Search Results (39)

Drought in Angola is a recurrent and cyclical natural phenomenon that poses significant environmental, economic, and social challenges, affecting water resources, agriculture, ecosystems, livestock, and vulnerable communities. This study investigates the temporal evolution and spatial behavior of drought in the provinces of Cunene, Huila, and Namibe over the period 1980–2024. Drought conditions were assessed using the Standardized Precipitation Index (SPI) and the Standard Precipitation–Evapotranspiration Index (SPEI) at multiple time scales. Trends were evaluated using the Modified Mann–Kendall test and Sen’s slope estimator, while drought intensity was analyzed using run theory. The results reveal a clear intensification of drought conditions in the last decade, characterized by an increase in frequency and intensity, particularly after 2010. Extreme drought events were identified in the early 1980s, the mid-1990s, and more recently in 2019 and 2021. Despite some regional variability, the three provinces exhibit consistent temporal patterns, with drought events generally occurring simultaneously over the study period. These findings highlight the increasing pressure on water and environmental systems and underscore the need for improved drought monitoring and forecasting approaches to support more effective adaptation and decision-making. Full article

This study investigates the seasonal and latitudinal variability of the key physical properties of seawater along the Angolan coast, focusing on temperature, salinity, density, and dissolved oxygen. Vertical profile data from the World Ocean Database (2005–2020) were analyzed using Ocean Data View to examine stratification patterns and their relationship with regional circulation features, including the Angola–Benguela Front and coastal upwelling. The results reveal a pronounced south–north gradient, with colder, saltier, and denser surface waters in the southern sector during the cold season, indicative of intensified upwelling influence. The vertical structure is characterized by a surface mixed layer extending to approximately 20–30 m underlain by a sharp thermocline, halocline, and pycnocline between 25 m and 50 m. Dissolved oxygen profiles show the presence of an oxygen minimum layer below the thermocline, particularly pronounced in the central and southern regions, reflecting limited ventilation of subsurface waters. These findings highlight the combined role of stratification, regional circulation, and upwelling dynamics in shaping the physical structure of the Angolan coastal ocean and provide a baseline for future studies in a region that remains poorly documented. Full article

Rabies is an acute, progressive, viral encephalitis. Warm-blooded vertebrates are susceptible. Major reservoirs reside in the Chiroptera and Carnivora. Among the latter, representatives include dogs, ferret badgers, foxes, jackals, mongooses, raccoons, and skunks. Within the Carnivora, pinnipeds represent a diverse group of >30 extant species. These marine mammals range from the Arctic to Antarctica, but there is no review about rabies in this group. Apparently, only a single 1980 case of rabies occurred from Svalbard in a ringed seal (Phoca hispida). However, in 2024, incidental cases appeared within South African Cape fur seals (Arctocephalus pusillus). Retrospective testing of archival material identified suspect cases dating back to 2022. Currently, more than 80 cases have been documented in seals. Moreover, a new 2025 focus appeared in Namibia and cases in Angola are predictable. Viral characterization supports spillover infection via rabid black-backed jackals (Lupulella mesomelas). A host shift appears likely, with ongoing seal intraspecific transmission. Given the unique nature of this epizootic, implications for the southern hemisphere abound. Unfortunately, comprehensive data are lacking on pinniped specimens examined outside of southern Africa. For example, although Antarctica is considered ‘rabies-free’, minimal international standards for support are unmet. No routine laboratory-based surveillance occurs. This enzootic rabies focus among seals in southern Africa presents unique challenges for the region and a rare opportunity for considering broader surveillance. Besides targeted parenteral vaccination of fur seals, local engagement involves vagrant species, including elephant (Mirounga leonina) and leopard seals (Hydrurga leptonyx). The void of regional pinniped surveillance, especially encompassing the Southern Ocean would require considerable proactive local resolution and much wider collaboration regarding future concerns to both public health and conservation biology. Full article

