Search Results (84)

Background/Objectives: Zoonotic tuberculosis (TB) remains a persistent public health challenge worldwide. It is particularly common in settings with close human–livestock–environment interactions. In Tanzania, progress toward TB control is increasingly threatened by multidrug-resistant tuberculosis (MDR-TB), yet genomic data from regions characterized by pastoralist and mining activities remain scarce. This study employed whole-genome sequencing (WGS) to characterize M. tuberculosis complex (MTBC) strains circulating among human and cattle populations in the Manyara region of northern Tanzania, with a focus on resistance-associated mutations and phylogenetic relationships. Methods: This cross-sectional study was conducted between September 2024 and February 2025. A total of 178 presumptive human TB cases provided sputum samples. From cattle, 161 samples were collected (110 milk samples and 51 lymph node aspirates), with each animal contributing only one type of sample. Specimen were analyzed using GeneXpert MTB/RIF, Lowenstein–Jensen culture, and WGS. Phylogenetic reconstruction was performed using SNP-based methods and IQ-TREE2 version 2.2.0. Results: Among human participants, 14 (7.8%) sputum samples were GeneXpert positive and were confirmed as members of MTBC by LJ culture. In cattle, one (0.62%) lymph node aspirate was positive for MTBC. Significant predictors of MTBC positivity included previous TB history, weight loss, and occupation involving mining and cattle keeping. WGS of five human isolates identified Lineages 1, 3, and 4. One isolate (Sample 98) harbored mutations associated with XDR-TB. Conclusions: WGS revealed M. tuberculosis Lineages 1, 3 and 4 circulating in the Manyara region, with diverse genetic mutations conferring with resistance to first- and second-line anti-TB drugs. These findings highlight the importance of integrated genomic surveillance to monitor drug resistance patterns in Tanzania and similar settings across human and animal populations. Full article

Introduction: Historically, human infections with clade Ia monkeypox virus (MPXV) primarily occurred through zoonotic transmission with limited secondary human-to-human transmission. Recent studies suggest increasing evidence of human-to-human transmission of some clade Ia lineages. This report documents the first imported clade Ia mpox case in Shanghai, representing the second documented case in China. Methods: Patient demographics, clinical profiles, epidemiological history, and close contacts were obtained through interviews with the patient and attending physicians. Clinical specimens were collected for real-time fluorescent quantitative polymerase chain reaction (qPCR) and whole-genome sequencing. Contact tracing was implemented, involving a 21-day health monitoring of close contacts. Results: The patient presented with moderate symptoms, including fever, rash, and respiratory manifestations. Genome sequencing identified the virus as clade Ia, showing 99.96% nucleotide identity to a strain from the Democratic Republic of Congo (DRC). Eight close contacts were identified with no secondary infection reported. Conclusions: This case was confirmed as an imported clade Ia mpox case originating in the DRC. The “four JOINTs” cross-agency collaborative mechanism between the CDC and customs played a significant role in effectively stopping local transmission. Challenges in remote investigation highlight the need for stronger international collaboration. Establishing an integrated “early warning-control-tracking” system, coupled with public health intervention, is crucial for reducing importation risks and safeguarding national health security. Full article

