Search Results (19,297)

The recent SARS-CoV-2 pandemic—which had significant worldwide health, economic, and other effects—indicated the need to monitor zoonotic viruses with pandemic potential. The aim of this review is to assess bat-borne viruses as a potential pandemic risk, with a particular focus on Europe. The presence and activity of bats, as well as diseases emerging in humans in various regions of the world, point to their importance in the context of a possible outbreak of future epidemics. The rate of genetic change observed among viruses requires constant scrutiny on all continents, including Europe. Bats are a considerable source of many zoonotic viruses, including coronaviruses, filoviruses and paramyxoviruses. Among viruses associated with bats, RNA viruses are the dominant ones, characterized by high pathogenicity and often leading to interspecies transmission. The majority (about 80%) of RNA viruses were identified in bats from three families: Vespertilionidae, Rhinolophidae and Pteropodidae. Understanding how viruses are transmitted in the environment and the role of reservoir organisms and intermediate hosts is crucial to determining the level of epidemic risk. This review discuses viruses identified in bats globally, with a special focus on Europe, and evaluates their potential to cause epidemics. Full article

Oxidative stress and redox imbalance are central features of both age-related neurodegenerative disorders and the persistent neurological sequelae of coronavirus disease 2019. Increasing evidence suggests that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection disrupts neuronal redox homeostasis via mitochondrial dysfunction, iron dysregulation, inflammatory signaling, and the depletion of pyridine nucleotide pools. In that context, ferroptosis provides a unifying mechanistic framework linking lipid peroxidation to progressive neuronal injury. This review proposes that neuronal vulnerability might depend not only on the oxidative burden itself but also on the failure of membrane-localized antioxidant defenses. Particular emphasis is placed on the plasma membrane redox system (PMRS), a membrane-associated quinone-reducing network that can support coenzyme Q redox cycling and constrain lipid radical propagation at the plasma membrane. Unlike canonical ferroptosis defense systems that rely predominantly on NADPH, components of the PMRS, particularly cytochrome b5 reductase, can also use NADH, conferring partial metabolic flexibility in conditions of redox stress. We further discuss how SARS-CoV-2-induced NAD⁺ depletion might progressively destabilize this membrane-proximal defense architecture, potentially lowering the ferroptotic threshold of vulnerable neurons. Finally, we outline therapeutic strategies that might reinforce PMRS-dependent membrane redox control through NRF2 activation, NAD⁺ restoration, coenzyme Q-centered interventions, and modulation of iron-catalyzed lipid oxidation. Full article

The presence of wild species in urban areas is becoming increasingly common. In southern Spain, species such as wild boar cause significant damage and problems in human-dominated environments, such as peri-urban areas, sports facilities, and urban parks. Here, we used camera trapping to monitor the entry rates of ungulates (wild boar and red deer) into three golf courses located in urban areas in southern Spain. The courses are surrounded by hunting estates and other non-urban areas where species are controlled through lethal methods. Wild boars are controlled year-round, and red deer are controlled during specific hunting periods. We tested for differences during periods of normal human activity and periods of the COVID lockdown using generalised linear mixed models. We controlled ungulate raids for 2639 trapping nights, obtaining 1093 wild boar and 225 red deer independent events. During the COVID lockdown, wild boar raids on golf courses decreased significantly. Meanwhile, equivalent deer raids increased significantly during the hunting period. The results indicate that certain urban areas where control by firearms is not permitted—such as golf courses—can function as safe zones for wild species. This reserve effect is related to the structure of the urban habitat and the resources it offers in terms of security and food. Full article

Respiratory syncytial virus (RSV) imposes a substantial burden of severe acute respiratory infection (SARI), especially in young children and the elderly. Methods: We describe RSV epidemiology among hospitalized SARI patients at the Ibn Sina University Hospital Center (Rabat, Morocco) from 1 January 2021, to 31 December 2025, using multiplex PCR (BioFire^® RP2.1plus or Xpert^® SARS-CoV-2/Flu/RSV). Results: Among 4604SARI samples, RSV prevalence was 16.1% (739/4604), predominantly pediatric (88.6%, p < 0.001), with peak burden in infants <6 months (70.4% of cases, p < 0.001). Pediatric prevalence was 28.3% (655/2316) vs. 3.8% (84/2204) in adults (p < 0.001), with predominance in the elderly ≥60 years (51/1041, 4.9%). Co-infections occurred in 46.7% (310/665) of FilmArray-tested positives (total = 665), led by rhinovirus/enterovirus (198/310, 63.9%), and were significantly higher in children (48.5%, p < 0.001). RSV peaked in winter (51.6%), except for summer dominance in 2021 (52.5%), reflecting COVID-19 non-pharmaceutical intervention effects. Conclusions: These data establish Morocco’s first comprehensive RSV surveillance baseline, highlighting post-pandemic epidemiological shifts. As maternal vaccines and monoclonal antibodies emerge, these data inform optimal implementation in low- and middle-income countries (LMICs). Full article