Background/Objectives: Antimicrobial resistance (AMR) among Enterobacterales poses a major threat to public health in Southern Africa and has led to limited treatment options and increased mortality. Despite Africa bearing the brunt, there is limited data on the epidemiology and molecular epidemiology of the genetic determinants of β-lactam and/or carbapenem resistance. This narrative literature review summarizes the epidemiology and molecular characteristics of extended-spectrum β-lactamase-producing Enterobacterales (ESBL-PE), carbapenem-resistant Enterobacterales (CRE), and carbapenemase-producing Enterobacterales (CPE) in Southern Africa, while identifying data gaps and surveillance challenges. Methods: A comprehensive literature review was conducted using peer-reviewed articles from ten Southern African countries, including South Africa, Lesotho, Eswatini, Botswana, Namibia, Angola, Zambia, Zimbabwe, Mozambique, and Malawi, reporting the epidemiology and/or molecular characterization of ESBL-PE, CRE, and CPE. Results: ESBL-PE, CRE, and CPE pose an increasing healthcare threat in Southern Africa, with prevalence varying widely by source. Klebsiella pneumoniae and E. coli are the predominant ESBL-PE, CRE, and CPE species. The most frequent resistance genes are bla_CTX-M among ESBLs and bla_NDM and bla_OXA among carbapenemases, reflecting global patterns. However, molecular characterization across the region remains limited, with countries such as Botswana, Lesotho, Eswatini, Zambia, and Zimbabwe lacking sufficient data on the prevalence and diversity of these resistance determinants. Conclusions: Despite the paucity of genomic and epidemiological data, Southern Africa faces an urgent AMR challenge. Strengthening laboratory infrastructure, genomic surveillance, and regional coordination is crucial to mitigate AMR and guide antibiotic stewardship policies. Full article

Background/Objectives: In Brazil, quilombos—African-descendant resistance communities—emerged during slavery and persisted beyond its abolition. The state of Paraná, in Southern Brazil, is home to 86 quilombos, yet their genetic diversity remains entirely unexplored, and little is known about their subcontinental African origins. Methods: To explore the demographic history of these communities and the reach of the Transatlantic Slave Trade in Southern Brazil, we analyzed Y and mitochondrial DNA haplotypes in samples from two quilombo communities from Paraná, Feixo (n = 117) and Restinga (n = 47). Results: Our findings reveal a significant African maternal ancestry in both communities, with Feixo exhibiting 35% and Restinga showing a striking 78.72% of maternal haplogroups of African origin. Feixo’s mtDNA haplotypes display affinities with Bantu-speaking populations from Central-Western and Southeastern Africa (such as Angola, Congo, and Mozambique), whereas those found in Restinga are more closely aligned with lineages frequent in Western Africa. Y-chromosome data reveal 39.4% and 25% African paternal ancestry in Feixo and Restinga, respectively, with most African chromosomes assigned to haplogroup E1b1b1-M35, which has a broad frequency across eastern Africa. Conclusions: These results offer novel insights into the history of the African diaspora in a previously unstudied Brazilian region, suggesting African sources—including underdocumented Eastern/Southern lineages—and contributing useful new clues to their broader within-Africa affinities. Full article

