Central African Region Research Articles

Cancer in the Grand Libreville, Gabon (2013–2017)

BackgroundThe burden of cancer is expected to nearly double in sub-Saharan Africa over the next 20 years. In Gabon, the primary population-based cancer registry to be established is located in the Grand Libreville. This study presents cancer incidence rates covering the first 5-year period of registration in this region. Patients and methods1,549 cancer cases were recorded among residents of the Grand Libreville between 2013 and 2017, 955 (61.6 %) women and 594 (38.3 %) males. ResultsThe age standardized incidence rates (ASR) for all sites were 73.3 per 105 in females and 47.7 per 105 in males, rather similar from those observed in neighbouring countries of central Africa. Breast (ASR 19.0 per 105) and cervical cancers (ASR 16.3 per 105) accounted for half of female cancers. Prostate (ASR 12.0 per 105), liver (ASR 5.1 per 105) and colorectal cancers (ASR of 5.0 per 105) accounted for 41.1 % of male cancers. ConclusionBreast and prostate cancers ranked first in females and males, respectively, even if the incidences appear much lower in comparison with other regional cancer registries rates, implying they may be underestimated. Cancers of the digestive organs were markedly more frequent in men than women, especially for liver, colorectal (and anus) and the mouth and pharynx. The incidence rates of these latter cancers are relatively similar to those of other registries of the central African region. These results may be of importance for implementing more adapted strategies in the battle against cancer.

Impact of fiscal policy shocks on health outcomes in Sub-Saharan Africa: A panel structural VAR approach

This study investigates the impact of fiscal policy shocks on health outcomes in Sub-Saharan Africa (SSA). It is motivated by health systems’ increasing reliance on public funding despite growing macroeconomic uncertainties. This study adopts a regional analysis, sampling five countries with the highest per capita public health expenditure from the Central, Eastern, Southern, and Western African regions. The study employs the panel structural vector autoregression technique and expresses health outcomes as a function of fiscal policy and private health expenditure shocks. The results suggest that fiscal policy shock significantly and positively affects health outcomes in Central and Western Africa. However, health outcomes are resilient to fiscal policy shock in Eastern and Southern regions and to private health expenditure shock in all regions. The study indicates that achieving sustainable improvement in health outcomes in SSA would require policies designed to expand health financing options beyond the traditional public and private funding arrangements.

Internet of Things Adoption in Technology Ecosystems within the Central African Region: The Case of Silicon Mountain

The Internet of Things (IoT) has emerged as a transformative technology with the potential to revolutionize various sectors and industries worldwide. Despite its global significance, the adoption and implementation of IoT technologies in emerging technology ecosystems within the Central African region still need to be studied and explored. This paper presents a case study of the Silicon Mountain technology ecosystem, located in Fako division of the southwest region of Cameroon, focusing on the barriers and challenges to adopting and integrating IoT technologies within this emerging tech ecosystem. Through a survey-based approach, we investigate the factors influencing IoT adoption in the Silicon Mountain tech ecosystem, including technological, economic, social, and regulatory factors. Our study reveals key insights into the current state of IoT adoption, opportunities for growth and innovation, and IoT adoption challenges. Key among the challenges identified for impeding IoT uptake were issues related to standardization and financial resources, labor shortage in the industry, educational and knowledge gaps, market challenges, government policies, security and data privacy concerns, and inadequate power supply. Based on our findings, we provide recommendations for policymakers, industry stakeholders, and academic institutions to promote and facilitate the widespread adoption of IoT technologies in Silicon Mountain and the Central African region at large.

