Search Results (103)

Flooding is one of Africa’s most impactful natural disasters, significantly affecting human lives, infrastructure, and economies. This study examines the spatial and temporal distribution of historical flood events across the continent from 1927 to 2020, with a focus on fatalities, affected populations, and economic damage. Data from the Emergency Events Database (EM-DAT), the fifth generation of bias-corrected European Centre for Medium-Range Weather Forecasts Reanalysis (ERA5), and the Climate Hazards Group InfraRed Precipitation with Stations (CHIRPS) observational datasets were used to calculate extreme precipitation indices—Consecutive Wet Days (CWD), annual precipitation on very wet days (R95PTOT), and Annual Maximum Precipitation (AMP). Spatial analysis tools and the Mann–Kendall test were used to assess trends in flood occurrences, while Pearson correlation analysis identified key meteorological drivers across 16 African capital cities for 1981–2019. A flood frequency analysis was conducted using Weibull, Gamma, Lognormal, Gumbel, and Logistic probability distribution models to compute flood return periods for up to 100 years. Results reveal a significant upward trend with a slope above 0.50 floods per year in flood frequency and impact over the period, particularly in regions such as West Africa (Nigeria, Ghana), East Africa (Ethiopia, Kenya, Tanzania), North Africa (Algeria, Morocco), Central Africa (Angola, Democratic Republic of Congo), and Southern Africa (Mozambique, Malawi, South Africa). Positive trends (at 99% significance level with slopes ranging between 0.50 and 0.60 floods per year) were observed in flood-related fatalities, affected populations, and economic damage across Regional Economic Communities (RECs), individual countries, and cities of Africa. The CWD, R95PTOT, and AMP indices emerged as reliable predictors of flood events, while non-stationary return periods exhibited low uncertainties for events within 20 years. These findings underscore the urgency of implementing robust flood disaster management strategies, enhancing flood forecasting systems, and designing resilient infrastructure to mitigate growing flood risks in Africa’s rapidly changing climate. Full article

The emergence of high-threat pathogens—such as Ebola, Lassa fever, and most recently SARS-CoV-2—has highlighted critical weaknesses in global surveillance systems, particularly in resource-limited settings where many zoonotic spillovers originate. Despite the World Health Organization’s (WHO) prioritization of these diseases for research and development (R&D), the current surveillance infrastructures in these regions remain under-resourced, fragmented, and often reactive rather than anticipatory. This narrative review explored the literature and structured relevant findings in three key dimensions: (i) the structural and operational limitations of existing surveillance systems for the WHO priority diseases in resource-limited settings including challenges in data integration, laboratory capacity, workforce, and community engagement; (ii) how these surveillance gaps could delay detection and hinder the response to future emerging threats, particularly a hypothetical but inevitable Disease X; and (iii) innovative and context-adapted strategies to strengthen epidemic intelligence including integrated One Health surveillance, digital and genomic tools, participatory approaches, and regional data-sharing mechanisms. We argue that building agile, equity-centered, and decentralized surveillance systems is not only essential for managing known threats, but also foundational to the early detection and rapid containment of the next public health emergency in resource-limited settings. This review uniquely frames surveillance limitations in resource-limited settings as a global security concern and outlines context-adapted, equity-centered innovations to strengthen epidemic intelligence in preparation for Disease X. Full article