Background: Invasive Haemophilus influenzae type b (Hib) infection in children has become rare following the introduction of highly effective conjugate vaccines under national immunisation programmes. However, breakthrough invasive infections in fully immunised individuals can still occur. We report a case of invasive Hib infection presenting as epiglottitis and bacteraemia in a fully vaccinated 5-year-old boy in regional Queensland, Australia. Case presentation: The child, with no history of immunodeficiency, presented with a 3-day history of fever, progressive throat pain and reduced oral intake. Subsequent investigations revealed leukocytosis with left shift, markedly elevated C-reactive protein, and radiographic features consistent with epiglottitis. Blood culture grew H. influenzae type b. He was treated with intravenous cefotaxime and made a full recovery without complications. Immunological evaluation demonstrated Hib-specific IgG levels consistent with prior vaccinations, with normal immunoglobulin and lymphocyte profiles supporting the absence of immunodeficiency. Whole-genome sequencing of the isolate identified sequence type 6, a known circulating strain, and duplication of the capsule (cap-b) locus which has been associated with increased capsular polysaccharide production and reduced susceptibility to immune-mediated clearance. Conclusions: This case demonstrates that invasive Hib disease can occur in fully vaccinated, immunocompetent individuals and highlights the need for continued clinical vigilance. Pathogen-related factors, such as cap-b locus duplication, may reduce the effectiveness of the immune response. Despite this, immunisation can still confer partial protection, potentially contributing to the relatively mild clinical course. Ongoing surveillance and detailed microbiological investigation are essential to better understand and monitor vaccine breakthrough infections. Full article

This research presents a robust multivariate statistical framework for the non-destructive prediction of geomechanical state parameters in quartz-rich coastal sands through acoustic emission (AE) monitoring. Granular media under symmetrical compressive stress function as complex natural systems, where microscopic energy dissipation—arising from particle rearrangement and grain microcracking—radiates as transient elastic waves. To decode these stochastic processes, 24 confined uniaxial compression tests were conducted across diverse soil typologies and moisture contents (0–12%). A high-dimensional data matrix was constructed, integrating 13 geotechnical variables with 48 acoustic descriptors formulated through three distinct temporal aggregations: stage-specific, history average and weighted history average. The statistical results identify the logarithmic effective vertical stress (${\log }_{10}\left({{\mathsf{\sigma }}^{\prime }}_{\mathrm{v}}\right)$) and the cumulative axial strain ($\mathsf{\epsilon }$) as the most significant geomechanical drivers, exhibiting Pearson correlation coefficients $\left|p\right|$ ≥ 0.85 with acoustic activity. In the acoustic domain, the analysis reveals that Signal Strength (${\mathrm{S}}_{\mathrm{s}}$) and cumulative energy ($\mathrm{E}$) flux are the most reliable predictors for volumetric deformation, while the amplitude ($\mathrm{A}$), b-value ($\mathrm{b}$), and average frequency ($\mathrm{F}$) emerge as critical indicators for identifying the transition between spatial rearrangement and the onset of grain fragmentation. Furthermore, the inclusion of dimensionless parameters, particularly earliness ($\mathrm{e}\mathrm{a}\mathrm{r}\mathrm{l}$), enhances model stability by standardising waveform symmetry across varying stress regimes. High-order polynomial regression models (up to the third degree) were derived, demonstrating that the statistical complexity of acoustic signatures allows for the high-fidelity inference of the soil matrix’s initial and state parameters. This methodology establishes a unified mathematical architecture for the in situ characterisation of granular skeletons, balancing computational efficiency with predictive power in intricate geological domains. Full article

The global emergence of the avian influenza virus (AIV) H5N1 clade 2.3.4.4b since 2016 has caused substantial losses in wild bird and poultry populations, along with heightened risks of transmission to humans and other mammals. Vaccination of poultry has been a key strategy to curb the virus’s spread and mitigate its socioeconomic impact. This report describes an outbreak of high pathogenicity avian influenza virus (HPAIV) H5N1 clade 2.3.4.4b in a flock of 15,000 brown layer chickens (170 days old), all of which had received a four-dose vaccination regimen with H5N1/H5N8 commercial vaccines at 17, 50, 100, and 125 days of age. Despite this vaccination history, H5N1 infection was confirmed approximately seven weeks post-vaccination. H5N1 infection was confirmed by RT-qPCR, virus isolation, and full genome sequencing covering all eight gene segments, followed by phylogenetic and molecular analyses. Clinical signs included reduced feed intake, decreased egg production, and a cumulative mortality rate of 35% over 52 days. Hemagglutination inhibition (HI) testing with various H5 antigens revealed inconsistent antibody titers (geometric mean: 4.0 to 9.1 log2). Genetic analysis of the full-length HA and NA gene sequences further revealed strong similarity to contemporaneous H5N1 clade 2.3.4.4b strains circulating in Egypt, with multiple mutations in the HA head domain, particularly near immunogenic epitopes and receptor binding sites. These findings highlight the limitations of current vaccination strategies under conditions of antigenic mismatch and complex immunization schedules, emphasizing the need for improved vaccine matching and continuous molecular surveillance. To improve outbreak management in poultry, enhanced vaccination protocols, stringent biosecurity measures, and rigorous monitoring practices are critical. Full article