Global, regional, and national impact of air pollution on stroke burden: changing landscape from 1990 to 2021

BackgroundExposure to air pollution contributes to cardiovascular disease-related deaths and morbidity, including stroke. However, few studies have examined the global stroke burden linked to air pollution. This study aimed to evaluate the global stroke morbidity and mortality associated with air pollution from 1990 to 2021.MethodWith the Global Burden of Disease Study (GBD) 2021, the numbers, and age-standardized rates (ASRs) of deaths and disability-adjusted life years (DALYs) for air pollution-related stroke were reported globally. Further subgroup analyses were conducted by age, sex, region and country, and stroke subtypes. A linear regression model explored global temporal trends and a cluster analysis examined temporal trends across GBD regions. To predict trends until 2040, the age-period-cohort (APC) model and the Bayesian age-period-cohort (BAPC) model were applied.ResultsIn 2021, there were 1,989,686 (95% uncertainty interval [95% UI], 1,530,479-2,493,238) deaths and 44,962,167 (95% UI, 35,020,339 − 55,467,024) DALYs due to air pollution-related stroke. The ASRs increased with age, peaking generally over 85 years. Males, the Central African region, and Guinea-Bissau showed higher stroke burdens Intracerebral hemorrhage was the most lethal subtype, with an ASR of 11.69 (95% UI 8.94–14.69) for deaths and 276.93 (95% UI 212.21-344.36) for DALYs. From 1990 to 2021, the crude number of deaths and DALYs increased by 13.4% and 6.3%, respectively, for the global stroke burden but showed a declining trend when age-standardized. Most GBD regions in Asia and Africa experienced an increasing stroke burden linked to air pollution, while Europe and America showed a decreasing trend. Predictions indicated a gradual reduction in ASRs, with higher rates in males from 2020 to 2040.ConclusionsThe global stroke burden associated with air pollution remained significant despite a decreasing trend until 2021. Although future predictions suggested a reduction, the crude counts for stroke burden remained substantial, with significant regional disparities. This warranted the implementation of public health policies and ongoing efforts.

New evidence on adolescent sexual and reproductive health and rights from the West and Central African region.

The African Journal of Reproductive Health is pleased to publish these compendiums of original research in this special edition that document new findings in adolescent sexual and reproductive health and rights from the West and Central African region (WCA). While sub-Saharan Africa has some of the worst indicators of sexual and reproductive health and rights (SRHR) in the world, the indicators are more daunting in the WCA region. To date, the WCA is recognized to have the highest rates of unwanted pregnancy, unsafe abortion, and human immunodeficiency virus (HIV) and other sexually transmissible infections, as well as the lowest contraceptive prevalence rates among adolescents worldwide.1 Despite the high rate of adverse adolescent reproductive health outcomes in WCA, there has been limited documentations of the socio-cultural and economic circumstances that perpetuate these adverse consequences. There have also been no purposefully designed interventions that provide strong scientific evidence for developing strategies to reverse the trend.

Precious and Base Metal Minerals in Black Sands of the Egyptian Mediterranean Coast: Mineralogical and Geochemical Attributes

This paper investigates the mineralogical and geochemical characteristics, as well as the possible sources, of gold, silver, platinum group elements (PGE), copper, and lead found in the beach sands along Egypt’s Mediterranean coast. Using scanning electron microscopy and electron probe micro-analysis, this study determines the morphology and micro-chemistry of separated grains to assess their economic potential and how various minerals respond to different transport distances. The analysis reveals that gold grains are of high purity (94.11 to 98.55 wt.%; average 96 wt.% Au) and are alloyed with Ag (1.28–2.32 wt.%) and Cu (0.16–3.15 wt.%). Two types of gold grains were identified, indicating differences in transport distances. Variations in morphology, surface features, inclusion types, rims, and chemistry of the native metals, including gold grains, suggest differences in composition, weathering degree, transport distance, deposit types, and host rocks. The average Ag concentration in gold grains (1.86 wt.%) suggests a link to mesothermal or supergene deposits. Most silver, copper, and lead grains are spherical, with some variations in shape. Silver grains have 71.66–95.34 wt.% Ag (avg. 82.67 wt.%). Copper grains have 92.54–98.42 wt.% Cu (avg. 94.22 wt.%). Lead grains contain 74.22–84.45 wt.% Pb (avg. 79.26 wt.%). The identified platinum group minerals (PGM) belong to the Pt–Fe alloys and sperrylite, both of which are PPGE-bearing minerals. These metals likely originate from the weathering of upstream Nile tributaries surrounded by igneous and metamorphic rocks from Ethiopian and Central African regions, with a minor contribution from the Egyptian Eastern Desert Mountains.