Human immunodeficiency virus (HIV), comprising two distinct types, HIV-1 and HIV-2, remains one of the most significant global health challenges, originating from multiple cross-species transmissions of simian immunodeficiency viruses (SIVs) in the early 20th century. This review traces the evolutionary trajectory of HIV from zoonotic spillover to its establishment as a global pandemic. HIV-1, the principal strain responsible for AIDS, emerged from SIVcpz in Central African chimpanzees, with phylogenetic evidence indicating initial human transmission between the 1920s and 1940s in present day Democratic Republic of Congo. The virus disseminated through colonial trade networks, reaching the Caribbean by the 1960s before establishing endemic transmission in North America and Europe. HIV’s extraordinary genetic diversity—driven by high mutation rates (~10⁻⁵ mutations per base per replication cycle) and frequent recombination events—has generated multiple groups, subtypes, and circulating recombinant forms (CRFs) with distinct epidemiological patterns. HIV-1 Group M, comprising subtypes A through L, accounts for over 95% of global infections, with subtype C predominating in sub-Saharan Africa and Asia, while subtype B dominates in Western Europe and North America. The extensive genetic heterogeneity of HIV significantly impacts diagnostic accuracy, antiretroviral therapy efficacy, and vaccine development, as subtypes exhibit differential biological properties, transmission efficiencies, and drug resistance profiles. Contemporary advances, including next-generation sequencing (NGS) for surveillance, broadly neutralizing antibodies for cross-subtype prevention and therapy, and long-acting antiretroviral formulations to improve adherence, have transformed HIV management and prevention strategies. NGS enables near real-time surveillance of drug resistance mutations and inference of transmission networks where it is available, although access and routine application remain uneven across regions. Broadly neutralizing antibodies demonstrate cross-subtype efficacy, while long-acting formulations have the potential to improve treatment adherence. This review synthesizes recent evidence and offers actionable recommendations to optimize clinical and public health responses—including the routine use of genotypic resistance testing where feasible, targeted use of phylogenetic analysis for outbreak investigation, and the development of region-specific diagnostic and treatment algorithms informed by local subtype prevalence. While the understanding of HIV’s evolutionary dynamics has substantially improved and remains essential, translating this knowledge into universally implemented intervention strategies remains a key challenge for achieving the UNAIDS 95-95-95 targets and the goal of ending AIDS as a public health threat by 2030. Full article

To investigate the role of epidemic predictors in the mpox outbreak in Africa. This was a retrospective analysis of national-level mpox surveillance data from 20 mpox-affected African countries from January through December 2024. Predictors included viral clades, gross domestic product (GDP) per capita, and population density. A negative binomial regression model estimated the incidence rates ratio (IRR) [95% confidence interval] for mpox incidence and mortality. Random forest models assessed the influence of each predictor in the epidemic dynamic. Clade II was associated with lower mpox incidence (IRR = 0.15 [0.02–0.97]) and mortality (IRR = 0.09 [0.01–1.72]) compared to Clade I. GDP per capita was associated with a 95% reduction in cases count per US $1000 (IRR = 0.05 [0.38–0.74]). Population density was not significantly associated with mpox incidence or mortality. Random forest analysis confirmed GDP per capita as the strongest predictor of mpox burden. The 2024 mpox epidemic highlights how countries with low GDP per capita and Clade I face greater outbreak burdens. Strengthening health systems and addressing poverty as a key social determinant of health through a multisectoral approach are essential to ensure equitable outbreak prevention, control, and long-term resilience. Full article

Forests play a vital role in the global carbon cycle; however, the carbon sink capacity of African forests is increasingly threatened by wildfires, rising temperatures, and ecological degradation. This study analyzes the spatiotemporal dynamics of forest carbon fluxes across Africa from 2001 to 2023, based on multi-source remote sensing and climate datasets. The results show that wildfires have significantly disrupted Africa’s carbon balance over the past two decades. From 2001 to 2023, fire activity was most intense in the woodland–savanna transition zones of Central and Southern Africa. In countries such as the Democratic Republic of the Congo, Angola, Mozambique, and Zambia, each recorded burned areas exceeding 500,000 km², along with high recurrence rates (e.g., up to 0.7584 fires per year in South Sudan). These fire-affected regions often exhibited high ecological sensitivity and carbon density, which led to pronounced disturbances in carbon fluxes. Nevertheless, the Democratic Republic of the Congo maintained an average annual net carbon sink of 74.2 MtC, indicating a high potential for ecological recovery. In contrast, Liberia and Eswatini exhibited net carbon emissions in fire-affected areas, suggesting weaker ecosystem resilience. These findings underscore the urgent need to incorporate wildfire disturbances into forest carbon management and climate mitigation strategies. In addition, climate variables such as temperature and soil moisture also influence carbon fluxes, although their effects display substantial spatial heterogeneity. On average, a 1 °C increase in temperature leads to an additional 0.347 (±1.243) Mt CO₂ in emissions, while a 1% increase in soil moisture enhances CO₂ removal by 1.417 (±8.789) Mt. However, compared to wildfires, the impacts of these climate drivers are slower and more spatially variable. Full article

