Search Results (5,753)

Background and Clinical Significance: Overlap of diabetic ketoacidosis (DKA) and hyperosmolar hyperglycemic state (HHS) in children is a rare but life-threatening metabolic emergency. The coexistence of hyperosmolality and ketoacidosis increases neurologic vulnerability and complicates fluid and insulin management. Early identification and osmolality-guided therapy are essential to prevent cerebral edema and other complications. This case describes a 5-year-old boy with new-onset type 1 diabetes mellitus (T1D) presenting with DKA/HHS overlap two weeks after influenza vaccination—an unusual temporal association without proven causality. Case Presentation: A previously healthy 5-year-old presented with progressive polyuria, polydipsia, nocturnal enuresis, fatigue, and drowsiness. Two weeks earlier, he had received the influenza vaccine. Examination revealed moderate dehydration without Kussmaul respiration or altered consciousness. Laboratory evaluation showed glucose 45.9 mmol/L (826 mg/dL; reference 3.9–7.8 mmol/L), venous pH 7.29 (reference 7.35–7.45), bicarbonate 12 mmol/L (reference 22–26 mmol/L), moderate ketonuria, and measured serum osmolality 344 mOsm/kg (reference 275–295 mOsm/kg), fulfilling diagnostic criteria for DKA/HHS overlap. After an initial 20 mL/kg 0.9% NaCl bolus, fluids were adjusted to maintenance plus approximately 10% deficit using 0.45–0.75% NaCl according to sodium/osmolality trajectory. Intravenous insulin (approximately 0.03–0.05 IU/kg/h) was initiated once blood glucose no longer decreased adequately with fluids alone and had stabilized near 22.4 mmol/L (≈400 mg/dL). Dextrose was added when glucose reached 13.9 mmol/L (250 mg/dL) to avoid rapid osmolar shifts. Hourly neurological and biochemical monitoring ensured a glucose decline of 2.8–4.2 mmol/L/h (50–75 mg/dL/h) and osmolality decrease ≤3 mOsm/kg/h. The patient recovered fully without cerebral edema or neurologic sequelae. IA-2 antibody positivity with low C-peptide and markedly elevated HbA1c confirmed new-onset T1D. Conclusions: This case highlights the diagnostic and therapeutic challenges of pediatric DKA/HHS overlap. Osmolality-based management, conservative insulin initiation, and vigilant monitoring are crucial for preventing complications. The temporal proximity to influenza vaccination remains incidental. Full article

Influenza A viruses exhibit broad host tropism, infecting multiple species including humans, avian species, and swine. Swine influenza virus (SIV), while primarily circulating in porcine populations, demonstrates zoonotic potential with sporadic human infections. In this investigation, we identified two H1N1 subtype swine influenza A virus strains designated A/swine/China/SD6591/2019(H1N1) (abbreviated SD6591) and A/swine/China/SD6592/2019(H1N1) (abbreviated SD6592) in Shandong Province, China. The GenBank accession numbers of the SD6591 viral gene segments are PV464931-PV464938, and the GenBank accession numbers corresponding to each of the eight SD6592 viral gene segments are PV464939-PV464946. Phylogenetic and recombination analyses suggest potential evolutionary differences between the isolates. SD6591 displayed a unique triple-reassortant genotype: comparative nucleotide homology assessments demonstrated that the PB2, PB1, NP, NA, HA, and NEP genes shared the highest similarity with classical swine-origin H1N1 viruses. In contrast, SD6592 maintained genomic conservation with previously characterized H1N1 swine strains, although neither of these two isolates exhibited significant intrasegmental recombination events. Through comprehensive sequence analysis of these H1N1 SIVs, this study provides preliminary insights into their evolutionary history and underscores the persistent risk of cross-species transmission at the human–swine interface. These findings establish an essential foundation for enhancing national SIV surveillance programs and informing evidence-based prevention strategies against emerging influenza threats. Full article