Snake species assemblages across habitat types in four departments of the Republic of Congo, with emphasis on medically-relevant venomous species

Snakebite is a neglected public health crisis in sub-Saharan Africa. There is a particular lack of data (on snakes and snakebite) from the central African region. This study was conducted in the departments of Likouala, Sangha, Cuvette-Ouest and Kouilou, in the Republic of Congo. The objective was to inventory snakes in the four localities with particular emphasis on medically relevant venomous snakes in order to improve knowledge of snakes in order to minimize the risks of snakebite envenomation to humans. Two methods (active and passive) were used to collect specimens from different habitats. Fifty-one (51)snake specimens including 14 medically relevant snake specimens representing 3 families, 3 subfamilies, 5 genera, and 6 species, in addition to 22 harmless species, were collected. We found a high number of medically important venomous species in Okoyo, Mokéko and Mvouti districts with 3 species each. The highest number of medically important venomous species was recorded in natural forests and human habitations, five and four species respectively. The species obtained (Atheris squamigera, Bitis arietans, Bitis gabonica, Dendroaspis jamesoni, Naja melanoleuca and Toxicodryas blandingii) are medically relevant toxic species according to the WHO classification. Further studies would be necessary to assess the epidemiology of bite risks snakes and educate the public to minimize accidental human-snake contact.

Seroprevalence of human immunodeficiency virus in African blood donors: a systematic review and meta-analysis

In developing countries, the safety of blood transfusions remains an important public health concern as it is associated with a higher risk of transfusion-transmissible infections (TTIs). In this study, we aimed to estimate the seroprevalence of HIV among blood donors in Africa and assess the temporal trends and regional differences within the continent through a systematic review and meta-analysis. Seven electronic databases (PubMed, Web of Science, Cochrane, Scopus, HINARI, Global Index Medicus and Clinical. gov) were searched for relevant studies for our research. We included all primary studies that estimated the seroprevalence of HIV among blood donors in Africa with an age population from 16 to 65 years old, without language restrictions, from inception up to March 1st 2024. The pooled seroprevalence was estimated through the DerSimonian-Laird random effects model. The temporal trends and regional differences were assessed through subgroup and meta-regression analysis. We obtained 122 studies that met our inclusion criteria, comprising 7,814,996 blood donors tested for HIV. Sixty-six percent of the studies were from Western and Eastern Africa. The pooled seroprevalence of HIV among blood donors in Africa was 2.66% (95% CI: 2.17-3.20%; I2=99.80%, p<0.01). The highest prevalence was observed in the Central African region, 3.28% (95% CI: 2.57%-4.06%), followed by the Eastern 3.21% (95% CI: 2.12%-4.52%), and the Western 2.66% (95% CI: 1.93%-3.49%) regions. Lower prevalences were observed in the Northern region, 0.57% (95% CI: 0.0%-2.10%), followed by the Southern African region with 0.45% (95% CI: 0.16%-0.86%). We observed a temporal decreased trend of HIV prevalence. The prevalence of HIV infection among African blood donors remains high and is not homogeneous across the continent. Efficient measures to strengthen HIV testing and prevent HIV transmission through blood transfusion are needed in Africa. Systematic review protocol registration: PROSPERO CRD42023395616. This article was supported by National Funds through FCT - Fundação para a Ciência e a Tecnologia,I.P., within CINTESIS, R&D Unit (reference UIDP/4255/2020).

