Southeastern Africa Research Articles

Morphology and ecological significance of Holocene palynomorphs from the Indian Ocean Coastal Belt Biome of South Africa

Palynomorphs are indicators of past vegetation change. Since it is accepted that vegetation reflects the local climate, based on modern analogues, palynological analyses are a good proxy for climates of the past. In view of a demand for information on palynomorph types to support palaeoclimatic studies, we present an atlas of palynomorph taxa from the Indian Ocean Coastal Belt of eastern South Africa and Mozambique. Photomicrographs of the fossils are provided as well as brief descriptions and ecological information obtained from the literature. The palynomorphs in this atlas represent a vast variety of pollen, spores (algae, pteridophytes and fungi) and other palynomorphs such as types that were derived from the marine environment and incorporated into the lagoonal deposits. The holistic analysis of all microfossils found here is intended to assist palaeoecological interpretations of wetland dynamics, fire regimes, climate fluctuations and anthropogenic disturbances in the Indian Ocean Coastal Belt.

Along the shoreline of Southeastern Africa

Les ciutats costaneres i els punts de partida de les illes del sud-est d’Àfrica des dels quals es transportaven els africans esclavitzats als mercats regionals i de llarga distància es torben al centre d’aquest article de recerca. Les rutes comercials costaneres, les societats litorals i insulars i les múltiples xarxes de treballadors que es dediquen al comerç de béns i persones esdiscuteixen aquí per interrogar el desenvolupament, les fluctuacions i la importància de les operacions d’esclavització vinculades als treballadors esclavitzats ‘‘Moçambics’’ que van marxar el continent africà des de la costa sud-est. Es tracten dues qüestions principals: Com es va connectar l’organització del trànsit a la costa del sud-est d’Àfrica amb altres zones d’esclavitud costaneres de la regió de l’Àfrica oriental i amb altres mercats intra-oceànics situats tant a l’oceà Índic com a l’Atlàntic? I aquest patró va canviar amb el temps?

An annotated checklist of the mammals of the Chimanimani National Park, Mozambique

The Chimanimani Mountains of Mozambique and Zimbabwe harbour diverse and unique flora and fauna. Because of these unique floral characteristics, this region has received considerable attention by botanists. In contrast, the vertebrates occurring here have received little attention. The aim of this paper was to synthesise data collected on multiple recent surveys into the first annotated checklist of the mammals of the Mozambican side of the Chimanimani Mountains. We identified medium-sized and large mammals by exterior appearance, mostly as captured on camera traps. We combined morphological and molecular methods to identify small mammals, and we report on echolocation calls of some of the poorly known bat species. In total, we recorded 69 species, including 23 species of bats (Chiroptera), 15 species of rodents (Rodentia), 11 species of carnivores (Carnivora), nine species of ungulates (Cetartiodactyla), and the rest comprising Primates, Eulipotyphla, Lagomorpha, Proboscidea, and Pholidota. Of these, five species are listed as threatened, demonstrating the importance of the Chimanimani Mountains for mammalian biodiversity conservation in South Eastern Africa.

Optimisation, Synthesis, and Characterisation of ZnO Nanoparticles Using Leonotis ocymifolia (L. ocymifolia) Leaf Extracts for Antibacterial and Photodegradation Applications.

This work presents a green synthesis route, which utilises extracts from an indigenous plant in South Africa, eastern and southern Africa that is understudied and underutilised, for preparing zinc oxide nanoparticles (ZnO NPs). This study involved optimisation of the green synthesis method using Leonotis ocymifolia (L.O.) extracts and performing comparative studies on the effects of using different zinc (Zn) salt precursors; zinc sulphate heptahydrate (Z001) and zinc acetate dihydrate (Z002) to synthesise the ZnO NPs. The comparative studies also compared the L.O-mediated ZnO NPs and chemical-mediated ZnO NPs (Z003). The as-prepared ZnO NPs were tested for their effectiveness in the photodegradation of methylene blue (MB) dye. Furthermore, antibacterial studies were conducted using the agar well diffusion method on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) bacteria. The structural, morphological, and optical characteristics of the synthesised ZnO NPs were analysed using XRD, FTIR, SEM, EDS, DRS, and BET techniques. The XRD results indicated that the L.O-mediated ZnO NPs had smaller crystallite sizes (18.24-19.32 nm) than their chemically synthesised counterparts (21.50 nm). FTIR confirmed the presence of biomolecules on the surface of the L.O-mediated NPs, and DRS analysis revealed bandgap energies between 3.07 and 3.18 eV. The EDS results confirmed the chemical composition of the synthesised ZnO NPs, which were made up of Zn and O atoms. Photocatalytic studies demonstrated that the L.O-mediated ZnO NPs (Z001) exhibited a superior degradation efficiency of the MB dye (89.81%) compared to chemically synthesised ZnO NPs (56.13%) under ultraviolet (UV) light for 240 min. Antibacterial tests showed that L.O-mediated ZnO NPs were more effective against S. aureus than E. coli. The enhanced photocatalytic and antibacterial properties of L.O-mediated ZnO NPs highlight their potential for environmental remediation and antimicrobial applications, thus supporting sustainable development goals.

