Search Results (4,241)

Background and Objectives: Healthcare workers are at heightened risk of SARS-CoV-2 infection. Understanding the duration and protective value of vaccine-induced immunity is critical to inform booster strategies. This study investigates longitudinal dynamics of anti-SARS-CoV-2 receptor-binding domain IgG (anti-RBD IgG) antibodies and their association with infection risk among vaccinated healthcare workers. Materials and Methods: A prospective cohort study was conducted at Vilnius University Hospital Santaros Klinikos, Lithuania. A total of 1778 healthcare workers who completed a primary COVID-19 vaccination series were followed. Blood samples were collected every three months to measure anti-RBD IgG levels. Participants also received up to three booster doses. COVID-19 was identified by PCR, antigen tests, or positive anti-nucleocapsid IgG. For serologically detected cases, infection timing was assigned to the interval between study visits. Antibody dynamics were analyzed across vaccination stages, time, age groups, and circulating SARS-CoV-2 variants. Results: Anti-RBD IgG titers peaked in the first quarter after primary vaccination (mean 7904 AU/mL), declined sharply by quarters 2–3, and rose substantially after booster doses. Following the first booster, titers increased to ~12,598 AU/mL in quarter 1 and continued rising through quarter 3. The highest levels were observed after the second booster (24,456 AU/mL in Q1), followed by gradual decline. A high-titer plateau persisted from quarters 6 to 9 (~21,000 AU/mL), followed by decline in quarters 10–11 and partial rebound in Q12. Approximately 49.6% of participants experienced COVID-19 during follow-up. Antibody response patterns were similar across age groups, with only minor transient differences. Conclusions: COVID-19 booster doses significantly enhance and prolong humoral immunity in healthcare workers compared with the primary vaccination series. However, antibody waning over time emphasizes the need for timely boosters, particularly during periods of variant circulation. These findings support continued booster vaccination and monitoring of long-term immune protection, although anti-RBD IgG should be interpreted as a surrogate marker of humoral rather than overall immunity. Full article

Wastewater surveillance emerged as a critical public health tool during the COVID-19 pandemic, enabling early detection of community-level pathogen circulation independent of clinical testing. Its ability to capture signals from both symptomatic and asymptomatic individuals highlighted the importance of optimizing sampling methodologies to improve sensitivity and reliability. A key question is whether the several-fold increase in SARS-CoV-2 detectability observed when using passive tampon swab sampling compared with paired grab samples also applies to other respiratory viruses, including influenza A (including its avian influenza H5N1 subtype), influenza B, and respiratory syncytial virus (RSV). We collected 24 h passive swab samples with same-day grab samples from Detroit sewersheds, concentrated and purified nucleic acids, and using RT-ddPCR, quantified respiratory syncytial virus, SARS-CoV-2, influenza A, influenza B, and H5N1 influenza A viruses using markers RSV, SC2, InfA, InfB, and H5, respectively. Samples testing positive for H5 (marker for H5N1 influenza A) were further analyzed by targeted PCR and amplicon sequencing. Across three sites, median 24 h swab:grab ratios of virus copies were 7.0 for RSV, 9.2 for SC2, 9.9 for InfA, and 3.6 for InfB. A 239 bp hemagglutinin sequence from a sample with a strong H5 signal (795 copies/10 mL) had 100% identity to avian influenza viruses from Canada geese. Twenty-four-hour swab sampling greatly improves viral detectability across diverse targets and enabled the first confirmed detection of H5 in Detroit wastewater. Combined with magnetic bead purification, the overall sensitivity gain over conventional PEG-NaCl-Qiagen methods is approximately 36-fold, enabling earlier warning of community pathogens than grab samples. By integrating 24 hour passive swab sampling with high-efficiency nucleic acid purification, we expand the sensitivity of wastewater surveillance to enable detection and confirmation of low-abundance pathogens like avian influenza (H5). Full article