Utility of plasma anti-gSG6-P1 IgG levels in determining changes in Anopheles gambiae bite rates in a rural area of Cameroon

The applicability of the specific human IgG antibody response to Anopheles gambiae salivary Gland Protein-6 peptide 1 (gSG6-P1 salivary peptide) as a biomarker able to distinguish the level of exposure to mosquito bites according to seasonal variations has not yet been evaluated in Central African regions. The study aimed to provide the first reliable data on the IgG anti-gSG6-P1 response in rural area in Cameroon according to the dry- and rainy-season. Between May and December 2020, dry blood samples were collected from people living in the Bankeng village in the forest area of the Centre region of Cameroon. Malaria infection was determined by thick-blood smear microscopy and multiplex PCR. The level of IgG anti-gSG6-P1 response, was assessed by enzyme-linked immunosorbent assay. Anopheles density and aggressiveness were assessed using human landing catches. The prevalence of malaria infection remains significantly higher in the rainy season than in the dry season (77.57% vs 61.44%; p = 0.0001). The specific anti-gSG6-P1 IgG response could be detected in individuals exposed to few mosquito bites and showed inter-individual heterogeneity even when living in the same exposure area. In both seasons, the level of anti-gSG6-P1 IgG response was not significantly different between Plasmodium infected and non-infected individuals. Mosquito bites were more aggressive in the rainy season compared to the dry season (human biting rate-HBR of 15.05 b/p/n vs 1.5 b/p/n) where mosquito density was very low. Infected mosquitoes were found only during the rainy season (sporozoite rate = 10.63% and entomological inoculation rate-EIR = 1.42 ib/p/n). The level of IgG anti-gSG6-P1 response was significantly higher in the rainy season and correlated with HBR (p ˂ 0.0001). This study highlights the high heterogeneity of individual’s exposure to the Anopheles gambiae s.l vector bites depending on the transmission season in the same area. These findings reinforce the usefulness of the anti-gSG6-P1 IgG response as an accurate immunological biomarker for detecting individual exposure to Anopheles gambiae s.l. bites during the low risk period of malaria transmission in rural areas and for the differentiating the level of exposure to mosquitoes.

Transmission dynamics, complications and mitigation strategies of the current mpox outbreak: A comprehensive review with bibliometric study.

As the mankind counters the ongoing COVID-19 pandemic by the novel severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), it simultaneously witnesses the emergence of mpox virus (MPXV) that signals at global spread and could potentially lead to another pandemic. Although MPXV has existed for more than 50years now with most of the human cases being reported from the endemic West and Central African regions, the disease is recently being reported in non-endemic regions too that affect more than 50 countries. Controlling the spread of MPXV is important due to its potential danger of a global spread, causing severe morbidity and mortality. The article highlights the transmission dynamics, zoonosis potential, complication and mitigation strategies for MPXV infection, and concludes with suggested 'one health' approach for better management, control and prevention. Bibliometric analyses of the data extend the understanding and provide leads on the research trends, the global spread, and the need to revamp the critical research and healthcare interventions. Globally published mpox-related literature does not align well with endemic areas/regions of occurrence which should ideally have been the scenario. Such demographic and geographic gaps between the location of the research work and the endemic epicentres of the disease need to be bridged for greater and effective translation of the research outputs to pubic healthcare systems, it is suggested.

The freedom to love, move and organize

The late Tom Lodge’s magisterial Red Road to Freedom will surely become the standard text on communism in South Africa, definitively re-assessing the sociological development and historiographically-contested political arc of the Communist Party of South Africa (CPSA). The book, nevertheless, is squarely focused on the South African public realm, eliding the important private experiences of individual CPSA members and significant transnational interchanges with the broader Southern and Central African region. Early CPSA leaders were often strikingly restrictive about the kinds of relationships available to members; had a complicated, often hostile, relationship with immigrant workers; and were opposed to organising across colonial borders. For marginalised groups, these examples prompt difficult questions about what ‘freedom’ meant to communists and where the early CPSA’s Red Road was ultimately headed to.

Knowledge, attitude and perception towards COVID-19 among representative educated sub-Saharan Africans: A cross-sectional study during the exponential phase of the pandemic.