The aim of this study was to evaluate the association between baseline clinical and CT characteristics and to identify factors associated with intensive care unit (ICU) admission in hospitalized COVID-19 patients. This retrospective study included 176 adult patients with laboratory-confirmed SARS-CoV-2 infection hospitalized at the COVID Hospital of the Clinical Hospital Center Kosovska Mitrovica during 2021–2022 (Delta and Omicron variants). Patients were divided into two groups according to intensive care unit requirement: those treated in a general inpatient ward (No ICU) and those requiring ICU admission (ICU group). Demographic and clinical characteristics, lifestyle factors, CT findings, CT severity score (CTSS) values, and therapeutic interventions were compared between groups. Of the total cohort, 113 patients (64%) were hospitalized in a general inpatient ward, while 63 (36%) required intensive care unit admission. Independent predictors of ICU admission identified in the multivariate logistic regression analysis were obesity (B = 2.96, p < 0.001), dyspnea (B = 1.51, p = 0.041), higher CT severity score (B = 0.68, p < 0.001), and lower glucose levels (B = −0.27, p = 0.014). Furthermore, for each one-point increase in the CTSS, the odds of ICU admission nearly doubled (OR = 1.97). Total CT score values above the cut-off point (15.0) demonstrated significant reliability in discriminating the need for ICU transfer in patients with COVID-19. These findings suggest that combined clinical and radiological assessment at hospital admission may facilitate early identification of patients at high risk of requiring ICU care, with the CT severity score representing the strongest radiological predictor. Full article

Background: The coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2, remains a significant threat to global health. This continued threat is due to the emergence of new variants, the immune system’s limited ability to respond, and the limited effectiveness of available treatments for all individuals. Therefore, leveraging drug repurposing, a fast and inexpensive way to find other drugs that have already been shown to be safe and efficacious, becomes useful. This study leverages ADMET profiling, network pharmacology, and molecular docking to evaluate the repurposing of Product Nkabinde for COVID-19 treatment. Methods: ADMET analysis involving the bioactive phytochemicals of PN was evaluated for pharmacokinetic appropriateness and drug-likeness. Using topological analysis, a network of protein–protein interactions was built to identify hub genes, and predicted compound targets were intersected with COVID-19-associated genes to find shared targets. Their biological importance was characterized using functional enrichment analysis. The binding affinities of PN phytochemicals against hub proteins and SARS-CoV-2 viral proteases (Mpro and PLpro) were assessed by molecular docking using AutoDock Vina. To confirm docking accuracy, co-crystallized ligands were redocked using Schrodinger 2022-1. The multi-target therapeutic potential of PN in COVID-19 was assessed using this integrative network pharmacology and molecular docking technique. Results: Molecular docking demonstrated that PN phytochemicals displayed robust and persistent binding affinities for both viral and host targets. Oleanolic acid showed the best affinity toward Mpro (−12.9 kcal/mol vs. −8.3 kcal/mol), while quercetin-3-O-β-D-(6′-galloyl)-glucopyranoside showed better binding to PLpro (−8.4 kcal/mol vs. −6.4 kcal/mol). Procyanidin B2 toward HCK (−10.5 vs. −7.9 kcal/mol), diosgenin toward EGFR (−9.4 vs. −8.4 kcal/mol), rutin toward SRC (−10.5 vs. −7.8 kcal/mol), and pimelea factor P2 toward PIK3R1 (−11.0 vs. −8.2 kcal/mol) all showed significantly higher affinities than their corresponding co-crystallized ligands. Furthermore, procyanidin B2 demonstrated consistent binding to STAT1 and STAT3, confirming its role in modulating immune signals. Most of the PN phytochemicals show advantageous pharmacokinetic properties, including elevated anticipated gastrointestinal absorption and adherence to Lipinski’s rule of five, signifying favorable oral bioavailability and drug-like properties. Moreover, PN exhibits a remarkable multi-target binding capacity against both SARS-CoV-2 proteases and key host signaling proteins involved in immune regulation and inflammatory responses, as determined by this integrative network pharmacology and molecular docking investigation. Conclusions: PN’s prospects as a host-directed, antiviral treatment for COVID-19 are demonstrated by its coordinated modulation of the PI3K/AKT, JAK–STAT, SRC-family kinase, EGFR, and SYK pathways. These results necessitate further experimental and clinical validation, providing a solid computational basis for repurposing PN in the treatment of COVID-19. Full article