Mpox, caused by the Mpox virus (MPXV), is a re-emerging zoonotic disease in the Poxviridae family. Since 2022, sub-Saharan Africa has experienced recurrent outbreaks, with the Democratic Republic of the Congo (DRC) accounting for 96% of the 567 confirmed cases reported in the African region by the World Health Organization as of June 2024. Despite MPXV’s endemic presence, its genomic diversity and evolutionary dynamics remain poorly characterized. We analyzed 270 MPXV genomes from 13 sub-Saharan African countries (2022–2024), representing the most geographically comprehensive regional dataset from the outbreak period. Phylogenetic analysis identified two geographically distinct clades: Clade I (East/Central Africa) and Clade II (West/Southern Africa). A marked disparity in APOBEC3-associated mutations was observed, with Clade IIb exhibiting significantly higher enrichment than Clade I, suggesting clade-specific host adaptation pressures. These mutations predominantly target genes involved in immune evasion and replication. Preliminary functional predictions indicated that selected missense mutations may impact on protein stability, underscoring the need for further experimental validation. Our findings provide the first pan–sub-Saharan analysis of MPXV clade divergence and reinforce the importance of sustained, regionally informed genomic surveillance to monitor viral evolution and guide outbreak response strategies across Africa. Full article

Tuberculosis (TB) is a global health challenge, particularly in the Central African Republic (CAR), which is classified as a high TB burden country. In the CAR, factors like poverty, limited healthcare access, high HIV prevalence, malnutrition, inadequate sanitation, low measles vaccination coverage, and conflict-driven crowded living conditions elevate TB risk. Improved AI-driven surveillance is hypothesized to address under-reporting and underdiagnosis. Therefore, we created an epidemiological digital representation of TB in Bangui by employing passive data collection, spatial analysis using a 100 × 100 m grid, and mapping TB treatment services. Our approach included estimating undiagnosed TB cases through the integration of TB incidence, notification rates, and diagnostic data. High-resolution predictions are achieved by subdividing the area into smaller units while considering influencing variables within the Bayesian model. By designating moderate and high-risk hotspots, the model highlighted the potential for precise resource allocation in TB control. The strength of our model lies in its adaptability to overcome challenges, although this may have been to the detriment of precision in some areas. Research is envisioned to evaluate the model’s accuracy, and future research should consider exploring the integration of multidrug-resistant TB within the model. Full article

The World Health Organization African region has the greatest infectious disease burden in the world. However, many African countries have limited capacity to rapidly detect, report, and respond to public health events. The Centre for Epidemic Response and Innovation (CERI), KwaZulu-Natal Research Innovation and Sequencing Platform (KRISP) in South Africa, and global Climate Amplified Diseases and Epidemics (CLIMADE) consortium are investing in building the capacity of African scientists in pathogen genomics and bioinformatics. A two-week long (11–21 April 2023) intensive training in wet-laboratory genomic data production, bioinformatics, and phylogenetic analyses of viral and bacterial pathogens was held in Cape Town, South Africa. Training was provided to 36 fellows with diverse backgrounds from 16 countries, 14 of which were low- and middle-income African countries. In this report, we, the fellows, share our collective experiences and describe how the learnt skills have been integrated into the operations of our home institutions to advance genomic surveillance capabilities. We identified the in-person and hands-on learning format of the training, taught by genomics experts and field application specialists, as the most impactful elements of this training event. Adaptation and miniaturisation of protocols to detect other pathogens is a great enhancement over the traditional method of using a single protocol for a pathogen. We note the duration of the training as the largest limiting factor, particularly for the computationally intensive bioinformatics sessions. We recommend this programme continue to build pathogen genomics capacity in Africa. Full article

This study projects the performance of maternal and child mortalities in relation to the SDGs target (70 maternal deaths and 25 child deaths) by year 2030, based on three simulation scenarios of public health expenditures (PHEs). In essence, this study investigates the predictability of PHE in explaining maternal and child mortalities in a bid to confirm the possibility of meeting the SDGs target. The SSA is known to be facing critical health challenges; this study contributes to the problem underlying the health sector by forecasting PHEs in relation to goal 3 because the knowledge of correlation and threshold relationship between PHE and health outcomes, as seen in previous studies, may not be adequate to prepare the SSA countries towards achieving the SDGs target. This study uses Feasible Quasi-Generalised Least Squares as a baseline forecasting approach for 25 selected SSA countries. An increase in the PHE by 30 percent from the current level shows that only Botswana, Namibia, and South Africa will achieve the SDGs target of 70 maternal deaths, while Burundi, Cameroon, Central African Republic, Cote d’Ivoire, Eswatini, Lesotho, Mauritania, Niger, Nigeria, Tanzania, and Togo may have to bear more than 200 maternal deaths by 2030. In contrast, about 60 percent of the countries will achieve the SDGs target for child mortality. PHEs must meet the 30% increase forecasted for a reduction in mortality, being the benchmark that will enable the SSA region to achieve the SDGs target by year 2030. Full article