Background/Objectives: While premature ventricular contraction (PVC) burden is clearly linked to cardiomyopathy in adults, its association with ventricular dysfunction in children remains less well established. This study investigated the myocardial effects of a PVC burden greater than 5% and its potential predictive factors in a pediatric population. Methods: The study enrolled 23 children aged 5–18 years with a PVC burden >5% on 24 h Holter monitoring, who had no chronic systemic illness, congenital or acquired heart disease, or known family history of cardiomyopathy or sudden cardiac death, along with 33 age-matched healthy controls. Data on demographic characteristics, anthropometric measures, clinical findings, and laboratory results were obtained. Twelve-lead electrocardiography, exercise testing using the Bruce protocol, 24 h Holter monitoring, and echocardiographic assessments—including conventional, tissue Doppler, and both segmental and global strain analyses—were performed and compared between the patient and control groups. Results: In the patient group, left ventricular isovolumetric relaxation time (IVRT) was prolonged, and the myocardial performance index (MPI) was higher compared with the controls (p < 0.001, p = 0.004). Longitudinal strain analysis revealed a significant reduction in global longitudinal strain (GLS) (p = 0.035). In addition, significantly lower segmental longitudinal strain values were observed in the basal anterolateral, basal inferolateral, and basal anterior segments, as well as a reduction in apical two-chamber GLS (p = 0.002, p = 0.002, p = 0.003, and p = 0.014, respectively). Circumferential strain was also significantly reduced in the basal anteroseptal, basal anterior, basal inferolateral, and mid anteroseptal segments, as well as in the basal, mid, and global averages (p = 0.003, p = 0.003, p = 0.026, p = 0.003, p = 0.006, p = 0.022, and p = 0.017, respectively). PVC burden on Holter monitoring was positively correlated with the global strain values, indicating less negative strain with increasing PVC burden. Conclusions: In children with structurally normal hearts and a PVC burden exceeding 5%, TDI and strain imaging revealed subtle alterations in diastolic function and myocardial deformation despite preserved ejection fraction. These findings suggest that frequent PVCs may be associated with early myocardial alterations and highlight the potential utility of advanced echocardiographic techniques in this population. Full article

Accurately and promptly acquiring the load history characteristics of impact events on composite aircraft structures is crucial for identifying impact-induced damage and developing high-fidelity digital twin models. To address this need, we propose a method for reconstructing the impact load history on composite structures, leveraging Generalized Cross-Validation (GCV) and a Fiber Bragg Grating (FBG) pattern. An equivalent expansion technique based on discretized time-domain sparse strain sampling is developed to mitigate the local distortion of impact response signals, a common issue arising from the low sampling rates of quasi-distributed FBG. By incorporating Tikhonov regularization, the ill-posed nature of the impact frequency response matrix is effectively managed. Furthermore, an adaptive optimization method based on the GCV criterion is introduced to overcome the limitations of manually selecting regularization parameters and the associated constraints on noise suppression. The results show that the proposed GCV-based reconstruction method achieves an average peak relative error of 11.4% and an average root mean square error of 0.36 N for the reconstructed impact load, demonstrating that the proposed method synergistically enhances both the reconstruction of the overall impact load waveform profile and the precise characterization of transient details, even with low-rate sampling. This provides robust technical support for health monitoring and condition-based maintenance of composite structures. Full article

