Search Results (1,886)

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/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

The onset of the COVID-19 pandemic prompted the rapid development and deployment of novel strategies and methodologies to manage the dissemination of microorganisms. Understanding the crucial role that contaminated surfaces play in the spread of viruses highlights the importance of having effective cleaning and disinfection protocols in place for inanimate objects. A variety of antimicrobial agents have shown strong effectiveness against the SARS-CoV-2 virus. Various factors can impact on the performance of these agents. As a result, technologies utilizing ozone’s microbicidal effects have been developed or improved for cleaning indoor areas, surfaces, and materials, despite ozone’s diverse uses being known for years. Ozone offers the advantage of adaptability for both gaseous and aqueous use, depending on the nature of the decontaminated surfaces. Moreover, ozone-infused water is ecologically benign, possesses microbial-fighting capabilities, and synergistically reinforces the biocidal action of other chemical disinfectants. This review aims to summarize the efforts dedicated to harnessing gaseous and aqueous ozone as a valuable means to eliminate the SARS-CoV-2 virus from environments, surfaces, clinical equipment, and office supplies. This review sourced evidence-based articles from electronic databases, including MEDLINE (via PubMed), EMBASE, the Cochrane Library (CENTRAL), and preprint repositories. The findings illustrated that ozone could serve as an additional tool for curbing the proliferation of COVID-19 and other viral infections. Additionally, we elucidated the operational attributes of ozone, the variables that influence its disinfection potency, and the mechanisms of its virucidal action. Notably, this review does not encompass the disinfection of the COVID-19 virus in wastewater. Full article

Background: Molecular diagnostics may detect several respiratory pathogens simultaneously with rapid turnaround times. The aim of this study was to determine the frequency and distribution of respiratory pathogens among symptomatic outpatients. Methods: All outpatients presented for testing due to suspected acute respiratory infection between 1 January and 31 December 2024 to the Teaching Institute for Public Health of Split-Dalmatia County, Croatia, and multiplex real-time PCRs for 13 respiratory pathogens were included. Results: Out of 15,437 analyzed panels, 8878 (57.5%) were positive. Single-pathogen infections dominated (82.6%), while co-infections were recorded in 17.4% of panels; therefore, a total of 10,546 individual pathogens were detected, which were mostly viruses (87.0%). The following distribution of pathogens was observed: rhinovirus/enterovirus in 38.9% of positive results, influenza A virus in 14.5%, SARS-CoV-2 in 9.5%, parainfluenza virus in 7.9%, respiratory syncytial virus in 7.3%, Mycoplasma pneumoniae in 4.9%, Bordetella pertussis in 4.6%, human metapneumovirus in 4.2%, adenovirus in 3.4%, Chlamydia pneumoniae in 3.4%, influenza B virus in 1.3%, Bordetella parapertussis in 0.1% and Legionella pneumophila had one positive result. The first trimester of the year had the highest number of positive test panels (47.0%). Conclusions: Our study demonstrates a predominance of viral pathogens across all age groups and seasons, further supporting guideline-based practice and highlighting the importance of confirming bacterial infection before initiating antibiotic therapy. This insight into the post-pandemic circulation of respiratory pathogens may help inform public health strategies, including improved surveillance, anticipation of seasonal outbreaks, and targeted interventions, thereby supporting future pandemic preparedness and mitigation efforts. Full article