Coronavirus disease 2019 (COVID-19) pandemic, caused by the Severe Acute Coronavirus 2 (SARS-CoV-2), is a global health threat with extensive misinformation and conspiracy theories. Therefore, this study investigated the knowledge, attitude and perception of sub-Saharan Africans (SSA) on COVID-19 during the exponential phase of the pandemic. In this cross-sectional survey, self-administered web-based questionnaires were distributed through several online platforms. A total of 1046 respondents from 35 SSA countries completed the survey. The median age was 33 years (18-76 years) and about half (50.5%) of them were males. More than 40% across all socio-demographic categories except the Central African region (21.2%), vocational/secondary education (28.6%), student/unemployed (35.5%), had high COVID-19 knowledge score. Socio-demographic factors and access to information were associated with COVID-19 knowledge. Bivariate analysis revealed that independent variables, including the region of origin, age, gender, education and occupation, were significantly (p < 0.05) associated with COVID-19 knowledge. Multivariate analysis showed that residing in East (odds ratio [OR]: 7.9, 95% confidence interval (CI): 4.7-14, p<0.001), Southern (OR: 3.7, 95% CI: 2.1-6.5, p<0.001) and West (OR: 3.9, 95% CI: 2.9-5.2, p<0.001) Africa was associated with high COVID-19 knowledge level. Apart from East Africa (54.7%), willingness for vaccine acceptance across the other SSA regions was <40%. About 52%, across all socio-demographic categories, were undecided. Knowledge level, region of origin, age, gender, marital status and religion were significantly (p < 0.05) associated with COVID-19 vaccine acceptance. About 67.4% were worried about contracting SARS-CoV-2, while 65.9% indicated they would consult a health professional if exposed. More than one-third of the respondents reported that their governments had taken prompt measures to tackle the pandemic. Despite high COVID-19 knowledge in our study population, most participants were still undecided regarding vaccination, which is critical in eliminating the pandemic. Therefore, extensive, accurate, dynamic and timely education in this aspect is of ultimate priority.

Resisting Material Binaries: Unpacking persisting dichotomies of building materials in Central Africa

The current discourse on African architecture is strongly influenced by social design—a practice for which architecture holds an important role in addressing complex societal questions and problems. The use of “alternative” building materials, as opposed to industrial materials like concrete or steel, is very central within this discourse. However, as this article argues, this strong binary approach to building materials is heavily influenced by colonial and postcolonial logic. To understand this continuity, I will trace some path dependencies visible in the Central African region from the colonial period to the present. In the first section, the material preferences of a Belgian architecture firm working in Rwanda in 2012 are related to the binaries of the architecture firms operating in this region in the 1970s and 1980s. In the second section, I discuss how the strong distinction between so-called “local” and “modern” materials is a remnant of the colonial period. Through an in-depth analysis of the shifting valuations of cement and burnt lime in Central Africa, the article aims to make these colonial categories feel less natural. Building on post-colonial science and technology studies (STS) scholarship, the conclusion proposes an alternative to binary thinking—a conscious material choice that tries to understand building materials as situated processes, allowing to go beyond the industry-driven denominators by which we currently value our building materials.

Challenges to the Implementation of Regional Integration in ECCAS with Respect to the Free Movement of Persons and Goods.

As part of the community’s goals to develop and promote the culture of human integration, the establishment of ECCAS in 1983 was accompanied by an enabling Protocol (Annex VII, ECCAS Treaty) on free movement of persons and goods within the Central African region, with the vision to fully integrate in years to come. The movement of persons and goods without restriction constitute a major lynchpin towards market integration most especially as People are carriers of goods, consumers’ services, technologies, businesses and knowledge and can effectively tear down policy-induced barriers to trade carrying assets. Despite these benefits and mindful of the spirit enshrined in the aforementioned protocol, the mobility of persons and goods within ECCAS remains a challenging venture. This article, therefore, aims at exposing some fundamental challenges that impede the free circulation of goods and nationals of ECCAS’s Member States within the region. Pooling data largely from secondary sources and through a descriptive approach of data analysis, this study argues that the ECCAS’s protocol on free movement of persons and goods is not effectively implemented due to poor infrastructural and communication links within the region; ethnic divide; political instability; the rise of nationalism; hostile relations; rivalry/enmity between central African heads of state; and regular roadblocks within and across national borders. In this guise, it is categorically imperative for ECCAS’s member states to recognize the fact that the above highlighted challenges constitute an indication to deal with them most especially as free movement of persons and goods represents major pillars upon which integration is based.