Phylogeographic structuring in a widespread southern African grass snake (Psammophiinae: Psammophylax rhombeatus)

ABSTRACT The structural and environmental heterogeneity within southern Africa has given rise to many morphological forms of Psammophylax rhombeatus distributed throughout the country, with previous studies neglecting the associated molecular significance of these forms. The species’ widespread, generalist ecology coupled with the substantial phylogenetic structuring previously acknowledged within the species, makes P. rhombeatus the ideal candidate for phylogeographic analyses. Using 103 samples, representing the full distribution of the species, phylogenetic analyses retrieved four well-supported clades: south-eastern South Africa, south-western South Africa, north-eastern South Africa and western South Africa. Although not variable enough to warrant taxonomic re-evaluation, the clades are phylogenetically distinguishable, with relatively high intraspecific genetic divergence values separating them, irrespective of the small geographic distances separating populations. This is likely a product of the taxon’s habitat-generalist lifestyle, enabling them to bypass vicariant barriers that might otherwise cause speciation in less versatile species. The clades are also geographically distinct, with little overlap, indicating previous vicariance, a finding that is supported by the split of P. rhombeatus from P. ocellatus in the mid-Pliocene, followed by the diversification of P. rhombeatus into four clades throughout the Pleistocene. The genetic structuring observed in P. rhombeatus may be a product of population expansion following ancient refugial isolation (potentially Last Glacial Maximum). The morphological groupings highlighted in previous studies are loosely attributable to the molecular clades identified in the phylogenetic reconstruction, highlighting the complex interplay of genetic and morphological characteristics in the process of speciation, and their representation in systematic accounts.

Ablation of Supraventricular Arrhythmias With as Low as Reasonably Achievable X-Ray exposure (AALARA): Results of Prospective, Observational, Multicenter, Multinational, Open-Label Registry Study on Real World Data Using Routine Ensite 3D Mapping During SVT Ablation.

The reduction of fluoroscopic exposure during catheter ablation of supraventricular arrhythmias is widely adopted by experienced electrophysiology physicians with a relatively short learning curve and is becoming the standard of care in many parts of the world. While observational studies in the United States and some parts of Western Europe have evaluated the minimal fluoroscopic approach, there are scarce real-world data for this technique and the generalizability of outcomes in other economic regions. The AALARA study is a prospective, observational, multicenter, and multinational open-label study. Patients were recruited from 13 countries across Central Eastern Europe, North and South Africa, the Middle East, and the CIS (Commonwealth of Independent States), with different levels of operator expertise using minimal fluoroscopic exposure techniques. Data on radiation exposure, procedural success, complications, recurrence, and quality of life changes were collected and analyzed. A total of 680 patients were enrolled and followed for 6 months. The majority were ablation naïve with the commonest arrhythmia ablated being typical AVNRT (58%) followed by Atrial Flutter (23%). Zero fluoroscopy exposure was observed in almost 90% of the cases. Fluoroscopy was most commonly used during the ablation phase of the procedure. We observed a high acute success rate (99%), a low complication rate (0.4%), and a 6-month recurrence rate of 3.8%. There was a significant improvement in the patient's symptoms and quality of life as measured by patient global assessment. The routine use of a 3D mapping system during right-sided ablation was associated with low radiation exposure and associated with high acute success rate, low complications, and recurrence rate along with significant improvement in quality of life. The data confirm the reproducibility of this approach in real-world settings across different healthcare systems, and operator experience supporting this approach to minimize radiation exposure without compromising efficacy and safety. NCT04716270.