SARS-CoV-2, the causative agent of COVID-19, emerged in late 2019 and rapidly developed into a global health crisis. In this study, we analysed 173,194 SARS-CoV-2 genomes from the GISAID database to explore the intra-continental dynamics and distribution of variants across Africa between 2020 and 2024. We have identified 1377 distinct lineages, which were classified by clade to assess associations with infection and mortality rate. So, we conducted a Shannon entropy analysis to confirm the diversity and we applied a Correspondence Analysis (CA). Our findings revealed that one of the deadliest in Africa during the Delta wave, lineage AY.45 predominated in the South Africa cluster, whereas AY.34.1 drove transmission in the Atlantic West Africa cluster, underscoring regional heterogeneity. Furthermore, early in the pandemic, men exhibited a 39% higher risk of infection compared to women (aOR: 1.39, 95% CI [1.34–1.45]), particularly in association with clade G. By contrast, later stages were dominated by clade GRA, which disproportionately affected the elderly (≥70 years; aOR: 1.39, 95% CI [1.33–1.45]) and children (0–9 years; aOR: 1.26, 95% CI [1.20–1.33]). Our analysis highlighted that the pandemic on the African continent unfolded as a mosaic of epidemics shaped by diverse variants and regional epidemiological contexts. These findings emphasize the importance of genomic surveillance to capture local epidemic signatures and inform region-specific public health strategies. Full article

The continued evolution of SARS-CoV-2 has enabled an escape from most monoclonal antibodies, yet a subset of broadly neutralizing antibodies targeting three newly identified super-conserved RBD epitopes—SCORE-A, SCORE-B, and SCORE-C—retains remarkable activity against even the most recent JN.1-derived sublineages. Here, we employed an integrated computational framework combining conformational dynamics, mutational scanning, MM-GBSA binding energetics, and frustration profiling to dissect the molecular mechanisms by which XGI antibodies achieve broad neutralization and resistance to immune escape. Structural analysis revealed that all three SCORE epitopes share a common architecture: a highly conserved, minimally frustrated core that provides stable anchoring, flanked by peripheral regions that accommodate antibody-specific variations. Conformational dynamics showed that SCORE-A antibodies (XGI-183) rigidify the lateral epitope while leaving the RBM partially mobile; SCORE-B antibodies (XGI-198, XGI-203) clamp the RBM apex, directly blocking ACE2; and SCORE-C antibodies (XGI-171) allosterically loosen the RBM loop, impairing receptor engagement indirectly. Mutational scanning identified a hierarchical hotspot organization where primary hotspots (e.g., K356, T500, Y380, T385) are evolutionarily constrained and minimally frustrated, while secondary hotspots (e.g., V503, Y508, S383) are neutrally frustrated and represent the principal sites of immune-driven mutations. MM-GBSA decomposition revealed that van der Waals-driven hydrophobic packing dominates binding, with electrostatic interactions providing auxiliary stabilization. Critically, frustration analysis demonstrated that immune escape hotspots reside precisely in zones of neutral frustration—”energetic playgrounds” that permit mutational exploration without destabilizing the RBD—while minimally frustrated cores are evolutionarily locked. The comparative analysis of conformational versus mutational frustration distributions revealed a unifying principle: aligned neutral frustration yields permissive, escape-prone interfaces; decoupling enables the targeting of constrained cores; and the convergence of minimal frustration in both distributions creates invulnerable interfaces. These findings establish that broad neutralization arises not from ultra-high-affinity anchors but from strategic energy distribution across rigid, evolutionarily informed interfaces, providing a roadmap for designing next-generation therapeutics that target the invulnerable cores of viral surface proteins. Full article