Background: Since 1974, Essential Programme on Immunisation managers from ten Central African countries meet yearly with partners to review progress made and share experiences and lessons learned from the implementation of immunization programmes. The 2024 meeting occurred in Kinshasa, Democratic Republic of Congo, in September 2024. This conference report summarizes the key takeaways from discussions on using immunization data for decision-making, the implementation of the Big Catch-Up (BCU) initiative to reduce the burden of zero-dose children, and progress and challenges in introducing selected new vaccines. Conference Takeaways: Inaccurate administrative data on routine immunization observed in most countries, compared to WHO/UNICEF Estimates of National Immunization Coverage and national survey estimates, affect timely decisions to improve the Expanded Programme on Immunization (EPI) performance. Five countries in Central Africa are among the priority countries of the BCU initiative but, as of the end of August 2024, are yet to formally start its implementation. Cameroon and Central African Republic introduced the malaria vaccine in January 2024 and August 2024, respectively, while the Democratic Republic of Congo, Chad, and Burundi have planned to do so by 2025. Conclusions and Recommendations: Meeting participants put forward several recommendations for countries and immunization partners, including but not limited to (i) investing more in routine immunization data quality assurance to better use data to inform decisions, (ii) accelerating the implementation of the BCU initiative to close the immunity gap resulting from routine immunization disruptions due to the COVID-19 pandemic, (iii) updating malaria vaccine introduction plans to invest more in demand generation and community engagement, and (iv) learning from Cameroon’s experience in tackling hesitancy to human papilloma virus vaccine. It is critical to set up an appropriate mechanism for monitoring the implementation of these recommendations. Full article

Tropical evergreen forests represent the richest biodiversity in terrestrial ecosystems, and the fine spatial-temporal resolution mapping of these forests is essential for the study and conservation of this vital natural resource. The current methods for mapping tropical evergreen forests frequently exhibit coarse spatial resolution and lengthy production cycles. This can be attributed to the inherent challenges associated with monitoring diverse surface changes and the persistence of cloudy, rainy conditions in the tropics. We propose a novel approach to automatically map annual 10 m tropical evergreen forest covers from 2017 to 2023 with the Sentinel-2 Dynamic World dataset in the biodiversity-rich and conservation-sensitive Central African Republic (CAR). The Copernicus Global Land Cover Layers (CGLC) and Global Forest Change (GFC) products were used first to track stable evergreen forest samples. Then, initial evergreen forest cover maps were generated by determining the threshold of evergreen forest cover for each of the yearly median forest cover probability maps. From 2017 to 2023, the annual modified 10 m tropical evergreen forest cover maps were finally produced from the initial evergreen forest cover maps and NEFI (Non-Evergreen Forest Index) images with the estimated thresholds. The results produced by the proposed method achieved an overall accuracy of >94.10% and a Cohen’s Kappa of >87.63% across all years (F1-Score > 94.05%), which represents a significant improvement over the performance of previous methods, including the CGLC evergreen forest cover maps and yearly median forest cover probability maps based on Sentinel-2 Dynamic World. Our findings demonstrate that the proposed method provides detailed spatial characteristics of evergreen forests and time-series change in the Central African Republic, with substantial consistency across all years. Full article

The feasibility of using brick aggregates for the preparation of aluminosilicate “glass-ceramic” forms as a novel cementitious composite capable of immobilizing radioactive elements was examined. Raw brick was initially activated with sodium hydroxide. X-ray diffraction analysis (XRD) confirmed zeolites (Na-A and Na-P), illite, and sand (quartz) as major phases. Thermal analysis showed several successive events: dehydration/dehydroxylation of illite, followed by degradation of illite and zeolites. Upon heating to 1000 °C, scanning electron microscopy and XRD provided evidence of the presence of novel crystalline aluminosilicate forms (analcime and leucite in the form of solid solutions). Then, upon heating to 1150 °C, the thermal process led to the additional formation of mullite and an amorphous silica-rich phase. The latter resulted from silica melting taking place, owing to the involvement of low-melting-point components on sand grains. Alkali-brick particles were then doped with Cs⁺, Rb⁺, Ca²⁺, and Sr²⁺ ions (individually) and subsequently heated at different temperatures. The corrosion resistance of the heated materials was examined in a hydrochloride acid solution. The aim was to highlight (i) the enhanced cationic-immobilization capacity of crystalline aluminosilicate phases embedded inside amorphous silica, and (ii) the role of sand in the creation of brick-based glass ceramics. Full article