Background: Hematological patients have a high risk of developing severe COVID-19 (37%). Most mRNA vaccine trials in hematological patients showed a low immunogenicity after two doses, while long-term data are scarce. Methods: In this monocentric retrospective observational study, we evaluated humoral and T cell-mediated immune responses in 230 hematological patients after three doses of the Pfizer-BioNTech mRNA COVID-19 vaccine. Patients were stratified by age, disease type/state, prior COVID-19 infection, and treatment status and regimens (anti-CD20 monoclonal antibodies, BTK and BCL-2 inhibitors, and treatment line). Antibody titer to SARS-CoV-2 was assessed by electrochemiluminescence immunoassay and T cell response by QuantiFERON interferon-γ release assay (IGRA). Data were analyzed using univariate (Fisher’s exact test) and Firth’s bias-reduced penalized-likelihood logistic regression. Results: A robust humoral response was observed with 91.55% of patients developing anti-spike antibodies (GMT 988.83 U/mL). Anti-CD20-bendamustine treatment was associated with a significantly lower antibody positivity compared to untreated subjects. Prior COVID-19 infection significantly boosted both antibody positivity (95.9% vs. 85.2%) and GMT (847.02 U/mL vs. 258.79 U/mL). Conversely, T cell response was suboptimal (36.1% positive), particularly in anti-CD20-bendamustine-treated and multi-treated patients (27.1%), but highest in those treated with BTK inhibitors (50%). Multivariable logistic regression analysis linked multiple treatments to lower T cell response. Following vaccination, 29.1% of patients contracted SARS-CoV-2, but only 0.89% developed severe COVID-19. Conclusions: Three doses of mRNA vaccine elicit a strong humoral but a low T cell response, as detected by IGRA, in hematological patients. These findings underscore the importance of completing vaccination before initiating immunosuppressive therapies. Full article

This paper investigates whether water-related climate stress predicts tail movements in food system assets and whether these spillovers vary across market regimes and investment horizons. Using daily data from January 2012 to January 2026, we examine the relationships among a water-risk proxy, agricultural commodities, agribusiness, and food supply-chain equities, and a fertilizer-related proxy. The analysis combines the cross-quantilogram with quantile spillover analysis in the frequency domain, allowing us to capture directional dependence in the tails of the distribution and short- and long-run connectedness. To account for structural change, we employ data-driven break detection and identify three major regimes: a pre-disruption period, a COVID-related adjustment phase, and a broader food system stress regime from early 2022 onward. The findings indicate that water-related climate stress has its strongest predictive power in the tails, especially for agribusiness and fertilizer-related assets, while the broad agricultural commodity basket is comparatively less sensitive. Lower-tail dependence is predominantly negative and often significant, whereas upper-tail dependence is generally positive, indicating asymmetric transmission under extreme market conditions. The spillover results further show that connectedness in the water–food system is mainly short-run, with agribusiness and fertilizer channels acting as the primary conduits of transmission. From a practical perspective, these findings suggest that investors and risk managers can use water-related market signals as early warning indicators of stress in food system assets, while policymakers can strengthen food system resilience through integrated water management, input market monitoring, and supply chain adaptation measures. The findings suggest that water-related climate stress is not merely an environmental constraint but a systemic source of food system risk with implications for resilience, risk monitoring, and integrated water-agriculture governance. Full article