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

Phosphorus (P) is an essential element for plant growth, yet it is only available to plants in the form of orthophosphate. In most soils, P occurs predominantly in insoluble forms, such as calcium phosphates in alkaline soils and aluminum/iron phosphates in acidic soils, limiting plant uptake. Fertilization is commonly used to overcome this limitation; however, large fractions of applied P rapidly become unavailable. Phosphorus-solubilizing bacteria (PSB) are a sustainable alternative to enhance P availability. This study evaluated the P-solubilization capacity of bacterial strains belonging to different genera isolated from different host plants, soil types, and climates (mainland Portugal, Cape Verde, and Angola). Following initial screening, the most efficient strains were tested under greenhouse conditions in soils with pH 7 and 8. Strains exhibited diverse solubilization capacities, with highly efficient PSB (phosphate solubilization index ≥ 2) accounting for 5% of the total isolates, predominantly originating from the Namib Desert (Angola) and Southern Portugal, and mainly belonging to the genera Pseudomonas, Flavobacterium, Enterobacter, Chryseobacterium and Pantoea. At pH 7, most PSB promoted maize growth, with strain C11 increasing plant P content around 2-fold compared to the control. At pH 8, fewer strains were effective, but strains F and C11 enhanced shoot weight and M shoot length by 28%, 27%, and 10%, respectively. These findings highlight the potential of selected PSB strains as next-generation bioinoculants for sustainable agriculture. However, strain selection must consider geography, crop type, and management practices to ensure consistent efficacy, thereby supporting the broader application of PSB as a precision tool for improving food security. Full article

Climate change poses a significant challenge to agriculture in southern Angola, particularly for smallholder farming systems that are highly exposed and vulnerable, lacking the resources and capacity to respond effectively. This study analyses climate trends from 1950 to 2024 in Huíla, Namibe, and Cunene, focusing on eight variables: Tmax, Tmin, Tmean, PRCPTOT, R95p, R95pTOT, CDD, and CWD. Due to inconsistencies in local meteorological station data, ERA5-Land reanalysis was used. Trends such as rising Tmin in Namibe (+0.32 °C/decade), Tmean in Huíla (+0.16 °C/decade), and increased precipitation in Huíla (+29.3 mm/decade), along with fewer dry days in Namibe (–2.7 days/decade), were observed. Crop–climate relationships (2000–2023) were explored using a categorical contingency analysis. Maize showed its highest yield frequency (46%) during hot years; cassava and beans were more stable under cooler, drier conditions; millet yielded above average (31%) in dry years, confirming drought resilience; potatoes performed poorly in wet years (17% above-average yields). The contingency method provided insights where linear models were insufficient, helping to understand climate–yield interactions in data-limited environments. This study offers the first long-term climate–agriculture assessment for southern Angola, providing critical evidence for climate-informed agricultural strategies in regions with scarce and unreliable observational records. The findings emphasise the urgent need for adaptation policies focused on crop-specific climate vulnerabilities. They also demonstrate the value of combining reanalysis data and categorical analysis to overcome data gaps and guide sustainable agricultural planning. 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

Agricultural production in southern Angola faces challenges due to unsustainable practices, including inefficient use of water, fertilizers, and machinery, resulting in low yields and environmental degradation. Therefore, clear and measurable indicators are needed to guide farmers toward more sustainable practices. The scientific literature insufficiently addresses this issue, leaving a significant gap in the evaluation of key performance indicators (KPIs) that can guide good agricultural practices (GAPs) adapted to the context of southern Angola, with the goal of promoting a more resilient and sustainable agricultural sector. So, the objective of this study is to identify and assess KPIs capable of supporting the selection of GAPs suitable for maize, potato, and tomato cultivation in the context of southern Angolan agriculture. A systematic literature review (SLR) was conducted, screening 2720 articles and selecting 14 studies that met defined inclusion criteria. Five KPIs were identified as the most relevant: gross margin, net profit, water use efficiency, nitrogen use efficiency, and machine energy. These indicators were analyzed and standardized to evaluate their contribution to sustainability across different GAPs. Results show that organic fertilizers are the most sustainable option for maize, drip irrigation for potatoes, and crop rotation for tomatoes in southern Angola because of their efficiency in low-resource environments. A clear, simple, and effective representation of the KPIs was developed to be useful in communicating to farmers and policy makers on the selection of the best GAPs in the cultivation of different crops. The study proposes a validated KPI-based methodology for assessing sustainable agricultural practices in developing regions such as southern Angola, aiming to lead to greater self-sufficiency and economic stability in this sector. Full article