Avian influenza viruses are predominantly associated with waterfowl and shorebirds, and are rarely detected in other avian hosts in nature. In 2021, an H1N1 virus was isolated from a Fieldfare Turdus pilaris in Zaporizhzhia Oblast, Ukraine. A phylogenetic analysis revealed that all eight gene segments belonged to the Eurasian low-pathogenic avian influenza lineages. The highest nucleotide identity of the HA gene was observed with viruses detected in Georgia, Sweden, and Ukraine (99.11%), while the NA gene showed the greatest identity to viruses from Western Europe (99.14–99.57%). Genetic analysis of the HA cleavage site showed a sequence (PSIQSR↓GLF) that contained a single basic amino acid. No deletions were detected in the stalk region of NA gene, and no specific mutations in PB2 protein were found. However, several amino acid substitutions were identified in the HA gene (D204E, S207T, and D239G) that may affect the binding affinity to specific antibodies. The occurrence of this virus in a wild, seemingly healthy thrush indicate that additional surveillance in poorly studied ecological groups such as Passeriformes is warranted. Full article

Background: Nirsevimab, a monoclonal antibody for respiratory syncytial virus (RSV), reduces medically attended RSV infections. It was introduced in the 2023–24 RSV season. This study examined the association between caregiver vaccination (seasonal influenza vaccine (SIV), COVID-19, and boosters) and intent to immunize infants against RSV. Methods: Data from 118 caregivers with infants ≤ 8 months were analyzed. Chi-squared tests and logistic regression assessed the relationship between caregiver vaccination and intent to immunize against RSV. Results: In total, 74.6% of caregivers intended to immunize their infants against RSV. Intent was positively associated with caregiver receipt of a seasonal influenza vaccine (p < 0.001), COVID-19 vaccine (p < 0.001), and COVID-19 booster (p < 0.001). Intent was also associated with older child seasonal vaccination. Caregiver receipt of both COVID-19 vaccinations and boosters had a strong relationship with RSV immunization intent (OR 7.91 (1.90–33.0, p = 0.004)). Conclusions: Caregiver vaccination behaviors are linked to RSV immunization intent, helping physicians identify hesitant families and prepare for immunization conversations. Full article

The endemicity of H9N2 avian influenza viruses (AIVs), particularly the Y280 lineage, poses persistent challenges to the poultry industry due to the limitations of inactivated vaccines, such as interference by maternally derived antibodies (MDAs) and incomplete suppression of viral replication. This study evaluated the immunogenicity and protective efficacy of a novel recombinant turkey herpesvirus vaccine expressing the hemagglutinin gene of H9N2/Y280 (rHVT-H9/Y280) in commercial Hy-Line Brown layers with high-MDA backgrounds. In a comparative challenge study, the rHVT-H9/Y280 vaccine induced complete protection against a homologous Y280 strain challenge at 4 weeks of age, whereas commercial inactivated vaccines failed to completely block replication, showing virus isolation rates of 16.7–25%. Long-term serological monitoring demonstrated that the rHVT-H9/Y280 vaccine elicited a robust humoral response characterized by persistent maintenance of high HI titers (>8.0 log₂) up to 39 weeks post-vaccination. These findings confirm that rHVT-H9/Y280 effectively overcomes MDA interference and provides protection by inhibition of viral replication in layer chickens, making it a promising candidate for the effective control of H9N2 AIV in endemic regions. Full article

Requirements for novel effective antiviral agents against SARS-CoV-2 emphasizes the importance of robust in vitro screening platforms. We developed a test system based on spike-pseudotyped lentiviruses, carrying either luc+ or EGFP reporter genes as a payload, and a human non-small cell lung carcinoma (NSCLC) cell line, overexpressing ACE2 (H1299-hACE2). The cell origin makes our system resemble lung epithelium infection. Transmission electron microscopy confirmed that the spike glycoproteins on the pseudotyped lentiviral particles resemble native SARS-CoV-2 spike glycoproteins, thus validating their use in inhibitor screening. H1299-hACE2 cells showed significantly higher infection rate (p < 0.005) with spike-pseudotyped lentiviruses compared to parental H1299 cells, as determined by luciferase and fluorescence assays. The susceptibility of the stable H1299-hACE2 cell line to a broad panel of SARS-CoV-2 variants (Wuhan, Beta, Delta, Omicron) was assessed here for the first time in a unified experimental setting. Infection of H1299-hACE2 cells with SARS-CoV-2 induced cell fusion and syncytium formation with subsequent cell death. The developed pseudovirus-based assay was further used for assessment of the antiviral properties of derivatives of 1,7,7-trimethyl-[2.2.1]-bicycloheptane-potential spike protein inhibitors, which possess moderate activity against lentiviral particles. The H1299-hACE2/spike-pseudotyped lentivirus assay is, therefore, a reliable, high-efficiency platform for screening spike-mediated entry inhibitors. The cell line obtained during the development of the platform can be used to isolate and study new variants of SARS-CoV-2. Full article