Detrital zircon in Pleistocene aeolianite of the Isipingo Formation at Cape Vidal, KwaZulu-Natal, South Africa, gives age and Hf isotope signatures without provenance significance

Abstract Pleistocene (50 to 70 ka) aeolianite of the Isipingo Formation (Maputaland Group) at Cape Vidal, northern KwaZulu-Natal province, South Africa, contains a combination of three detrital zircon age fractions (A: 940 to 1150 Ma, B: 470 to 720 Ma, C: 230 to 280 Ma) that are also known from Holocene sediments in eastern South Africa, Mesozoic – Cenozoic sandstones in southern Mozambique and from the Carboniferous to Jurassic Karoo Supergroup. Archaean and Palaeoproterozoic bedrock of the Kaapvaal Craton, which is exposed in the drainage basins of rivers that have provided detritus to coastal sedimentary basins, is represented by one single Archaean zircon. Combined laser Raman micro-spectroscopy and estimates of accumulated alpha radiation dose from U and Th concentrations indicate that the virtual absence of zircon older than late Mesoproterozoic cannot be attributed to selective removal of radiation-damaged zircon grains by abrasion during erosion and transport. The Isipingo Formation sandstone at Cape Vidal is a product of sedimentary recycling, potentially involving river transport from the continental hinterland, water- and wind-borne drift parallel to the coast and local recycling. Because of the similarity in detrital zircon distribution patterns of the sandstone and all of its potential Palaeozoic to Cretaceous sedimentary precursors, detrital zircon data cannot provide useful information on the relative importance of these processes, or on the routing of detritus to its final site of deposition.

Árvores Comuns de Moçqambique. Common Trees of Mozambique

Mozambique is a country located in southeastern Africa bordered by the Indian Ocean to the east Tanzania to the north, Malawi and Zambia to the northwest, Zimbabwe to the west, and Eswatini and South Africa to the southwest. A colored map on page 12 shows the location of the country. There are 53 families and 153 genera included in the descriptions and illustrations. The species names are given in English and Portuguese. Each taxon is represented by one description page and one color illustration page. Species descriptions are in both English and Portuguese organized by DISTRIBUTION, HABITAT, USES, and NOTES. This book will have limited use outside of the geographical area of emphasis. The Glossary, Bibliography, Index of Local Names, and General Index add value to book usage.

Lower Prevalence Countries Outside of South-Eastern Africa Now Have the Fastest Growing HIV Epidemic.

The United Nations Program on HIV/AIDS (UNAIDS) targets aim to reduce new HIV infections below 370 000 annually by 2025. However, there were 1.3 million new HIV infections worldwide in 2022. We collected and analyzed data for key variables of the HIV epidemic from UNAIDS and supplemented by PUBMED/EMBASE searches and national reports. A total of 53% of the HIV infections worldwide were in 14 high-prevalence countries in Southern/East Africa-where most of the funding for treatment and prevention is allocated-versus 47% in 54 low-prevalence countries. In 2022, there were more new HIV infections (770 000 vs 468 000), more HIV-related deaths (383 000 vs 225 000), higher rates of mother-to-child transmissions (16% vs 9%) and lower antiretroviral therapy coverage (67% vs 83%) in low-prevalence countries versus high-prevalence countries. To achieve UNAIDS annual new infections target for 2025, ART coverage needs to be optimized worldwide, and preexposure prophylaxis coverage expanded to 74 million people, versus 2.5 million currently treated.

Carbon storage in a dry Miombo woodland area in Tanzania

A persistent need exists, both politically and academically, for knowledge on carbon storage and sequestration potentials of forest ecosystems and their contributions to the global carbon balance. This study assessed carbon stocks of a 6 065 ha dry Miombo woodland site in Iringa Rural district, Tanzania. The carbon stock for each of the six pools: trees, shrubs, deadwood, herbaceous vegetation (grass and herbs), surface litter and soil were estimated. Assuming a 50% carbon share of biomass, the results showed that the aboveground carbon stocks were: 24.71 Mg C ha−1 for trees; 10.88 Mg C ha−1 for shrubs; 0.54 Mg C ha−1 for deadwood; 0.58 Mg C ha−1 for herbaceous vegetation; and 2.47 Mg C ha−1 for surface litter. Soil carbon was estimated separately for two depth ranges: 0–15 cm and 15–30 cm below the surface. These soil strata contributed 21.24 Mg C ha−1 and 8.22 Mg C ha−1 respectively. The total carbon (C) stock of the six pools was 68.64 Mg C ha−1. Considering the vast area covered by dry Miombo woodlands in Tanzania and in 10 other countries in south-eastern Africa, the carbon stock of these ecosystems is clearly tremendous, underscoring the importance of conserving them.