Background/Objectives: Yellow fever (YF) outbreaks continue to affect populations that are not reached by routine immunization services, such as workers at a high risk of occupational exposure to YF. In the Central African Republic (CAR), YF cases were detected in districts characterized by the presence of workers in forest areas. We developed an innovative approach based on a local partnership with private companies of the extractive industry to administer YF vaccine to workers in remote areas during the response to an outbreak. Methods: The planning stage of the campaign included the mapping of forestry and mining companies through the involvement of national and/or local representatives of companies from both the formal and informal sectors. Information sessions and mobilization targeted the heads of operating companies. Advanced and mobile strategies were used to target workers on their work site. Companies provided logistical support including transportation and communication and set up temporary vaccination posts. Results: Using this local partnership, it was possible to vaccinate over 70,000 workers (5.8% of the entire vaccinated population) in hard-to-reach areas, protecting them from YF. This represented around 47% of the estimated number of workers and dependents. The partnership with the private sector also contributed to increasing knowledge on the risk of YF and means of protection among a high-risk community. Conclusions: Private companies represent potentially useful actors that can contribute to the protection of high-risk workers and to the prevention and control YF outbreaks. The experience in the CAR has demonstrated that it is possible to obtain support from private companies, including informal ones, for a vaccination campaign. Full article

Background: Gastric diseases caused, in particular, by Campylobacter, non-typhoidal Salmonella, and Shigella resulting from food and/or water problems, are a disproportionately distributed burden in developing countries in Central Africa. The aim of this work was to compile a list of studies establishing the prevalence of the involvement of these bacterial genera in diarrheal syndromes in Central Africa from 1998 to 2022. Methods: The Preferred Reporting Articles for Systemic Reviews and Meta-Analyses, six (6) database (Pubmed, Google Scholar, Semantic Scholar, Freefullpdf, and Scinapse) were perused for research on the role of Campylobacter, Salmonella and Shigella diarrheal infections in humans and animals, in 9 country of Central Africa over from 1998 to 2022. Results: Seventeen articles were selected, including 16 on humans and one on animals. These data were recorded in 6 of the 9 countries of Central Africa, including Gabon (5), Angola (3), Cameroon (3), the Democratic Republic of Congo (3), Chad (2), and the Central African Republic (1). Mono-infections with Salmonella spp. were the most predominant (55.56%, n = 5/9), followed by an equal proportion of Campylobacter spp. and Shigella spp. with 44.44% (4/9), respectively and, co-infections with Campylobacter/Salmonella spp. and Salmonella/Shigella spp. with a prevalence of 11.11% (1/9) respectively. The most used diagnostic tool was conventional culture (82.35%) against 17.65% for PCR or real-time PCR. Conclusion: Despite the paucity of recorded data on the prevalence of diarrheal infections due to Campylobacter in this sub-region, it is crucial that scientific studies focus on the diagnosis and monitoring of this zoonotic bacterium. Also, improved diagnosis will necessarily involve the integration of molecular tools in the diagnosis of these diarrheic syndromes in both humans and animals. Full article

Snakes responsible for bites are rarely identified, resulting in a loss of information about snakebites from venomous species whose venom effects are poorly understood. A prospective clinical study including patients bitten by a snake was conducted in Cameroon between 2019 and 2021 to evaluate the efficacy and tolerability of a marketed polyvalent antivenom. Clinical presentation during the first 3 days of hospitalization was recorded following a standardized protocol. This ancillary study aimed to assess the frequency of bites by the different species encountered in Cameroon and to describe the symptoms of bites by formally identified species. Of the 447 patients included in the study, 159 (35.6%) brought the snake that caused the bite that was identified by a specialist. Out of these, 8 specimens could not be identified due to poor condition, 19 were non-venomous species, and 95 belonged to Echis romani—formerly E. ocellatus—species. The remaining 37 specimens included 2 Atheris squamigera, 12 Atractaspis spp., 2 Bitis arietans, 11 Causus maculatus, 1 Dendroaspis jamesoni, 1 Naja haje, 1 N. katiensis, 5 N. melanoleuca complex, and 2 N. nigricollis. Symptoms, severity of envenomation, and post-treatment course are described. Symptoms and severity of bites are consistent with cases described in the literature, but some specific features are highlighted. Full article