Background/Objectives: The coronavirus disease 2019 (COVID-19) pandemic profoundly disrupted global respiratory virus circulation, with sharp declines during 2020–2021, followed by a resurgence after the relaxation of public health measures. In South America, post-pandemic respiratory virus dynamics remain insufficiently characterized, particularly in ecologically diverse regions. Arequipa, a high-altitude city in southern Peru, has unique environmental conditions, including marked seasonal temperature variability, that may influence viral transmission. Methods: We performed a cross-sectional analysis of 21,784 nasopharyngeal swabs collected from symptomatic patients at four major hospitals between June 2021 and September 2023. All samples were tested for SARS-CoV-2 by RT-qPCR. Because routine screening for other respiratory viruses was implemented only in SARS-CoV-2-negative cases during the study period, a subset of SARS-CoV-2-negative samples was subsequently analyzed for influenza A virus (IAV), influenza B virus (IBV), and respiratory syncytial virus (RSV) using VIASURE assays. Viral circulation patterns were evaluated by year, month, and epidemiological week. Meteorological data were obtained from the SENAMHI–La Pampilla station. Logistic regression models were used to assess epidemiological and climatic predictors of viral detection. Results: SARS-CoV-2 positivity declined from 20.0% in 2021 to 8.8% in 2023. Conversely, detection of other respiratory viruses among SARS-CoV-2-negative samples increased from 0.8% in 2021 to 29.0% in 2023 (p < 0.01). Temporal increases in detection were observed during 2022–2023, particularly for IAV and RSV. In exploratory analyses, calendar year and relative humidity were associated with IAV and RSV detection, while age and temperature variables were associated with IBV. Conclusions: Climatic and demographic variables were associated with changes in viral detection for IAV, IBV, and RSV during the post-pandemic transition period in Arequipa. These findings describe patterns of viral detection within SARS-CoV-2-negative symptomatic patients and should be interpreted as surveillance-based observations rather than population-level estimates. Strengthened integrated epidemiological and genomic surveillance will be essential for vaccine planning and outbreak preparedness in the post-pandemic era. Full article

Background: Human rhinoviruses (HRVs) exhibit a global circulation characterized by prolonged epidemics and a less concentrated seasonal distribution compared with other respiratory viruses. In this study, we describe the timing, amplitude and duration of HRV epidemics on a global scale, analyzing seasonal patterns in relation to geographic latitude. Methods: HRV surveillance data reported to WHO FluNet from 2016 to 2025 were analyzed. Epidemic peak timing, amplitude and duration were estimated as a function of geographic latitude using harmonic analyses, with a comparison between the pre-pandemic (2016–2019) and post-pandemic (2021–2025) periods. Results: During the study period, 432,399 HRV detections were reported to WHO FluNet across 50 countries. Among these, 24 countries met the predefined criteria for seasonal analysis. Epidemic peak timing showed differences consistent with latitude, with peaks occurring in late autumn and winter in the Northern Hemisphere, during the central months of the year in the Southern Hemisphere, and greater temporal variability in the intertropical belt. Peak amplitude showed marked heterogeneity across countries (median 68.2%, range 28.1–96.7%), while epidemic duration indicated prolonged circulation (median 31 weeks, range 5–48 weeks). A secondary seasonal peak was identifiable in most countries, further supporting the relatively diffuse seasonal profile of HRV circulation. Comparison between the pre- and post-pandemic periods showed largely stable peak timing in most countries, alongside heterogeneous changes in peak amplitude. Conclusions: HRV is characterized by prolonged and weakly concentrated seasonal activity, with epidemic circulation often extending over several months. Despite major epidemiological perturbations during the COVID-19 pandemic, the timing of seasonal peaks remained largely stable across countries, highlighting the epidemiological resilience of HRV and the need for continuous, pathogen-specific surveillance. Full article

Background/Objective: This study is a cross-sectional investigation of long-term immune responses measured at different time intervals after COVID-19 infections, vaccinations, or combined exposure. The focus is on immune reactivity against recombinant spike (S) and nucleocapsid (N) protein antigens. Materials and Methods: Serum antibody levels were assessed up to four to four and a half years after infection or immunization, including virus-specific immunoglobulin G (IgG), IgA and IgM antibodies, as well as neutralizing antibodies against the S-protein. Cellular immunity was assessed by analyzing peripheral blood mononuclear cells (PBMC; n = 43 in first cohort, n = 32 in second cohort), including T-helper memory and cytotoxic subsets, and cytokine production after in vitro stimulation with recombinant SARS-CoV-2 proteins. A multiplex cytokine assay was used to analyze effector and regulatory immune responses. Results: Virus-specific IgG antibodies persisted for years after exposure to SARS-CoV-2, with IgG against the receptor-binding domain (RBD) correlating most strongly with neutralizing activity. Vaccinated individuals demonstrated higher IgA responses, whereas antibodies to the N-protein were associated with previous infection. No IgM antibodies were detected in any subjects, suggesting an immune response based on memory rather than ongoing infection. PBMCs from individuals with a history of both COVID-19 exposure and vaccination exhibited enhanced responsiveness, characterized by increased frequencies of memory T cells compared to vaccination alone. Stimulating with the S-protein induces higher cytokine production, including IFN-gamma, TNF-alfa, and IL-12(p70), compared with stimulation by the N-protein. Cytokines such as IL-10 and TGF-beta are also elevated, suggesting immune regulation rather than persistent inflammation. Conclusions: SARS-CoV-2 infection and vaccination are associated with persistent humoral and cellular immune responses detectable several years after exposure. Individuals with hybrid immunity exhibit broader and functionally enhanced immune reactivity, indicating more robust long-term immune memory. Future studies should focus on the long-term consequences of hybrid immunity and optimize other vaccine strategies, including recombinant antigen vaccines. Full article