Orthopedic postoperative infection profile and antibiotic sensitivity of 2038 patients across 24 countries – Call for region and institution specific surgical antimicrobial prophylaxis

PurposeImproper utilization of surgical antimicrobial prophylaxis frequently leads to increased risks of morbidity and mortality.This study aims to understand the common causative organism of postoperative orthopedic infection and document the surgical antimicrobial prophylaxis protocol across various institutions in to order to strengthen surgical antimicrobial prophylaxis practice and provide higher-quality surgical care. MethodsThis multicentric multinational retrospective study, includes 24 countries from five different regions (Asia Pacific, South Eastern Africa, Western Africa, Latin America, and Middle East). Patients who developed orthopedic surgical site infection between January 2021 and December 2022 were included. Demographic details, bacterial profile of surgical site infection, and antibiotic sensitivity pattern were documented. Results2038 patients from 24 countries were included. Among them 69.7 % were male patients and 64.1 % were between 20 and 60 years. 70.3 % patients underwent trauma surgery and instrumentation was used in 93.5 %. Ceftriaxone was the most common preferred in 53.4 %. Early SSI was seen in 55.2 % and deep SSI in 59.7 %. Western Africa (76 %) and Asia-Pacific (52.8 %) reported a higher number of gram-negative infections whereas gram-positive organisms were predominant in other regions. Most common gram positive organism was Staphylococcus aureus (35 %) and gram-negative was Klebsiella (17.2 %). Majority of the organisms showed variable sensitivity to broad-spectrum antibiotics. ConclusionOur study strongly proves that every institution has to analyse their surgical site infection microbiological profile and antibiotic sensitivity of the organisms and plan their surgical antimicrobial prophylaxis accordingly. This will help to decrease the rate of surgical site infection, prevent the emergence of multidrug resistance and reduce the economic burden of treatment.

Ethnic background and distribution of clinical phenotypes in patients with probable progressive supranuclear palsy

BackgroundProgressive Supranuclear Palsy (PSP) is a sporadic neurodegenerative disease without a clear geographic prevalence. Cohorts studied in the UK and India showed no higher prevalence of atypical parkinsonism in South Asian patients. We describe the ethnic and racial background of PSP patients in the Greater Toronto Area (GTA), Canada. MethodsA prospective observational study of patients with clinically probable PSP evaluated at the dedicated Rossy PSP program. Demographic and clinical data were collected at baseline including PSP phenotype. Results were compared with the latest demographic information from the greater Toronto area. ResultsOf the 197 patients screened, 135 had probable PSP and resided within the GTA. The mean age at visit was 71.1 years, disease duration 4.4 years, and disease severity moderate. Compared to our catchment area, there was a higher proportion of patients with a South Asian origin and a lower proportion of patients from East and Southeastern Asia and Africa. A secondary analysis using population census data limited to individuals greater than 65 confirmed the significantly higher representation of South Asians in our clinic but found no differences for other racial and ethnic origins. ConclusionEvaluation of this Toronto cohort found a greater than expected proportion of affected individuals with South Asian ethnic and racial origin. Despite limitations, our results suggest the possibility of a racial and ethnic predisposition to PSP. Further studies are needed to confirm and to address potential associated risk factors, and genome-environmental interactions.

Unravelling the maternal evolutionary history of the African leopard (Panthera pardus pardus).