Mosquito-Borne Arboviruses Occurrence and Distribution in the Last Three Decades in Central Africa: A Systematic Literature Review.

Arboviruses represent a real public health problem globally and in the Central African subregion in particular, which represents a high-risk zone for the emergence and re-emergence of arbovirus outbreaks. Furthermore, an updated review on the current arbovirus burden and associated mosquito vectors is lacking for this region. To contribute to filling this knowledge gap, the current study was designed with the following objectives: (i) to systematically review data on the occurrence and distribution of arboviruses and mosquito fauna; and (ii) to identify potential spillover mosquito species in the Central African region in the last 30 years. A web search enabled the documentation of 2454 articles from different online databases. The preferred reporting items for systematic reviews and meta-analyses (PRISMA) and the quality of reporting of meta-analyses (QUORUM) steps for a systematic review enabled the selection of 164 articles that fulfilled our selection criteria. Of the six arboviruses (dengue virus (DENV), chikungunya virus (CHIKV), yellow fever virus (YFV), Zika virus (ZIKV), Rift Valley fever virus (RVFV), and West Nile virus (WNV)) of public health concern studied, the most frequently reported were chikungunya and dengue. The entomological records showed >248 species of mosquitoes regrouped under 15 genera, with Anopheles (n = 100 species), Culex (n = 56 species), and Aedes (n = 52 species) having high species diversity. Three genera were rarely represented, with only one species included, namely, Orthopodomyia, Lutzia, and Verrallina, but individuals of the genera Toxorhinchites and Finlayas were not identified at the species level. We found that two Aedes species (Ae. aegypti and Ae. albopictus) colonised the same microhabitat and were involved in major epidemics of the six medically important arboviruses, and other less-frequently identified mosquito genera consisted of competent species and were associated with outbreaks of medical and zoonotic arboviruses. The present study reveals a high species richness of competent mosquito vectors that could lead to the spillover of medically important arboviruses in the region. Although epidemiological studies were found, they were not regularly documented, and this also applies to vector competence and transmission studies. Future studies will consider unpublished information in dissertations and technical reports from different countries to allow their information to be more consistent. A regional project, entitled "Ecology of Arboviruses" (EcoVir), is underway in three countries (Gabon, Benin, and Cote d'Ivoire) to generate a more comprehensive epidemiological and entomological data on this topic.

Demands for Intersectoral Actions to Meet Health Challenges in East and Southern Africa and Methods for Their Evaluation

ObjectivesFocusing on the East, Central, and Southern African region, this study examines both regional and country-level initiatives aimed at promoting multisectoral collaboration to improve population health and the methods for their economic evaluation. MethodsWe explored the interventions that necessitate cooperation among policymakers from diverse sectors and the mechanisms that facilitate effective collaboration and coordination across these sectors. To gain insights into the demand for multisectoral collaboration in the East, Central, and Southern African region, we presented 3 country briefs, highlighting policy areas and initiatives that have successfully incorporated health-promoting actions from outside the health sector in Zimbabwe, Uganda, and Malawi. Additionally, we showcased initiatives undertaken by the Ministry of Health in each country to foster coordination with national and international stakeholders, along with existing coordination mechanisms established for intersectoral collaboration. Drawing on these examples, we identified the primary challenges in the economic evaluation of multisectoral programs aimed at improving health in the region. ResultsWe illustrated how decision making in reality differs from the traditional single-sector and single-decision-maker perspective commonly used in cost-effectiveness analyses. To ensure economic evaluations can inform decision making in diverse settings and facilitate regional collaboration, we highlighted 3 fundamental principles: identifying policy objectives, defining the perspective of the analysis, and considering opportunity costs. We emphasized the importance of adopting a flexible and context-specific approach to economic evaluation. ConclusionsThrough this work, we contribute to bridging the gap between theory and practice in the context of intersectoral activities aimed at improving health outcomes.