Background and Objective: The aim of this study is to describe the frequency of newly detected dysglycemia, including hyperglycemia and newly diagnosed diabetes mellitus, among hospitalized COVID-19 patients without previously known diabetes and to identify associated clinical and therapeutic factors, in an exploratory, descriptive manner. Materials and Methods: We conducted a retrospective study on 562 COVID-19 patients. Demographic and clinical data were collected at admission and during hospitalization. Newly diagnosed diabetes mellitus was defined based on plasma glucose values meeting international diagnostic criteria during hospitalization in patients without prior diabetes, while newly altered blood sugar referred to transient hyperglycemia or impaired fasting glucose not fulfilling diabetes criteria. Comparisons between groups were performed using appropriate statistical tests, with a p-value < 0.05 considered statistically significant. Results: Out of the total number of 562 COVID-19 patients, 14 (2.49%) were classified as having newly diagnosed diabetes, and 27 (4.8%) as having newly altered blood sugar levels. The median age of the participants was 67.5 years (interquartile range: 59.75; 71.75). Newly diagnosed diabetes was more frequently observed among patients presenting with gastrointestinal symptoms, elevated inflammatory markers, and those receiving specific in-hospital treatments. Newly altered blood sugar levels were more commonly associated with dyslipidemia, respiratory symptoms at admission, oxygen therapy, and selected COVID-19 treatments. COVID-19 vaccination status was descriptively stratified by admission period. Conclusions: New interdisciplinary approaches may support the identification and monitoring of glycemic alterations in hospitalized COVID-19 patients, with potential implications for clinical management and public health strategies. Full article

SARS-CoV-2 is a zoonotic virus with a proven ability to infect various animal species, including domestic cats. In the post-pandemic period of COVID 19, limited data still exist on the clinical course, shedding of infectious virus and diagnostic features in cats. The aim of this study was to investigate the spread of SARS-CoV-2 in cats in 2023, the clinical manifestations of the infection, the diagnostic algorithm, including molecular detection of viral components, the differential diagnosis of co-infection with FHV, FCV, Mycoplasma spp. and Chlamydia felis, serology, and the isolation of infectious SARS-CoV-2. The immunomodulatory therapy in animals with a standalone SARS-CoV-2 infection was applied. The study included oropharyngeal, conjunctival and nasal swab samples from 102 domestic cats with clinical signs. Of them, 20.6% (21/102) were positive for SARS-CoV-2, with 16.67% (17/102) of the cats showing various variants of co-infection with FHV, FCV, Mycoplasma spp. and Chlamydia felis. Four of the cats had a standalone SARS-CoV-2 with mild clinical manifestations that included serous discharges from the eyes, without change in the general condition. The virus was isolated from these samples. These four cats and their owners were positive for antibodies to the virus, and the owners were PCR-negative. The treatment of SARS-CoV-2 infection included the preparations Viusid, RX immunosuport, Vetomun and Lisymun. This is one of the first post-pandemic studies covering FHV, FCV, Mycoplasma spp. and Chlamydia felis in domestic cats with SARS-CoV-2 infection and further expands on the essential main idea including the specified pathogens of interest. Full article