The complement system is a key component of innate immunity, responsible for mediating the rapid clearance of pathogens and coordinating adaptive immune responses. Although complement activation is essential for effective infection control and prevention, its excessive or dysregulated function contributes to the pathogenesis of various immune-mediated disorders. Therefore, therapeutic inhibition of the overactive complement cascade, in which specific components are selectively blocked to suppress pathological activation, plays an important role in the treatment of various complement (immune)-mediated diseases. This article provides an overview of complement inhibition as a therapeutic strategy, highlighting the infectious risks associated with its use. Disruption of complement-dependent host defence mechanisms increases the risk of invasive infections (caused by encapsulated pathogens, e.g., Neisseria spp., Streptococcus pneumoniae and Haemophilus influenzae type B), which represent a significant clinical challenge. Therefore, the use of complement inhibition should not only be effective but also safe in combination with the application of all possible tools to prevent infections. Strategies, such as vaccination and antibiotic prophylaxis, are crucial to minimise these complications, despite the persistence of the risk of breakthrough infections. Furthermore, this review examines advancements in patient risk stratification, evaluates alternative preventive measures, and identifies key gaps in current clinical practice. Future directions include improving monitoring protocols, creating more selective or locally acting complement inhibitors, and implementing biomarker-driven personalised therapies that maximise benefits while reducing side effects. Full article

The overlapping circulation of influenza (Flu), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; SC2), and respiratory syncytial virus (RSV) continues to challenge clinical laboratories, particularly in settings with limited automation and fragmented healthcare coverage. This study expanded the CDC Flu-SC2 assay by incorporating a laboratory-developed test (LDT) for RSV A/B detection into a fully automated quadruplex RT-qPCR (LDRA) on the Panther Fusion^® Open Access™ system. The design, based on more than 8000 RSV genomic sequences targeting the conserved M gene, achieved optimal amplification efficiencies (97–105%) and full multiplex compatibility. Analytical assessment established limits of detection between 9.6 and 37.8 copies per reaction, absence of cross-reactivity with 30 respiratory pathogens, and inclusivity for 32 viral variants. Commutability and diagnostic performance among the LDRA, CE IVD-marked Allplex™ SARS-CoV-2/FluA/FluB/RSV, and US IVD-marked Panther Fusion^® SARS-CoV-2/Flu A/B/RSV Assays were evaluated using 405 nasopharyngeal UTM-preserved swabs. The LDRA demonstrated excellent concordance (overall agreement ≥ 98%, κ > 0.95), strong diagnostic accuracy, and reliable detection of mixed infections. This quadruplex provides a fully automated, rapid, and accurate solution for the simultaneous detection of influenza A, influenza B, SARS-CoV-2, and RSV viruses, enhancing molecular diagnostic capacity and supporting equitable, timely clinical decision-making in middle-income healthcare systems such as that of the Dominican Republic. Full article

Bacteriophages are a key ecological factor in the legume rhizosphere, controlling bacterial populations and affecting introduced inoculant strains. Despite their importance, rhizobiophage genomic diversity remains poorly characterized. We report the complete genome of a novel predicted temperate Sinorhizobium phage, AP-202, isolated from agricultural Chernozem. This siphovirus infects the symbiont Sinorhizobium meliloti. Its 121,599 bp dsDNA genome has a strikingly low GC content (27.1%), likely reflecting adaptive evolution and a strategy to evade host defenses. The linear genome is flanked by 240 bp direct terminal repeats (DTRs), and its DNA packaging follows a T7-like strategy. Annotation predicted 178 protein-coding genes and one tRNA. Functional analysis revealed a complete lysogeny module and a divergent, two-pronged codon-usage strategy for translational control. A significant part of the proteome (74.2%) comprises hypothetical proteins, with 50 CDSs having no database homologs, underscoring its genetic novelty. Complete-genome comparison shows minimal similarity to known rhizobiophages, defining AP-202 as a distinct lineage. Phenotypic analysis indicates AP-202 acts as a selective ecological filter, with host resistance being more prevalent in agricultural than in natural soils. The AP-202 genome provides a unique model for studying phage–host coevolution in the rhizosphere and is a valuable resource for comparative genomics and soil virome research. Full article