The African leopard (Panthera pardus pardus) has lost a significant proportion of its historical range, notably in north-western Africa and South Africa. Recent studies have explored the genetic diversity and population structure of African leopards across the continent. A notable genetic observation is the presence of two divergent mitochondrial lineages, PAR-I and PAR-II. Both lineages appeared to be distributed widely, with PAR-II frequently found in southern Africa. Until now, no study has attempted to date the emergence of either lineage, assess haplotype distribution, or explore their evolutionary histories in any detail. To investigate these underappreciated questions, we compiled the largest and most geographically representative leopard data set of the mitochondrial NADH-5 gene to date. We combined samples (n = 33) collected in an altitudinal transect across the Mpumalanga province of South Africa, where two populations of leopard are known to be in genetic contact, with previously published sequences of African leopard (n = 211). We estimate that the maternal PAR-I and PAR-II lineages diverged approximately 0.7051 (0.4477-0.9632) million years ago (Ma). Through spatial and demographic analyses, we show that while PAR-I underwent a mid-Pleistocene population expansion resulting in several closely related haplotypes with little geographic structure across much of its range, PAR-II remained at constant size and may even have declined slightly in the last 0.1 Ma. The higher genetic drift experienced within PAR-II drove a greater degree of structure with little haplotype sharing and unique haplotypes in central Africa, the Cape, KwaZulu-Natal and the South African Highveld. The phylogeographic structure of PAR-II, with its increasing frequency southward and its exclusive occurrence in south-eastern South Africa, suggests that this lineage may have been isolated in South Africa during the mid-Pleistocene. This hypothesis is supported by historical changes in paleoclimate that promoted intense aridification around the Limpopo Basin between 1.0-0.6 Ma, potentially reducing gene flow and promoting genetic drift. Interestingly, we ascertained that the two nuclear DNA populations identified by a previous study as East and West Mpumalanga correspond to PAR-I and PAR-II, respectively, and that they have come into secondary contact in the Lowveld region of South Africa. Our results suggest a subdivision of African leopard mtDNA into two clades, with one occurring almost exclusively in South Africa, and we identify the potential environmental drivers of this observed structure. We caution that our results are based on a single mtDNA locus, but it nevertheless provides a hypothesis that can be further tested with a dense sample of nuclear DNA data, preferably whole genomes. If our interpretation holds true, it would provide the first genetic explanation for the smaller observed size of leopards at the southernmost end of their range in Africa.

Ranking and developing ground-motion models for Southeastern Africa

The southern East African Rift System (EARS) is an early-stage continental rift with a deep seismogenic zone. It is associated with a low-to-moderate seismic hazard, but due to its short and sparse instrumental record, there is a lack of ground-motion studies in the region. Instead, seismic hazard assessments have commonly relied on a combination of active crustal and stable continental ground-motion models (GMMs) from other regions without accounting for the unusual geological setting of this region and evaluating their suitability. Here, we use a newly compiled southern EARS ground-motion database to compare six active crustal GMMs and four stable continental GMMs. We find that the active crustal GMMs tend to underestimate the ground-motion intensities observed, while the stable continental GMMs overestimate them. This is particularly pronounced in the high-frequency intensity measures (>5 Hz). We also use the referenced empirical approach and develop a new region-specific GMM for southern EARS. Both the ranked GMMs and our new GMM result in large residual variabilities, highlighting the need for local geotechnical information to better constrain site conditions.

Interannual Lightning Variability within the TRMM LIS Dataset Using an ENSO Perspective

Abstract The Tropical Rainfall Measuring Mission (TRMM) Lightning Imaging Sensor (LIS) was used to investigate interannual variability of lightning from 1998 to 2014 within the 38°S–38°N range. Previous studies have indicated that the El Niño–Southern Oscillation (ENSO) phenomenon is one significant contributor to interannual lightning variability, potentially the dominant mechanism on the global scale. This period of 16 years contained four warm- (El Niño), eight cold- (La Niña), and four neutral-phase ENSO years based on the oceanic Niño index. Large magnitude lightning anomalies were found during the warm phase of ENSO, with mean warm-phase anomalies of >10 flashes (1000 km)−2 min−1 in north-central Africa and Argentina. This includes a +35 flashes (1000 km)−2 min−1 anomaly in Argentina during the 2009 El Niño. In general, large-scale anomalies of thermodynamic properties and upper-atmospheric vertical motion coincided with the lightning anomalies observed in both Africa and South America. The anomaly over north-central Africa, however, was characterized by a 6-week shift in the annual lightning maximum with the warm phase, a result of the more complex environmental response to ENSO over the Sahel. The most consistent ENSO anomalies with appreciable lightning were found in southeastern Africa, northwestern Brazil, central Mexico, and the southern Red Sea. Of these, all but the Mexico region had enhanced lightning with the cold phase and suppressed lightning with the warm phase.