Whole genome sequencing of outbreak strains from 2017 to 2018 reveals an endemic clade of dengue 1 virus in Cameroon

ABSTRACT Dengue fever is expanding as a global public health threat including countries within Africa. For the past few decades, Cameroon has experienced sporadic cases of arboviral infections including dengue fever. Here, we conducted genomic analyses to investigate the origin and phylogenetic profile of Cameroon DENV-1 outbreak strains and predict the impact of emerging therapeutics on these strains. Bayesian and maximum-likelihood phylogenetic inference approaches were employed in virus evolutionary analyses. An in silico analysis was performed to assess the divergence in immunotherapeutic and vaccine targets in the new genomes. Six complete DENV-1 genomes were generated from 50 samples that met a clinical definition for DENV infection. Phylogenetic analyses revealed that the strains from the current study belong to a sub-lineage of DENV-1 genotype V and form a monophyletic taxon with a 2012 strain from Gabon. The most recent common ancestor (TMRCA) of the Cameroon and Gabon strains was estimated to have existed around 2008. Comparing our sequences to the vaccine strains, 19 and 15 amino acid (aa) substitutions were observed in the immuno-protective prM-E protein segments of the Dengvaxia® and TetraVax-DV-TV003 vaccines, respectively. Epitope mapping revealed mismatches in aa residues at positions E155 and E161 located in the epitope of the human anti-DENV-1 monoclonal antibody HMAb 1F4. The new DENV strains constitute a conserved genomic pool of viruses endemic to the Central African region that needs prospective monitoring to track local viral evolution. Further work is needed to ascertain the performance of emerging therapeutics in DENV strains from the African region.

Small scale agriculture continues to drive deforestation and degradation in fragmented forests in the Congo Basin (2015–2020)

The Central African region hosts the largest continuous tract of forest in Africa, regulating global climate while providing essential resources and livelihoods for millions of people and harbouring extensive biodiversity. Extractive industries, infrastructure development and industrial agriculture have often been cited as major threats to these forests and are expected to increase. A regional collaborative effort has produced the first systematically validated remote sensing assessment of deforestation and degradation drivers in six central African countries for the 2015–2020 time period. Multiple, overlapping drivers are assessed through visual interpretation and show that the rural complex, a combination of small-scale agriculture, villages, and roads contributes to the majority of observed deforestation and degradation. Industrial drivers such as mining and forestry are less common, although their impacts on carbon and biodiversity could be more permanent and significant than informal activities. Artisanal forestry is the only driver that is observed to be consistently increasing over the study period. Our assessment produces information relevant for climate change mitigation and land use planning which requires detailed information on multiple direct drivers to target specific activities and investments.

Pesticide Usage in Pest Management by Vegetable Producers in the Foumbot Production Basin of the Western Highlands (Cameroon)