The COVID-19 pandemic placed unprecedented pressure on diagnostic services worldwide. The first cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the UK were confirmed on 31 January 2020, prompting National Health Service (NHS) laboratories to scale diagnostic procedures. The demand for testing rapidly exceeded historical norms for respiratory virus diagnostics, necessitating substantial government investment in consumables, assay development, and workforce expansion. This review presents a retrospective evaluation of SARS-CoV-2 diagnostic platforms deployed within the Norfolk and Norwich University Hospital (NNUH) trust and compares them with those implemented by other regional laboratories during the pandemic. It examines the molecular mechanisms, performance, scalability, and specificity of the multiple molecular testing approaches to optimise workflow based on the evolving technology. The integration of complementary platforms through a stratified testing strategy enabled high-throughput population screening while preserving diagnostic resolution for complex respiratory cases, substantially improving laboratory efficiency and resilience. The emerging diagnostic methodologies, RT-LAMP and CRISPR-based assays, are described, and we discuss their potential roles in future outbreaks. We critically evaluate the overall preparedness of UK health services for the COVID-19 pandemic and highlight key priorities for future pandemic preparedness at both local and national levels. Full article

Background and Objectives: The objective of this study was to investigate the relationship between clinical periodontal status and COVID-19 severity, including intensive care unit (ICU) admission and in-hospital mortality, in a cohort of hospitalized patients. Materials and Methods: This single-center, cross-sectional study included 44 patients with polymerase chain reaction-confirmed COVID-19 hospitalized at Buca Seyfi Demirsoy Training and Research Hospital, Izmir, Turkey, between August and December 2021. Of these, 32 (72.7%) were admitted to the ICU and 12 (27.3%) to the inpatient service. All participants underwent a full-mouth clinical periodontal examination to assess probing pocket depth (PPD), clinical attachment level (CAL), bleeding on probing (BoP), and plaque index (PI). Clinical data, demographics, comorbidities, and validated disease severity scores (GCS, APACHE II and SOFA) were extracted from electronic medical records, and a univariate logistic regression analysis was performed to identify factors associated with in-hospital mortality. Results: Patients admitted to the ICU (n = 32) were significantly older, had a higher prevalence of comorbidities, and showed higher CAL (p = 0.049) and PI (p < 0.001) values than those treated in the inpatient service. Deceased patients (n = 15) had a significantly higher PI than survivors (p = 0.024). In the univariate logistic regression analysis, APACHE II was the only variable significantly associated with in-hospital mortality (OR = 0.867, p = 0.003), however none of the periodontal parameters, including CAL and PI, showed a statistically significant association with mortality. Conclusions: Poorer periodontal findings, particularly higher CAL and PI values, were more frequently observed in patients requiring ICU care. However, periodontal parameters were not significantly associated with in-hospital mortality in univariate analysis. Given the cross-sectional design, small sample size, and lack of multivariable adjustment, these findings should be interpreted as unadjusted associations rather than evidence of an independent or causal relationship. Full article

The evolution and spatial dissemination of SARS-CoV-2 Omicron subvariants have been characterized by rapid lineage replacement and complex transmission dynamics influenced by regional connectivity. This study presents a comprehensive discrete phylogeographic analysis of 90,136 SARS-CoV-2 sequences collected in Poland from 2022 to 2024 to reconstruct the dispersal dynamics of major Omicron lineages, including BA.1, BA.2, BA.5, CH.1, XBB.1, and JN.1. Utilizing Bayesian statistical frameworks, we identified significant viral transitions between the 16 Polish voivodeships and established variant-specific dominance windows ranging from 2 to 4 months. Our findings reveal a highly dynamic epidemic landscape with shifting regional epicenters. The initial BA.1 wave was primarily driven by the Mazovian voivodeship, accounting for 36.1% of outward migration events. This pattern shifted dramatically with the rise in BA.2, which was centered in the industrial Silesian region in the south-west, a densely populated area with strong economic ties to neighboring countries, potentially reflecting a different introduction or transmission dynamic. Furthermore, the epidemic landscape continued to reconfigure during the BA.5 wave, marked by the emergence of new transmission hubs in eastern border regions such as Lublin. Subsequent lineages exhibited distinct geographic signatures: BA.5 spread broadly along the Baltic-central corridor, CH.1 was centered in the north-east, XBB.1 re-emerged in the west-central region of Greater Poland, and JN.1 was driven overwhelmingly by Lesser Poland. These transitions highlight that regional transmission hubs are transient and influenced by local factors such as population density, cross-border mobility, and socio-economic connectivity. This study underscores the critical value of dense genomic surveillance in identifying evolving dispersal routes to inform adaptive, region-specific public health interventions. Full article