Structure, modulation and impacts of southeastern Africa’s diurnal convection

This study explores the structure, modulation, and impacts of the mean diurnal climate across southeast Africa using high-resolution hourly reanalysis and satellite rainfall. This research was motivated by upward trends in diurnal temperature range and vegetation index over the Drakensberg escarpment. Statistical analysis identified a land-sea rainfall dipole pattern associated with diurnal airflows. Point-to-field regressions (Oct–Mar 2000–2023) found that sea breeze-driven convection is underpinned by ‘col’ airflow between adjacent sub-tropical low-pressure cells (30°S, 20°E/22°S, 37°E) and a weak mid-latitude anticyclone (40°S, 10°E). Diurnal residual and case study analysis demonstrate an ~ 6-m/s sea breeze penetrating ~ 200 km inland during the day, as part of an over-turning zonal circulation. Land > sea rainfall during summer is initiated by temperature gradients ∂T/∂x ~ 5 °C at 29°S, 31°E and convergence in the afternoon ∂U/∂x ~ − 4 × 10−5 s−1. Further inland (29°S, 26°E) a 1007-hPa thermal low and counter-clockwise rotating airflows interact with the incoming sea breeze. Together these contribute to evening rainfall ~ 30 mm over the Drakensberg escarpment. The drivers of diurnal rainfall show little response to global climate variability, and help sustain water resources during multi-year dry spells over southeastern Africa.

Inter-Imperial Entanglement: The British Claim to Portuguese Delagoa Bay in the Nineteenth Century

Abstract: Over the nineteenth century, England and Portugal contested the possession of Delagoa Bay in south eastern Africa. Using documents from a British hydrographical survey mission of the east coast of Africa, and British Parliamentary Papers recording the dispute over possession of the bay in the 1870s, I demonstrate that bordermaking in the region was rooted in interimperial claims and disputes reaching back to the 1820s. The English claim to Delagoa Bay highlights how hydrography and cartography were used as tools of empire in the new imperial expansion and land appropriation of the nineteenth century. The production of the colonial border between Portuguese Mozambique and British South Africa interrupted and disconnected indigenous networks of relation, trade, and movement, while simultaneously entangling imperial projects of white worldmaking through racialized dispossession.

Elimination of lymphatic filariasis as a public health problem in Malawi.

Lymphatic filariasis (LF) is a parasitic disease transmitted by mosquitoes, causing severe pain, disfiguring, and disabling clinical conditions such as lymphoedema and hydrocoele. LF is a global public health problem affecting 72 countries, primarily in Africa and Asia. Since 2000, the World Health Organization (WHO) has led the Global Programme to Eliminate Lymphatic Filariasis (GPELF) to support all endemic regions. This paper focuses on the achievements of the Malawi LF Elimination Programme between 2000 and 2020 to eliminate LF as a public health problem, making it the second sub-Saharan country to receive validation from the WHO. The Malawi LF Programme addressed the widespread prevalence of LF infection and disease across the country, using the recommended WHO GPELF strategies and operational research initiatives in collaboration with key national and international partners. First, to stop the spread of infection (i.e., interrupt transmission) and reduce the circulating filarial antigen prevalence from as high as 74.4% to below the critical threshold of 1-2% prevalence, mass drug administration (MDA) using a two-drug regime was implemented at high coverage rates (>65%) of the total population, with supplementary interventions from other programmes (e.g., malaria vector control). The decline in prevalence was monitored and confirmed over time using several impact assessment and post-treatment surveillance tools including the standard sentinel site, spot check, and transmission assessment surveys and alternative integrated, hotspot, and easy-access group surveys. Second, to alleviate suffering of the affected populations (i.e., control morbidity) the morbidity management and disability prevention (MMDP) package of care was implemented. Specifically, clinical case estimates were obtained via house-to-house patient searching activities; health personnel and patients were trained in self-care protocols for lymphoedema and/or referrals to hospitals for hydrocoele surgery; and the readiness and quality of treatment and services were assessed with new survey tools. Malawi's elimination of LF will ensure that future generations are not infected and suffer from the disfiguring and disabling disease. However, it will be critical that the Malawi LF Elimination programme remains vigilant, focussing on post-elimination surveillance and MMDP implementation and integration into routine health systems to support long-term sustainability and ongoing success. Lymphatic filariasis, also known as elephantiasis, is a disabling, disfiguring, and painful disease caused by a parasite that infected mosquitoes transmit to millions of people worldwide. Since 2000, the Global Programme to Eliminate Lymphatic Filariasis (GPELF) has supported endemic countries such as Malawi in south-eastern Africa, to eliminate the disease as a public health problem. The Malawi National LF Elimination Programme has worked tirelessly over the past two decades to implement the GPELF recommended strategies to interrupt the transmission with a two-drug regime, and to alleviate suffering in patients with lymphoedema and/or hydrocoele through morbidity management and disability prevention. Additionally, the LF Programme has collaborated with national and international stakeholders to implement a range of supplementary operational research projects to address outstanding knowledge gaps and programmatic barriers. In 2020, the World Health Organisation validated that Malawi had successfully eliminated LF as a public health problem, making it the second country in sub-Saharan Africa to achieve this, which is remarkable given that Malawi previously had very high infection rates. The LF Programme now remains vigilant, putting its efforts towards post-elimination surveillance and the continued implementation of care for patients with chronic conditions. Malawi's elimination of LF will ensure that future generations are not affected by this devastating disease.