Background/Objectives: Recently, the Herpes Zoster (HZ) vaccination has been introduced, alongside influenza and pneumococcal vaccination, at age 65. Factors influencing adherence to this vaccination and its clinical benefits are not completely understood. The aim of this study was to evaluate factors influencing adherence to HZ vaccination compared to pneumococcal and influenza and to assess its clinical effect in preventing acute vascular events. Methods: A total of 1152 patients (520 males), having a birth cohort from 1952 to 1959 inclusive, was recruited, belonging to the District of Udine (N = 839) and to the ASAPs 2 and 3 of Pordenone (N = 313). For each patient, a form was compiled. Results: HZ vaccination was administered to 498 patients, influenza to 665, and pneumococcal to 742 (p < 0.0001). Among the vaccinated, 266 received the live-attenuated version, and 232 the recombinant HZ vaccine. In logistic regression, the presence of addictions, low educational level, and poor socioeconomic status were strongly associated with lower vaccine adherence. The presence of chronic diseases enhanced only pneumococcal (p < 0.001) and influenza (p < 0.001) vaccine adherence. Forty-two non-fatal acute vascular events were recorded from age 65 onwards: 14 cardiac, 20 cerebrovascular, and 8 peripheric. Only 6/493 patients experienced an event following HZ vaccination compared to 36/659 unvaccinated subjects (p = 0.0003). In Cox modeling, HZ vaccination proved to be an independent predictor in preventing subsequent acute vascular events (p < 0.001). Conclusions: The presence of pathologies does not enhance adherence to HZ vaccination while an unfavorable socio-environmental context greatly hinders it. HZ vaccination, but not influenza and pneumococcal vaccination, appears to protect against the occurrence of acute vascular events. Full article

Background/Objectives: Toxoplasma gondii (T. gondii) dense granule antigen 14 (GRA14) is a parasitophorous vacuole membrane protein that plays a critical role in the development of chronic-stage cysts. However, its potential as a vaccine antigen and long-term immunity have not been evaluated using a virus-like particle (VLP) platform. Methods: influenza matrix protein (M1)-based VLPs displaying GRA14 were generated. Female BALB/c mice were intranasally immunized with the VLP vaccine and orally challenged with lethal ME49 cysts either 10 weeks or 32 weeks after prime vaccination for short-term and long-term immunity evaluation, respectively. Results: GRA14 VLP vaccination elicited higher levels of T. gondii-specific IgG, IgG1, and IgG2a antibody responses in sera compared to non-immunized controls. Upon challenge infection, elevated IgG- and IgA-secreting plasma cells, germinal center B cells, and memory B cells were observed, and CD4⁺, CD8⁺ T-cells, as well as both Th1 (IFN-γ) and Th2 (IL-4, IL-5) cytokines, were also increased. For the short-term immunity study, vaccinated mice exhibited suppressed cerebral inflammation, significantly reduced brain cyst burdens, maintained stable body weight, and achieved 100% survival. For the long-term study, GRA14 VLPs sustained elevated IgG and IgG1 levels as well as conferred partial yet significant protection, with lower cyst loads and 83% survival. Conclusions: GRA14 VLPs induce durable, balanced humoral and cellular immunity and provide both short-term and long-term protection against lethal chronic toxoplasmosis, supporting their potential as promising vaccine candidates. Full article

Currently, in influenza vaccine production via the chicken embryo splitting method, embryo viability detection is a pivotal quality control step—non-viable embryos are prone to microbial contamination, directly endangering the vaccine batch quality. However, the predominant manual candling method suffers from unstable accuracy and occupational visual health risks. To address this challenge, we developed a novel real-time embryo viability detection system based on photoplethysmography (PPG) technology, comprising a hardware circuit for chicken embryo PPG signal collection and customized software for real-time signal filtering and time–frequency-domain analysis. Based on this system, we conducted three pivotal experiments: (1) impact of the source–detector spatial arrangement on PPG signal acquisition, (2) viable/non-viable embryo discrimination, and (3) embryo PPG signal detection performance for days 10–14. The experimental results show that within the sample size (15 viable, 5 non-viable embryos), the system achieved a 100% discrimination accuracy; meanwhile, it realized 100% successful multi-day (days 10–14) PPG signal capture for the 15 viable embryos, with consistent performance across the developmental stages. This PPG-based system overcomes limitations of traditional and existing automated methods, provides a non-invasive alternative for embryo viability detection, and presents significant implications for standardizing vaccine production quality control and advancing optical biosensing for biological viability detection. Full article