A cell-based screening system for viral protease inhibitors was developed using firefly luciferase fragment complementation and validated on the SARS-CoV-2 3CLpro model. The optimal luciferase variant incorporating the VLQSGF proteolytic site (Luc III) retained 88% of its native activity. A critical requirement for system performance was the use of an extended nsp4–nsp6 fragment of the viral polyprotein rather than the mature protease, underscoring the importance of the native context for 3CLpro activity. The bicistronic construct pCAG-Luc-III-IRES-nsp4-6 enables coordinated expression of the reporter and protease, thereby increasing assay reproducibility. IC₅₀ values obtained in this system for nirmatrelvir and GC376 correlated with live-virus assay data but differed significantly from those of a cell-free FRET assay, reflecting the impact of cellular barriers. This approach combines simplicity, a standard substrate, and high reproducibility, making it promising for high-throughput screening in basic laboratory settings and adaptable to other viral proteases. Full article

Rapid antigen tests targeting SARS-CoV-2 nucleocapsid protein were essential for decentralised testing during the COVID-19 pandemic. Independent performance evaluations are essential to support regulatory approval and inform clinical implementation, particularly in resource-limited settings. This study presents a retrospective analytical and operational evaluation of two instrument-based fluorescent immunoassays (FIAs): the PCL COVID-19 Ag Rapid FIA and LumiraDx SARS-CoV-2 Ag Test. Analytical sensitivity was determined using recombinant nucleocapsid protein and viral cultures. Clinical performance was assessed using residual clinical specimens (n = 110) with RT-PCR as a reference, stratified by cycle threshold (Ct). Operational characteristics were assessed using a structured Likert framework. Overall sensitivity was 63% (51–73) for PCL and 95% (88–99) for LumiraDx. For Ct ≤ 25, sensitivity increased to 93% and 100%. Specificity was ≥97% for both. LumiraDx maintained sensitivity (83–94%) at Ct 25–30, whereas PCL did not detect any positives in this range. The limit of detection was 39 pM (PCL) and 0.6 pM (LumiraDx). Operational usability was high for both (90% PCL, 87% LumiraDx). LumiraDx showed higher analytical sensitivity across a broader viral load range, supporting primary diagnostic use, whereas PCL was limited to high viral loads. This evaluation provides a reproducible framework for rapid diagnostic assessment during emerging outbreaks. Full article

Highly mutated Omicron sub-lineages JN.1 and NB.1.8.1 harbor extensive spike changes, but their impact in preterm infants is poorly documented. We report a preterm male infant with three hospitalizations in seven weeks: severe SARS-CoV-2 ARDS at 40 days of life (DOL 40) requiring ventilation caused by JN.1.16, HCoV-OC43 infection at DOL 65, and a mild SARS-CoV-2 reinfection at DOL 87 due to NB.1.8.1, the first detection of this variant in Tunisia. Spike analysis showed a shared JN.1 backbone but distinct N-terminal and receptor-binding domain changes, supporting intra-Omicron reinfection driven by antigenic divergence and immature immunity and underscoring the value of pediatric genomic surveillance, including phylogenetic placement of case genomes within local Omicron diversity. Full article

This paper presents work on the green synthesis of the graphene quantum dots (GQDs) and carbon dots (CDs) from leaves of Erythrina caffra (E. caffra) using a simple technique to facilitate the carbonization process, from methanol and water extracts of E. caffra leaf, and their evaluation as potential antiviral agents against SARS-CoV-2. Phytochemical profiling of E. caffra leaf extracts exhibited the presence of phenols, alkaloids, steroids/terpenoids, tannins, and flavonoids. FTIR analysis confirmed the incorporation of oxygenated functional groups inherited from the phytochemicals. UV-Vis indicated the presence of secondary metabolites in both extracts and CDs. X-ray diffraction spectra confirmed the amorphous and crystalline nature of synthesized CDs (2.51 nm) from water extracts and GQDs (0.08 nm) from methanol extracts. The CDs and GQDs exhibited respective sizes of 5.5 and 4.0 nm, with a dot-like morphology, and respective zeta potential of +200.0 and −12.6 mV. The results revealed that all extracts and carbon dot formulations exhibited high cell viability (>90%), indicating excellent biocompatibility and minimal cytotoxicity at the tested concentration of 100 mg/mL per sample. The SARS-CoV-2 experiments demonstrated that extracts (MeOH, H₂O) and nanomaterials (CDs-H₂O, GQDs-MeOH) exhibited a virus suppression efficacy of 87.86 ± 4.75%, 87.95 ± 0.77%, 87.95 ± 3.08%, and 94.84 ± 0.94%, respectively. All examined samples demonstrated viral inhibition over 88%. Both extracts and their respective nanomaterials showed that a minimum of 5 μg was required to achieve 50% antioxidant species per sample. The study highlights E. caffra as a sustainable precursor for eco-friendly carbon dot synthesis as potential antiviral and antioxidant candidates. Full article