Quantitatively characterizing the dynamic evolution of fracture swarms under offset well low-frequency distributed acoustic sensing (LF-DAS) monitoring remains a significant challenge. This study proposes a physics-data dual-driven closed-loop inversion framework to address this problem. The framework consists of three core modules: (1) a fluid–solid coupled semi-analytical forward model applicable to variable-rate injection and shut-in conditions; (2) an automatic key feature identification method based on multi-scale scanning and physical polarity constraints; and (3) a dynamic inversion model for fracture swarms based on adaptive particle swarm optimization (APSO). Validation against the classical PKN model confirms that the proposed forward model accurately reproduces the fundamental fracture propagation behavior, with good agreement in fracture half-length and net pressure evolution. In synthetic inversion cases, the method successfully recovers the number of fractures, the dynamic flow rate allocation history, fracture length evolution, and the spatiotemporal strain rate response. A field application further demonstrates that three dominant fractures were generated during stimulation, reaching the vicinity of the monitoring well at 18, 27, and 46 min with corresponding spacings of approximately 21 m and 16 m. The proposed framework provides a new route for advancing LF-DAS monitoring from qualitative interpretation to quantitative dynamic inversion. Full article

To address the challenge of identifying damage in the hangers and bridge deck systems of long-span suspension bridges, this paper proposes a non-contact monitoring method based on video image recognition. This method extracts structural vibration displacement responses through video acquisition and image analysis, and combined with the strain mode change rate index, it achieves damage localization, type identification, and severity assessment. The principle of extracting displacement time-history data from video images is first elaborated, and MATLAB-based computational code is developed, including pixel tracking and time-history curve generation methods. The eigensystem realization algorithm is used to identify displacement mode shapes, which are then converted into strain mode shapes via the central difference method. The strain mode change rate and its deviation rate are proposed as damage indicators: under undamaged conditions, the curve is smooth; at damage locations, peaks appear; the distribution range of peaks can distinguish between hanger damage and bridge deck cracks; the deviation rate quantifies damage severity. The feasibility of the method is validated through finite element simulations and physical model experiments. The results show that hanger damage causes broad peaks, while bridge deck cracks present narrow peaks; the deviation rate increases monotonically with damage severity. Applied to an in-service suspension bridge, the method successfully identified hanger bending and weld cracking, with assessment results consistent with on-site inspections. This study demonstrates that the strain mode change rate analysis based on video images enables damage identification without prior knowledge of the structural health state, relying solely on the damaged state response. Offering advantages such as non-contact measurement, full-field monitoring, and no need for sensor deployment, it provides a new technical approach for the long-term monitoring of suspension bridge hanger systems. Full article

During the process of damage identification and safety-state evaluation of cable-stayed bridges, the cable tension should also be incorporated into common monitoring, which usually includes displacement and strain. However, the testing process of cable tension is complicated, and the disassembly, installation and maintenance of the cable tension meter are higher priced and difficult. To improve the efficiency of damage evaluation regarding cable-stayed bridges, information-entropy theory is introduced and the curvature entropy index of the difference in the influence line of displacement is proposed. To obtain effective data parameters for damage evaluation, first, the dynamic disturbance in the displacement time-history response is removed through variational modal decomposition, and the multi-axle effect of vehicles is regularized, so as to identify the measured influence line of displacement of cable-stayed bridges. Second, the peak value of the curvature entropy index of the difference in the influence line of displacement under varied damage degrees of stay cables is extracted to construct the inverse fitting formula of damage degree. The entropy value of the measured influence line of displacement is then substituted into a PSO-BP neural network, so as to obtain the damage degree of the corresponding position of the measured data regarding the influence line of displacement of bridges. Finally, the health status of stay cables is evaluated using the information-entropy parameters of the influence line of displacement. The theoretical model and actual data are used for testing, and the research results show that: (1) the location and degree of cable damage can be effectively located and quantified by using the curvature entropy index of the difference in the influence line of displacement, and (2) the cable health index of the cable-stayed bridge tested by actual data is 96.73%, consistent with the conclusion of on-site technical evaluation. Full article

