one raid observed was ten, whereas the minimum number was four with an overall species richness of 6.89 ± 2.1 species. The 21 attending bird species strongly varied in the degree of ant-following behavior. In an interspecific comparison, plumage traits such as the presence of a colored crown, eyespots, and bare skin around the eye, in combination with metatarsus length and weight, were significantly correlated with ant-following behavior. These results suggest that—in size and identity of species—ant-following bird assemblages in Central Africa are similar to those reported from East Africa. They also suggest that ant following favors the selection of traits that signal dominance in interactions between individuals struggling for valuable food resources in the forest understory.

Therapeutic Potential of Cornus Genus: Navigating Phytochemistry, Pharmacology, Clinical Studies, and Advanced Delivery Approaches.

The genus Cornus (Cornaceae) plants are widely distributed in Europe, southwest Asia, North America, and the mountains of Central America, South America, and East Africa. Cornus plants exhibit antimicrobial, antioxidative, antiproliferative, cytotoxic, antidiabetic, anti-inflammatory, neuroprotective and immunomodulatory activities. These plants are exploited to possess various phytoconstituents such as triterpenoids, iridoids, anthocyanins, tannins and flavonoids. Pharmacological research and clinical investigations on various Cornus species have advanced significantly in recent years. Over the past few decades, a significant amount of focus has also been made into developing new delivery systems for Cornus mas and Cornus officinalis. This review focuses on the morphological traits, ethnopharmacology, phytochemistry, pharmacological activities and clinical studies on extracts and active constituents from plants of Cornus genus. The review also highlights recent novel delivery systems for Cornus mas and Cornus officinalis extractsto promote sustained and targeted delivery in diverse disorders. The overwhelming body of research supports the idea that plants from the genus Cornus have therapeutic potentialand can be investigated in the future for treatingseveral ailments.

New okra genotypes for the management of aphids (Hemiptera: Aphididae) in the diverse ecological landscapes of Central Africa.

Various aphid species, including Aphis gossypii Glover (Hemiptera: Aphididae), are considered important pests of okra and other vegetables. Previous studies under 1 environment in Cameroon, Central Africa, had found multiple okra genotypes with resistance to A. gossypii. However, the stability and yield performance of the "resistant" genotypes across different environments were unknown. Ten previously identified aphid-resistant okra genotypes along with 1 commercial variety and a local landrace (specific to a given location) were compared during 2 seasons in replicated trials in 4 agro-ecological zones of Cameroon that also represent large areas of Central Africa. Aphid populations and okra yield parameters were evaluated. Breeding values were predicted using a linear mixed model for all data, and genotypes by location interactions were identified. The area under the infestation pressure curve (AUIPC) was calculated using aphid count data and subjected to resistance analysis. The Local-the most susceptible with the highest breeding value (+2.33)-and VI060794-one of the moderately resistant-genotypes had the highest yield per hectare. The only resistant genotype VI036213 had the lowest breeding value (-2.20). Genotype × location interactions were significant for yield, pod width, and plant height, while location variance was significant for all parameters evaluated. When considering that higher aphid densities could lead to greater pesticide use and, therefore higher production and environmental costs, the high-yielding VI060794-with moderate aphid resistance across multiple environments-presents an alternative or substitute for local landraces across multiple agro-ecologies of Cameroon and (by extension) Central Africa.

African Women in Neurosurgery: An Exploration of Historical Perspectives, Current Realities, and Future Prospects

Gender disparities remain a significant issue, particularly impacting African women in the field of neurosurgery. Databases, articles, and perspectives were reviewed to identify challenges faced by African Women in Neurosurgery (AWIN), and explore solutions for recruitment, retention, and career advancement of AWIN. In 1982, Africa saw its first female neurosurgeon, with the first female president of the World Federation of Neurosurgical Societies appointed 4 null decades later. Presently, the continent hosts 245 female neurosurgeons, with North Africa comprising the majority at 76.3%, with Algeria notably contributing 72.2% of this total. Southern Africa contributes 7.8%, while West Africa, East Africa, and Central Africa contribute 6.5%, 6.1%, and 3.3%, respectively. Thirteen countries lack neurosurgeons entirely and 30 out of the 54 African nations face shortages of female neurosurgeons, with distributions as follows: North Africa (1-country), Southern Africa (6-countries), West Africa (8-countries), East Africa (9-countries), and Central Africa (6-countries). Our analysis mapped the distribution of 245 AWIN across the African regions and examined the professional trajectories and achievements of 17 pioneering AWIN. Additionally, we compiled registries for: 1) 76 neurosurgical training programs across 26 African countries, 2) organizations tackling gender disparities in neurosurgery, and 3) recommendations to promote AWIN across governmental, community, and academic spheres. To boost AWIN representation in neurosurgery, concerted and comprehensive efforts are vital. Collaboration among medical schools, training programs, and governments is key to fostering diversity and inclusivity in African neurosurgical settings.