Rainfall variability in the sensitive Kalahari semi-desert in Southern Africa, a region of strong climatic gradients, has not been much studied and is poorly understood. Here, anomalies in rainfall totals and moderate and heavy rain day frequencies are examined for both the summer half of the year and three bi-monthly seasons using CHIRPS rainfall data and ERA5 reanalysis. Peak rainfall occurs in January–February, with anomalously wet summers marked by a significant increase in the number of rainy days rather than rainfall intensity. Wet summers are linked to La Niña events, cyclonic anomalies over Angola, and a weakened Botswana High, which enhances low-level moisture transport and convergence over the region as well as mid-level uplift. Roughly the reverse patterns are found during anomalously dry summers. On sub-seasonal scales, ENSO and the Botswana High (the Southern Annular Mode) are negatively (positively) significantly correlated with early summer rainfall, while in mid-summer, and for the entire November–April season, only ENSO and the Botswana High are correlated with rainfall amounts. In the late summer, weak negative correlations remain with the Botswana High, but they do not achieve 95% significance. Full article

Small pelagic fishes such as Sardinella aurita (Valenciennes, 1847) and Sardinella maderensis (R. T. Lowe, 1838) are key intermediate-level components of the marine food web of the southwestern African coast. Their biomass off Angola has shown significant interannual variability, and information about their reproduction is insufficient in the region for adequate stock management. Thus, we aimed to unveil the reproduction period and reproductive traits of these two Sardinella species and establish a link with the prevailing ocean temperature conditions. Adult fish samples were obtained monthly from artisanal and semi-industrial fleets, and the ichthyoplankton samples were collected with a Hydro-Bios Multinet off southwest Angola by Instituto Nacional de Investigação Pesqueira (Angola). The macroscopic inspection of gonads showed that females of both species were more abundant than males. The gonadosomatic index and maturity stages indicate that S. aurita spawns during the Austral summer (December through March), while S. maderensis has a longer spawning period, from October to April. The spawning peak occurs in February for S. aurita and S. maderensis. The mean monthly condition factor of both species was high before and after spawning seasons. The females of S. aurita reach sexual maturity at a smaller size than males, and 50% of the population reaches sexual maturity at a total length of 31.3 cm. The males of S. maderensis reach sexual maturity at a smaller size than females, and 50% of the population reaches sexual maturity at a total length of 28.4 cm. We also found that both species use the southern coast of Angola as a spawning area during the Austral summer and avoid the area during periods of intense upwelling. Currently, these species are managed as a single unit, and the minimum capture size is set at 22 cm, well below the size at sexual maturity registered in the study area. Therefore, we strongly recommend increasing the minimum capture size to guarantee long-term stock viability. Full article

Semi-annual climate oscillations in the Western Hemisphere (20 S–35 N, 150 W–20 E) were studied via empirical orthogonal function (EOF) eigenvector loading patterns and principal component time scores from 1980 to 2023. The spatial loading maximum for 850 hPa zonal wind extended from the north Atlantic to the east Pacific; channeling was evident over the southwestern Caribbean. The eigenvector loading maximum for precipitation reflected an equatorial trough, while the semi-annual SST formed a dipole with loading maxima in upwelling zones off Angola (10 E) and Peru (80 W). Weakened Caribbean trade winds and strengthened tropical convection correlated with a warm Atlantic/cool Pacific pattern (R = 0.46). Wavelet spectral analysis of principal component time scores found a persistent 6-month rhythm disrupted only by major El Nino Southern Oscillation events and anomalous mid-latitude conditions associated with negative-phase Arctic Oscillation. Historical climatologies revealed that 6-month cycles of wind, precipitation, and sea temperature were tightly coupled in the Western Hemisphere by heat surplus in the equatorial ocean diffused by meridional overturning Hadley cells. External forcing emerged in early 2010 when warm anomalies over Canada diverted the subtropical jet, suppressing subtropical trade winds and evaporative cooling and intensifying the equatorial trough across the Western Hemisphere. Climatic trends of increased jet-stream instability suggest that the semi-annual amplitude may grow over time. Full article