Observed trends in timing and severity of streamflow droughts across global tropics

Drought is a recurrent climatic hazard impacting natural and built environmental systems, including human lives. Although several studies have assessed streamflow droughts and their multivariate characterization, very few studies have focused on understanding spatiotemporal changes in drought attributes, such as drought seasonality, severity and duration across global tropics. Further, the nonlinear response between onset time and severity of streamflow droughts at a large scale are unknown. Leveraging ground-based streamflow observations, this study for the first time investigate changes in streamflow drought characteristics across global tropics using two 30 year climate normal periods: 1961–1990 and 1991–2020. Our analyses of changes in probability distributions of onset time and severity (deficit volume) of streamflow droughts over the two time windows show significant shifts towards higher values for Northeast and South American Monsoon region, Western Africa, eastern South Africa, north and eastern Australia. Around 55% of the sites show an increase in drought frequency in recent times. We found that in the recent times, only 27% of sites depict an increase in deficit volume accompanied by delayed onset. Further, we identify a few regional hotspots, such as Northeast and South American monsoon region, and eastern coast of Australia show an increased frequency of droughts with an upward trend in deficit volume in recent years. As expected, the individual changes in drought attributes have translated into changes in joint occurrences of their interdependent attributes, assuming the correlation between onset time and deficit volume. Our analyses show robust dependence strengths between onset time and deficit volume, which strengthen further in the recent time window over 50% of catchments. The nonstationary changes identified here in individual drought attributes and their joint dependence can alter the hazard potential of extreme droughts, which has consequences in risk management, climate adaptation and water resources planning.

Occurrence of Trace-Level Antibiotics in the Msunduzi River: An Investigation into South African Environmental Pollution.

The presence of antibiotics in the environmental matrix has raised concerns regarding their risk to the aquatic ecosystem and human health. Surface water, such as rivers, plays a pivotal role in the dispersion and transport of antibiotic residues. The effective monitoring of these contaminants requires investigating their sources and distribution. While numerous studies have been conducted globally to comprehend the emergence, prevalence, and management of these substances, the investigation of therapeutic antibiotics in Africa remains notably underrepresented. Consequently, data regarding these emerging contaminants in the African aquatic environments are scarce, warranting further exploration. This study aims to investigate the occurrence of four specific therapeutic antibiotics-tetracycline, sulfathiazole, penicillin g, and erythromycin-across different seasons in the Msunduzi River, Eastern South Africa. Three sampling campaigns were conducted during spring, autumn, and winter to assess the presence of these antibiotics in the river. Analyte extraction from water samples was achieved through solid-phase extraction, and quantification was performed using liquid chromatography-mass spectrometry. The findings reveal notable concentrations of these antibiotics in the river at locations closest to a wastewater treatment discharge point. Among the antibiotics studied, tetracycline (158.42-1290.43 ng/L) and sulfathiazole (112.68-1151.25 ng/L) were the most frequently detected compounds across the majority of the sampling sites and tributaries of the river. Erythromycin was less frequently detected in the surface water and wastewater effluent but was found to be a risk to algal species within the river. While wastewater effluents represent a significant source of antibiotic contamination in the river, tributaries from industrial areas and informal settlements were identified as continuous sources of antibiotic pollution. Thus, it is imperative to implement appropriate monitoring protocols to mitigate antibiotic pollution in the aquatic environment.