A system dynamics modelling assessment of water-energy-food resource demand futures at the city scale: Goma, Democratic Republic of Congo

Understanding future demands of water, energy, and food (WEF) resources is essential to achieve sustainable management of these resources. Based on a survey of 90 households, this study provides an analysis of household water, energy, and food security for the city of Goma, Democratic Republic of Congo, where there is a lack of any such assessment. Water supply is largely unimproved. Electricity supply is fairly reliable in some parts of the city, but not others. Most residents rely on charcoal burning for food preparation. Dietary Diversity Scores are low indicating stable, but low food security. Data collected were used to develop an integrated WEF system dynamics model that was applied to simulate household-level resource demand. To assess future resources demand, four scenarios developed by the Global Scenario Group were simulated. Findings reveal that the 'Great Transition' scenario exerts lower impact on resources demand, representing the most likely trajectory to achieve sustainable socio-economic development and management. However, achieving the conditions required for a ‘Great Transition’ could be challenging in Goma, which is characterised by low incomes, poor access to resources, and the threat of armed conflict. To achieve greater efficiency in resources utilisation and to prepare for the future, a number of recommendations are made, including energy supply diversification, altered agricultural practices to diversify diets, and expansion and improvement of water supply infrastructure. This work provides a basis for similar assessments in DRC and central Africa, highlighting the need for integrated resources management and assessment for regional opportunities toward sustainable development.

Health Implications of Volcanic Ash and Gases from Eruptions at Mount Nyiragongo and Mount Cameroon, Central Africa

Health Implications of Volcanic Ash and Gases from Eruptions at Mount Nyiragongo and Mount Cameroon, Central Africa

Functionality of water supply handpumps in Cameroon (Central Africa)

Functionality of water supply handpumps in Cameroon (Central Africa)

Nationwide Inventory of Mosquitoes and the Distribution of Invasive Aedes (Stegomyia) albopictus (Skuse, 1894) on the Islands of Sao Tome and Principe in Central Africa.

Aedes albopictus (Skuse, 1894), a mosquito originating in Asia, has been introduced to Africa since the 2000s. The mosquito is not only a nuisance but is capable of transmitting various arboviruses. The current study summarized our entomological surveys in the Democratic Republic of Sao Tome and Principe during 2000 to 2016. Adult mosquitoes were collected by sweep nets, human landing catches, and Centers for Disease Control (CDC) light traps, and the immatures were collected from water-filled habitats at 15 sentinel sites and reared to adulthood. Species identification was performed based on morphologic characteristics. Fragments of the cytochrome C oxidase subunit I (COI) and the Wolbachia surface protein (wsp) genes were amplified for mosquitoes collected in Principe. New records of four mosquito species were reported. Aedes albopictus was identified in 2015. The larvae were found distributed over the nation and were predominately in artificial water-holding containers (488/2698, 18.1%). The highest positive rate was observed in used tires in Príncipe (114/250, 45.6%). Mitochondrial DNA analysis revealed low genetic diversity among the invasive populations, but all tested specimens were superinfected by Wolbachia. The ability of Ae. albopictus to adapt to new environments and its involvement in disease transmission make the surveillance and control of this species particularly important.

First Detection of Antibodies Specific to Crimean-Congo Hemorrhagic Fever Virus in Rural Populations of Gabon.