Infectious disease outbreaks continue to pose a significant threat to global health, underscoring the importance of timely detection and reliable reporting for effective interventions. Traditional reporting systems often rely on hierarchical data flows, which introduce delays, inconsistencies, and vulnerabilities, as highlighted during the COVID-19 pandemic. Blockchain, a disruptive technology, offers a promising solution. This study proposes a blockchain-based infectious disease reporting system built on Hyperledger Fabric that supports multi-level reporting and governance across national health systems. The architecture preserves hierarchical structures while enabling real-time reporting across authorized health stakeholders. It separates public test results from sensitive patient information, with private data secured via Private Data Collections and anchored using cryptographic hashes. Smart contracts enforce role-based access and validation, ensuring data integrity and controlled oversight. The system prototype was deployed within Docker containers and evaluated using illustrative COVID-19 case data. Network performance was benchmarked using Hyperledger Caliper, measuring throughput, latency, and resource utilization. The results demonstrate proper system functioning and stable transaction processing under the tested experimental conditions, supporting the feasibility of the proposed architecture for privacy-preserving multi-level infectious disease reporting systems. Full article

The impact of skin pigmentation on the accuracy of optical biomedical devices has gained increased attention since the COVID-19 pandemic, particularly following evidence of oximetry measurement bias in dark-skinned individuals. Meanwhile, many computational models utilising the Monte Carlo (MC) technique have been developed as a cost-effective and scalable method for investigating these effects. Hence, this review explores the application of the MC technique in modelling skin pigmentation, focusing specifically on how melanin in the epidermis is represented across different studies. First, the biological mechanisms of pigmentation and current stratification methods are outlined to contextualise the variability in skin tone, followed by the principles of MC modelling, including photon scattering, absorption, reflection, and detection. Following a screening and exclusion process, 50 studies were evaluated in terms of how melanin concentration and distribution are incorporated into MC models and their applications, revealing a range of approaches that include analytical equations, experimental optical property measurements, or hybrid methods. The benefits and limitations of each approach is discussed, in addition to emerging advancements such as heterogeneous melanin distribution and the relation between optical properties and skin colour classification scales. Overall, the review outlines the current methodological approaches utilised for skin pigmentation modelling and offers a reference framework for researchers seeking to improve the representation of skin pigmentation in MC-based optical simulations. Full article

Along with the coronavirus pandemic (COVID-19), some in the medical publication industry have observed an “infodemic”, which is more pandemic than the virus. Given the lack of sufficient pandemic preparedness measures in many countries, people started posting millions of posts on social media without questioning their veracity or accuracy, particularly within Arabic-speaking communities. This study investigates an unsupervised model for detecting fake news in Arabic to fight the infodemic. While there has been much research on fake news detection (FND) in English, this subject in Arabic has yet to be investigated enough in the literature. We examine the use of distribution-based clustering techniques for Arabic FND and show their performance compared to each other. Moreover, we conduct a comprehensive linguistic analysis, identifying significant differences in textual features between real and fake posts, which can improve fake news detection. Our research shows the potential of online learning techniques to enhance model performance, leading to high accuracy, reaching up to 92%. By addressing the unique challenges posed by Arabic-language posts, our research offers practical implications for developing effective strategies for reducing infodemics and their social consequences and for strategic planning to control the current and future infodemics. Full article