The Hardening Soil model with small-strain stiffness (HSS) is widely adopted in the numerical analysis of deep excavations and tunneling due to its ability to capture non-linear deformation and stress-history dependency. However, the determination of its key stiffness parameters remains regionally uneven, limiting its application in distinct geological contexts. To address this gap, this study systematically analyzes the physical significance and experimental determination methods of key HSS parameters. Based on comprehensive laboratory testing, including standard consolidation, consolidated undrained triaxial, empirical correlations and quantitative normalized stiffness ratios among the three reference stiffness parameters ($E_{oed}^{ref}$, $E_{50}^{ref}$, $E_{ur}^{ref}$) and the small-strain shear modulus ($G_0^{ref}$) were established for typical soil layers in Taiyuan. Additionally, recommended values for the stress dependency exponent m were determined. The derived parameter ratios were implemented in a finite element analysis of a representative deep excavation project, where the predicted wall deflections and ground settlements showed good agreement with field monitoring data. The results demonstrate that the calibrated regional parameter system provides reliable deformation prediction and improves the transparency and consistency of HSS parameter selection. These findings not only provide a reference for HSS parameter selection in the Taiyuan region but also offer a highly applicable framework for establishing similar parameter systems in other geological contexts. Full article

HIV-1 diversified for decades within the Democratic Republic of the Congo (DRC) before spreading globally in the early 1980s. Thus, the DRC is home to some of the most ancestral and diverse HIV-1 strains. Recent serosurveys conducted from 2017 to 2019 in Kinshasa, DRC, indicated high prevalence of HIV-1, yet sequence data is lacking from this period. Given the history of circulating rare HIV-1 subtypes in the DRC, a viral whole-genome sequencing study was conducted to determine current diversity in the greater Kinshasa area. Next-generation sequencing (NGS) through metagenomic and target enrichment methods was conducted on 197 specimens collected from 2017 to 2019. A large array of HIV subtypes (A, B, C, D, F1, G, H, J, and K), circulating recombinant forms (CRF01_AE, CRF02_AG, CRF05_DF, CRF11_cpx, CRF13_cpx, CRF25_cpx, CRF 45_cpx, and CRF92_C2U), unique recombinant forms, and unclassifiable sequences were observed, with many branching in basal positions within, or outside of, many subtypes on phylogenetic trees. Incorporating these new sequences into Bayesian inference of phylogeny pushes back the dates of the most recent common ancestors of HIV-1 group M and the rare subtypes G, H, and J by between 3 and 7 years each. The DRC continues to harbor diverse and rare HIV-1 subtypes that could challenge diagnostic tests, treatments, and vaccines. In addition to shifting subtype emergence dates, the sequences from our study are evidence that rare strains continue to circulate and should be regularly monitored. Full article

Background/Objective: Human papillomavirus (HPV) represents the most widespread sexually transmitted infection globally, with high-risk strains such as HPV16 driving a rising incidence of oropharyngeal squamous cell carcinoma (OPSCC), particularly in developed countries like the United States and United Kingdom. In the U.S., HPV16-associated OPSCC has surpassed cervical cancer as the most common HPV-related malignancy. Despite the availability of preventive vaccines, uptake remains suboptimal among adolescents and shifting sexual behaviors have contributed to increased disease burden. Early detection remains a major clinical challenge due to the absence of defined precursor lesions and the extended latency between viral exposure and disease onset. Most patients present with advanced-stage disease and no prior clinical history of pre-malignancy, limiting access to early-stage samples and hindering biomarker discovery. Methods: To address these limitations, we developed an in vitro HPV16 oral cancer model, using the three-dimensional organotypic raft culture system that simulates the progression of HPV16-transfected oral epithelium from precancerous states to malignant phenotypes. Results: Using HPV16-transfected human tonsil keratinocytes, we generated stratified and differentiated epithelia that mimic the biochemical and structural changes observed in vivo. This system enables detailed monitoring of epithelial differentiation, biochemical shifts, viral genome status, and key oncogenic and metabolic markers associated with HPV16-driven OPSCC. By aligning expression profiles with clinical datasets, we validated the model through the measurement of virologic markers linked to infection and progression, as well as tissue markers indicative of carcinogenic transformation. Conclusions: This model offers a promising tool for refining early detection strategies and evaluating potential clinical biomarkers, ultimately aiming to improve diagnostic precision and therapeutic outcomes in HPV-associated OPSCC. Full article