In 2023, the HIV-1 pandemic claimed around 630,000 lives worldwide due to AIDS-related complications. Its burden is significantly heavier in Sub-Saharan Africa, where an increased HIV-1 genetic diversity is common, which increases the risk of resistance to antiretroviral (ARV) drugs. This study aims to update the molecular epidemiology of HIV-1 in Angola, focusing specifically on the gag gene, which is often overlooked, and to assess the potential viability of lenacapavir (LEN)-based ARV therapy in the region. A total of 243 blood samples were collected from ARV-naïve, HIV-infected patients at the General Hospital of Benguela, city of Benguela, Angola. The capsid-encoding region of HIV-1 proviral DNA was amplified by PCR and sequenced. Phylogenetic analysis was performed using the maximum likelihood method, and genome recombinant forms were characterised through bootscanning analysis. Primary resistance mutations to LEN were identified using Stanford University’s HIVdb algorithm. Among the 80 successfully sequenced samples, 13 different genetic forms/subtypes were identified, with unique recombinant forms (URFs) (37.5%, 30/80) and subtype C (31.25%, 25/80) being the most prevalent. Regarding resistance mutations, none were detected, apart from four polymorphic mutations. These findings reinforce Angola’s position as a transitional HIV-1 hotspot between the genetically highly diverse Central Africa and the subtype C-dominated Southern Africa, while also supporting the potential effectiveness of LEN-based regimens for treatment and prevention of HIV-1 infections in the future. Full article

The Okavango River is a transboundary waterway that flows through Angola, Namibia, and Botswana, forming a significant alluvial fan in northwestern Botswana. This fan creates a Delta that plays a vital role in the country’s GDP through tourism. While research has primarily focused on the Delta, the river’s catchment area in the Angolan highlands—its main water source and critical for downstream flow—has been largely overlooked. The basin is under pressure from development, water abstraction, and population growth in the surrounding areas, which negatively affect the environment. These challenges are intensified by climate change, leading to increased water scarcity that necessitates improved management strategies. Currently, there is a lack of published research on the basin’s hydrology, leaving many hydrological parameters related to streamflow in the catchments inadequately understood. Most existing studies have employed single-site calibration methods, which fail to capture the diverse characteristics of the basin’s catchments. To address this, a SWAT model has been developed to simulate the hydrologic behaviour of the basin using sequential multisite calibration with data from five gauging stations, including the main river systems: Cubango and Cuito. The SUFI2 program was used for sensitivity analysis, calibration, and validation. The initial sensitivity analysis identified several key parameters: the Soil Evaporation Compensation Factor (ESCO), the SCS curve number under moisture condition II (CN2), Saturated Hydraulic Conductivity (SOL_K), and Moist Bulk Density (SOL_BD) as the most influential. The calibration and validation results were generally satisfactory, with a coefficient of determination ranging from 0.47 to 0.72. Analysis of the water balance and parameter sensitivities revealed the varied hydrologic responses of different sub-watersheds with distinct soil profiles. Average annual precipitation varies from 1116 mm upstream to 369 mm downstream, with an evapotranspiration-to-precipitation ratio ranging from 0.47 to 0.95 and a water yield ratio between 0.51 and 0.03, thereby revealing their spatial gradients, notably increasing evapotranspiration and decreasing water yield downstream. The SWAT model’s water balance components provided promising results, with soil moisture data aligned with the TerraClimate dataset, achieving a coefficient of determination of 0.63. Additionally, the model captured the influence of the El Niño–Southern Oscillation (ENSO) on local hydrology. However, limitations were noted in simulating peak and low flows due to sparse gauge coverage, data gaps (e.g., groundwater abstraction, point sources), and the use of coarse-resolution climate inputs. Full article