Purpose: Cameroon is the food basket of the Central African Region in terms of food production and a significant proportion of her population depends on the production of fruits and vegetables for livelihood. The Western Highlands of Cameroon is known for its high agricultural output, especially in the domain of market gardening. The Foumbot Production Basin in the Western Highlands of Cameroon is noted for its high agricultural output, especially in the domain of market gardening. Produce originating from this area is consumed throughout the nation, especially in the Southern Regions of Cameroon and also exported to neighbouring countries like Gabon, Equatorial Guinea and Central African Republic. This study therefore sought to find out how pesticides are being employed in the production of these crops (mostly fruits and leafy vegetables, of short growing cycles) in the Foumbot Production Basin of the Western Highlands of Cameroon. &#x0D; Methodology: A survey was conducted in which a well-developed questionnaire containing both closed multiple-choice and open-ended questions, was established to collect important information related to the topic from the market gardeners in the Foumbot Production Basin. A total of 100 market gardeners were interviewed. Data was analyzed using descriptive statistics. The data allowed us to assess the pesticide use practices of tomato growers by having a clear idea on demographic social characteristics (sex, level of education, age, and marital status), agronomic practices (cropping season and cropping system), application of pesticides (types of pesticides used, source of information’s relating to the use of pesticides, the moment of application, reaction following the ineffectiveness of the product, respect pre-harvest intervals, knowledge of the presence of residues in the fruits, health effects, wearing of PPE and disposal of empty packaging). &#x0D; Findings: It was observed that a majority of the gardeners were males with mostly secondary education. Many of the gardeners did not disposed their empty pesticide containers properly while a majority did not use personal protective equipment during application. Up to 93% of producers do not respect or ignore the pre-harvest interval. Harvest was determined by the availability of buyers of the crop, irrespective of the last time it was sprayed. This is attributed to the complete absence of extension services and training. &#x0D; Unique Contribution to Theory, Practice and Policy: This information can be used to develop a training programme on pest management especially on pesticide use in the Foumbot Production Basin.

Trends and seasonal variability in ammonia across major biomes in western and central Africa inferred from long-term series of ground-based and satellite measurements

Abstract. Ammonia (NH3) is the most abundant alkaline component in the atmosphere. Changes in NH3 concentrations have important implications for atmospheric chemistry, air quality, and ecosystem integrity. We present a long-term ammonia (NH3) assessment in the western and central African regions within the framework of the International Network to study Deposition and Atmospheric chemistry in Africa (INDAAF) programme. We analyse seasonal variations and trends in NH3 concentrations and total column densities along an African ecosystem transect spanning dry savannas in Banizoumbou, Niger, and Katibougou, Mali; wet savannas in Djougou, Benin, and Lamto, Côte d'Ivoire; and forests in Bomassa, Republic of the Congo, and Zoétélé, Cameroon. We use a 21-year record of observations (1998–2018) from INDAAF passive samplers and an 11-year record of observations (2008–2018) of atmospheric vertical column densities from the Infrared Atmospheric Sounding Interferometer (IASI) to evaluate NH3 ground-based concentrations and total column densities, respectively. Climatic data (air temperature, rainfall amount, and leaf area index), as well as ammonia emission data of biomass combustion from the fourth version of the Global Fire Emissions Database (GFED4) and anthropogenic sources from the Community Emissions Data System (CEDS), were compared with total NH3 concentrations and total columns over the same periods. Annual mean ground-based NH3 concentrations are around 5.7–5.8 ppb in dry savannas, 3.5–4.7 ppb in wet savannas, and 3.4–5.6 ppb in forests. Annual IASI NH3 total column densities are 10.0–10.7 × 1015 molec. cm−2 in dry savanna, 16.0–20.9 × 1015 molec. cm−2 in wet savanna, and 12.4–13.8 × 1015 molec. cm−2 in forest stations. Non-parametric statistical Mann–Kendall trend tests applied to annual data show that ground-based NH3 concentrations increase at Bomassa (+2.56 % yr−1) but decrease at Zoétélé (−2.95 % yr−1) over the 21-year period. The 11-year period of IASI NH3 total column density measurements show yearly increasing trends at Katibougou (+3.46 % yr−1), Djougou (+2.24 % yr−1), and Zoétélé (+3.42 % yr−1). From the outcome of our investigation, we conclude that air temperature, leaf area index, and rainfall combined with biomass burning, agricultural, and residential activities are the key drivers of atmospheric NH3 in the INDAAF stations. The results also show that the drivers of trends are (1) agriculture in the dry savanna of Katibougou; (2) air temperature and agriculture in the wet savanna of Djougou and Lamto; and (3) leaf area index, air temperature, residential, and agriculture in the forest of Bomassa.