Influenza-associated encephalitis/encephalopathy (IAE) is a severe neurological complication characterized by central nervous system dysfunction and structural damage following influenza virus infection. Predominantly affecting infants and young children, IAE exhibits its highest incidence in those under five years of age. Key clinical manifestations of IAE include acute seizures, sudden high fever, and impaired consciousness, frequently progressing to coma. Neuroimaging, particularly magnetic resonance imaging (MRI), often reveals multifocal brain lesions involving multiple brain regions, including the cerebellum, brainstem, and corpus callosum. The prognosis of IAE is poor, with a mortality rate reaching 30%. Current diagnosis relies heavily on clinical presentation and characteristic neuroimaging findings, as the precise pathogenesis of IAE remains elusive. While various research models, including cell lines, brain organoids, and animal models, have been developed to recapitulate IAE features, significant limitations persist in modeling the core clinical pathophysiology observed in pediatric patients, necessitating further model refinement. This review synthesizes the clinical spectrum of IAE, summarizes progress in understanding its pathogenesis, and critically evaluates existing research models. We aim to provide a foundation for utilizing experimental approaches to elucidate IAE mechanisms and identify potential therapeutic strategies. Full article

Highly pathogenic avian influenza (HPAI) H5N1 clade 2.3.4.4b viruses spread efficiently via migratory wild birds and increasingly infect mammals. The leopard cat (Prionailurus bengalensis) is an endangered mesopredator in South Korea that frequents wetland–forest ecotones and overlaps with wild waterbirds, placing it at risk of exposure. We describe a fatal HPAI H5N1 infection in a free-ranging leopard cat detected through national wildlife surveillance during a period of widespread H5N1 activity in wild birds along the East Asian–Australasian Flyway. The animal showed acute neurological and respiratory signs and died shortly after rescue. H5 viral RNA was detected by RT-qPCR in all examined tissues, with the highest load in the brain, and infectious virus was isolated from the brain, bronchoalveolar lavage fluid, and nasal swab. Pathology revealed acute serofibrinous pneumonia, severe nonsuppurative meningoencephalitis, necrotizing vasculitis with thrombosis, and necrotizing enteritis with secondary mesenteritis. Immunohistochemistry demonstrated abundant viral antigen in nasal and olfactory epithelium, olfactory bulb, neurons, endothelial cells, and bronchial and bronchiolar epithelium, supporting combined olfactory and hematogenous dissemination. This clinicopathological description expands the spectrum of HPAI-associated lesions in felids and underscores the value of wild carnivores as bioindicators of avian influenza spillover in a One Health context. Full article

The review deals with the current knowledge on the global panzootic spread of highly pathogenic avian influenza viruses (HPAIVs), with an emphasis on the H5N1 clade 2.3.4.4b virus. It describes the viral structure, replication, pathotypes and molecular determinants of host range, including sialic-acid receptor usage and key genetic mammalian-adaptation markers (PB2-E627K and PB2-D701N mutations). The host spectrum nowadays extends from wild waterfowl and poultry including seabirds, terrestrial and marine mammals and, based largely on experimental studies or molecular detection, reptiles, amphibians, and fish. Recently, the H5N1 clade 2.3.4.4b virus has shown marked tropism for lactating mammary epithelium in dairy cattle, with virions shed in raw milk. The review reports epidemiology, geographical expansion, clinical presentation, pathogenesis and pathology, diagnosis, immune responses and vaccination approaches across species. It also analyses European Union (EU) and Italian regulatory frameworks, surveillance strategies and biosecurity measures from a One-Health perspective. The review highlights how climate change, wildlife–livestock interfaces, intensive farming and global trade favor viral persistence and genomic reassortment and concludes by stressing strategic actions to limit further host adaptation and panzootic/pandemic risks. Full article