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne viral disease with a mortality rate reaching up to 40% in humans. Currently, CCHF affects three continents: Asia, Europe, and Africa. An increase in confirmed cases in Africa has been observed since 2000. In Central Africa, several countries have reported the circulation of CCHV virus (CCHFV). However, in Gabon, there is a lack of recent data on the circulation of the virus in the Gabonese population. To provide an overview of the epidemiological situation in Gabon, we tested 3,081 human serum samples collected between 2005 and 2008 in villages throughout the country for anti-CCHFV antibodies. Using a double-antigen ELISA kit, our study found 15/3,081 samples positive for CCHFV. These positive samples were also tested using the Blackbox CCHFV IgG kit and the Luminex technique. These analyses confirmed seven and four positives for the Blackbox CCHFV IgG kit and the Luminex technique, respectively. This study suggests low circulation of CCHFV in the rural human population of Gabon. Competent authorities must survey CCHFV to identify and prevent clinical cases in the human population.

Recurring Transient Tooth Pain as Newly Described Symptom of Migratory Loiasis: A Mixed-Methods Study in Rural Gabon.

Loiasis, a filarial pathogen exclusively endemic in central and western Africa, causes a wide spectrum of symptoms. Understanding the breadth of its clinical manifestations is of importance for adequate patient care and to understand its disease burden. Recurring transient pain in the oral cavity was reported as a self-perceived symptom of loiasis in in-depth interviews of patients in a high transmission region in Gabon. Pain was described as stabbing in character and transient for a few days in its temporal course. A quantitative epidemiological survey indicated that transient tooth pain was experienced by 22% of patients infected with Loa loa. Among those individuals, it was exclusively reported by patients suffering from migratory loiasis (24%). Similar findings have been previously described for other filarial pathogens, indicating that transient swellings of the periodontium and the soft tissue of the oral cavity may explain this symptom reported by patients with migratory loiasis.

Trends in three malnutrition factors in the global burden of disease: iodine deficiency, vitamin A deficiency, and protein-energy malnutrition (1990-2019).

Vitamin A deficiency, iodine deficiency, and protein-energy malnutrition are prevalent malnutrition issues that disproportionately affect low-income countries and pose significant risks to the health and development of children and adolescents. This study offers a detailed examination of these deficiencies' prevalence trends and gender and regional variations using Global Burden of Disease Study data from 1990 to 2019. It also assesses the specific impact on various age groups, providing essential insights for targeted health interventions and policy-making. Data spanning from 1990 to 2019 on Vitamin A deficiency, iodine deficiency, and protein-energy malnutrition were extracted from the 2019 Global Burden of Disease Study. Age-Standardized Incidence Rates (ASR) were computed by gender, region, and etiology, utilizing the estimated annual percentage change (EAPC) to assess temporal trends. In 2019, Central Sub-Saharan Africa had the highest prevalence of Vitamin A deficiency, particularly among males, and iodine deficiency peaked in the same region for both genders. South Asia had the highest incidence of protein-energy malnutrition for both genders. Regions with a low Socio-Demographic Index (SDI) showed lower ASR for these deficiencies. Notably, Cameroon, Equatorial Guinea, and Maldives recorded the highest ASR for vitamin A deficiency, iodine deficiency, and protein-energy malnutrition, respectively. The declining ASR trend for vitamin A deficiency, especially among males, suggests effective interventions. East Asia saw a significant increase in iodine deficiency ASR from 1990 to 2019, particularly among women, requiring targeted interventions. The rising ASR of protein-energy malnutrition in several regions, especially among men, raises concerns. Vitamin A deficiency primarily affected children and adolescents, iodine deficiency predominantly impacted adolescents and young adults, and protein-energy malnutrition was chiefly observed among children under 5 years old. These findings underscore the necessity for tailored interventions considering age-specific nutritional needs and challenges.

The Continuum of Violence and Interstices in the Journeys and Bodies of Women on the Move From West Africa.

On the migration route from Western and Central Africa to Europe, aggression toward women's bodies has played a prominent role. In this study, we analyze this route as a continuum of violence and also study the interstices to confront it. Using a biographical narrative methodology, we analyze the narratives of 52 migrant women, through life stories or creative narrative workshops carried out in Mali, Morocco, and Spain. The results allow us to systematize the continuum of violence that the women report, understood as a pedagogy of cruelty but also the possible spaces to build a safe landscape.