For several years, Infantis was the most common Salmonella serovar circulating in the Belgian broiler sector and persisting on broiler farms. To gain insight into its prevalence and circulation on broiler farms in Belgium, five farms (14 flocks) with a S. Infantis contamination history were monitored during two consecutive production rounds. In total, ten sampling events were conducted using moist sponge sticks after cleaning and disinfection, during the delivery of the one-day-old chicks and during production until slaughter or until positive for S. Infantis. Salmonella presence on samples was determined based on the ISO 6579:2017 standard, and the isolated strains were typed using PFGE. The results showed that current cleaning and disinfection practices were unable to completely remove S. Infantis from the farms. Cleaning equipment (3 out of 9 sample times) and the floor (5 out of 10 sample times) were particularly contaminated. Furthermore, external environmental samples were also frequently contaminated (e.g., mortality containers, concrete driveway). During production, 12 of the 28 sampled flocks were colonized with S. Infantis after one week, indicating that S. Infantis quickly spreads throughout the broiler house, which raises the hypothesis that feeding and/or drinking water systems play a critical role in the circulation of the bacteria. This study gives insights into the circulation and difficulty of controlling S. Infantis in persistently contaminated broiler farms, highlighting the importance of thorough cleaning and disinfection and biosecurity. Full article

Background/Objectives: It is unclear whether assessment of phasic atrial function could improve risk stratification for new-onset atrial fibrillation (AF) in patients with newly diagnosed cardiac sarcoidosis (CS). We aimed to investigate the prognostic value of left atrial (LA) phasic dysfunction by cardiac magnetic resonance (CMR) for new-onset AF in newly diagnosed patients with CS. Methods: 78 patients with CS, without a prior history of AF, were studied using CMR feature tracking. Over a 4-year follow-up period, AF was documented by Holter monitoring and interrogation of intracardiac devices. Clinically silent CS was defined as CS in patients with biopsy-proven extracardiac sarcoidosis, with no cardiac symptoms, but with abnormalities on CMR or positron emission tomography consistent with CS. Results: Patients with clinically manifest CS were younger (mean age 56 vs. 51 years, p = 0.018), had poorer ventricular function, higher extent of atrial late gadolinium enhancement and significantly lower LA reservoir, conduit and booster function compared to patients with clinically silent CS. Over a 4-year follow-up period, 39% of patients with clinically manifest CS and 29.7% of patients with clinically silent CS developed AF. LA reservoir strain was a strong predictor of AF in the entire cohort. In subgroup analysis, age (HR 1.30, 95% CI 1.02–1.65, p = 0.030) and LA reservoir strain (HR 0.63, 95% CI 0.44–0.90, p = 0.011) were independent predictors of AF in patients with clinically silent CS, whereas baseline NT-proBNP (HR 1.003, 95% CI 1.001–1.006, p = 0.017) predicted AF in patients with clinically manifest CS. Conclusions: Reduced LA reservoir strain on CMR predicts new-onset AF in patients with newly diagnosed CS. The predictive value of LA reservoir strain is strongest in clinically silent CS and decreases with disease progression in clinically manifest CS. Full article