Background: The emergence of alternative methods of obtaining groceries since the COVID-19 pandemic has raised new concerns regarding food safety. In this study, we sought to evaluate these concerns by evaluating how the procurement method of ground beef impacts the microbial load in the beef, as this has not been thoroughly studied. Methods: Specifically, we compared beef samples obtained from in-store shopping, grocery delivery, and meal kit delivery services to determine if these new, more convenient methods of grocery shopping impact the total microbial load or Escherichia coli present in the beef. We homogenized a total of 65 beef samples and plated dilutions on trypticase soy agar, MacConkey agar, and CHROMagar. Results: We found that in-store samples had the highest microbial load with an average of 5.06 log CFU/g, while grocery delivery samples resulted in an average of 4.76 log CFU/g and meal kit samples had an average of 4.23 log CFU/g when plated on TSA. This represents a 6.7-fold change between in-store samples and meal kit samples. These differences were not statistically significant (p = 0.1, ANOVA). When plated on MacConkey agar, in-store samples had a bacterial count at 3.0 log CFU/g, while grocery delivery samples had 2.99 log CFU/g and meal kit delivered samples had 3.05 log CFU/g. Suspected E. coli O157 colonies were detected using CHROMagar plates, as these plates function to change the coloration of positive E. coli O157 colonies to pink. Suspected E. coli O157 colonies were observed in three in-store samples, two grocery delivery samples, and one meal kit sample. After confirmatory agglutination testing, one meal kit sample was confirmed as E. coli O157. Conclusions: While trends suggest possible lower microbial contamination in delivery methods versus in-store shopping procurement, no statistical significance between methods was found. These findings indicate no significant changes in microbial loads in delivered ground beef, and the high variance suggests that all procurement methods still pose some level of risk. Full article

Background/Objectives: Breast cancer is one of the most prevalent cancers among women, with notable increases among women younger than 50 years. Knowledge about breast cancer and preventive measures (e.g., early detection) are key to reducing breast cancer morbidity and mortality. Many graduate students fall within an age range when breast cancer risk starts to rise. However, research focused specifically on graduate students’ breast cancer knowledge and practices of preventive measures are sparse. Methods: This scoping review aims to synthesize the literature on breast cancer knowledge and practice of preventive measures among graduate students in a global context. Four databases (PubMed, CINAHL, APA PsycINFO, Embase) were searched for articles published between 2014 and 2024, and the following inclusion criteria were applied: full-text peer-reviewed articles available online; target population includes graduate students aged 20 to 50 years; English language; and, cross-sectional, cohort, case–control, ecological, and experimental/intervention studies. Two reviewers independently conducted article screening and data extraction using Covidence. Results: Sixteen studies met the selection criteria. Knowledge of breast cancer was examined in 94% (15/16) of the included studies and 75% (12/16) of the studies assessed practice of prevention measures (e.g., breast self-examination) among graduate students. Overall, most studies reported poor knowledge and limited uptake of prevention practices. Educational background (e.g., years of education, academic discipline and GPA), access to healthcare services, and other socioeconomic characteristics were commonly reported factors significantly associated with breast cancer knowledge and practice of preventive measures in graduate students. Conclusions: These findings may inform targeted educational interventions to increase knowledge and promote the early detection and prevention of breast cancer among graduate students. Full article

Following the COVID-19 pandemic in 2020, there has been growing interest in investigating the transmission routes of SARS-CoV-2 and identifying the potential reservoirs in wildlife. To date, the virus has been detected in a wide range of wildlife animals. SARS-CoV-2 has also been demonstrated to have the ability to infect dogs, raising concerns that other carnivores, such as free-living canids, might serve as a potential source of infection. The aim of this study was to investigate the presence of specific IgG antibodies against SARS-CoV-2 in golden jackals (Canis aureus) and red foxes (Vulpes vulpes) in Serbia. A total of 165 individuals from ten districts, including the City of Belgrade, were collected and examined from the beginning of August 2024 to the end of March 2025. Of this number, 17 samples were positive (17/165), which represents 10.3% of all the specimens tested. Among 83 red foxes, antibodies against SARS-CoV-2 were detected in 11 animals (13.3%), whereas reactive sera were identified in 6 of 82 jackals (7.3%). The analyses were performed using a commercial multi-species ELISA (IDVet, France), with the results confirmed by an in-house ELISA, previously developed for the detection of COVID-19 in humans and adapted for canids. Our findings confirm that wild animals are indeed exposed to SARS-CoV-2 infection, and that golden jackals and red foxes may represent a potential threat to human health. These results represent the first detection of SARS-CoV-2 seroconversion in wild carnivores in Serbia, highlighting the need for further surveillance and investigation. Full article