Background/Objectives: Seasonal waves of respiratory viruses—including SARS-CoV-2, influenza A virus (IAV), and respiratory syncytial virus (RSV)—continue to pose a global health burden and highlight the need for antiviral agents that are effective, safe, broadly active, affordable, and widely accessible. Current interventions are limited by the need for their early administration, the risk of resistance, their costs, and the restricted availability in large parts of the world. For certain natural products, such as European black elderberry (Sambucus nigra L.) fruit extract (ElderCraft^®; EC) and the seaweed-derived sulfated polymer iota-carrageenan (IC), antiviral activities against respiratory viruses, particularly IAV and SARS-CoV-2, have previously been shown. Here, we assessed the antiviral activity of IC and an anthocyanin-standardized EC extract against SARS-CoV-2, IAV, and RSV, either as monotherapy or in multiple-dose combinations. Methods: MDCKII cells were infected with IAV_PR8, human Calu-3 lung epithelial cells with the SARS-CoV-2 Omicron variant, and HEp-2 cells with RSV (A2 strain). Inhibitors were administered either by pre-incubation of cell-free virions prior to infection or, in separate time-of-addition experiments, during or post-infection. Viral replication was quantified by qRT-PCR or intracellular immunostaining. Cytotoxicity was evaluated using a neutral red uptake assay. Results: Most intriguingly, both EC and IC are able to neutralize virions derived from SARS-CoV-2, IAV, or RSV extracellularly in a dose-dependent manner. Notably, EC and IC alone exhibited strong anti-RSV activity, which was not reported previously. Most importantly, combined treatment with IC and EC caused a pronounced synergistic antiviral effect against the tested viruses, as confirmed by the Bliss independence model, without any detectable impact on cell viability. Finally, solutions prepared from matrix-standardized mono- or combi-lozenges, containing IC and/or EC in high or low doses, reproduced the antiviral and synergistic combination effects observed with the pure compounds. Conclusions: In summary, these findings support further development of EC and IC as a topically accessible, virion-neutralizing combination (e.g., lozenges) to provide additional protection against major respiratory viruses and potentially strengthen pandemic preparedness. Full article

Zoonotic diseases involve pathogen transmission between humans and animals, with most research focused on animal-to-human spillover. However, reverse zoonosis—the transmission of pathogens from humans to animals—remains understudied despite its potential ecological and epidemiological consequences. The SARS-CoV-2 pandemic highlights this risk, as human-associated viruses may sporadically infect wildlife species and generate novel exposure pathways. To assess evidence of SARS-CoV-2 exposure in wildlife, we analyzed serum and rectal swab samples from rodents collected in rural localities of the Yucatan Peninsula, Mexico, between 2021 and 2022. An indirect ELISA detected antibodies against SARS-CoV-2 in 23.1% of sampled rodents. Molecular analysis detected one positive sample with a pan-coronavirus RT-PCR, though all were negative for SARS-CoV-2–specific assays. This study provides serological evidence of SARS-CoV-2 exposure in rodent communities from rural areas of Mexico and is consistent with sporadic wildlife spillback events rather than sustained transmission. The observed exposure patterns may be influenced by human activities and frequent human–wildlife interactions in heterogeneous rural landscapes. Our results underscore the need for integrated serological and genomic surveillance to better understand the ecological context of reverse zoonosis and its implications for public health. Full article

The mitogen-activated protein kinase (MAPK) pathways, ERK, JNK, and p38, are key regulators of immune responses during viral infections. These signaling cascades control cytokine production, T cell activity, and antigen presentation. However, many viruses can hijack MAPK pathways to avoid immune detection, promote their replication, and establish chronic infection. In this review, we discuss how different viruses, including HSV-1, HBV, HCMV, and SARS-CoV-2, manipulate MAPK signaling to alter host cell functions. A particular focus is given to the CD1d–iNKT cell axis, which plays a critical role in early antiviral responses but is often disrupted through MAPK-dependent mechanisms. We explore how changes in MAPK signaling affect antigen-presenting cells, drive T cell exhaustion, and reprogram immune cell metabolism, factors that contribute to viral immune evasion. The review also examines therapeutic strategies aimed at targeting MAPKs to improve antiviral immunity. These include small-molecule inhibitors and immune modulators that may enhance antiviral responses while limiting side effects. We emphasize the importance of context, as MAPK-targeted therapies must be carefully timed and tailored to avoid suppressing protective immunity or triggering unwanted inflammation. Overall, this review highlights the therapeutic potential and challenges of targeting MAPK pathways in viral infections and encourages further research into selective, host-directed antiviral strategies. Full article

Cellular processes rely heavily on protein phosphorylation, a mechanism essential for organismal physiology and pathology. The CMGC family comprises a large group of serine/threonine kinases defined by a conserved catalytic core and closely related kinase domains. While several CMGC members have been extensively studied, others, including the RCK and CDKL subfamilies, remain less studied. Here, we synthesize current knowledge of CMGC kinases, emphasizing their structural organization, mechanisms of activation, and roles in infection and disease. CMGC kinases such as CDKs and DYRKs are activated downstream of growth factor signaling to drive proliferative programs. In contrast, other CMGC members respond to cellular stress signals, including stress cytokines, and function during quiescence or adverse conditions to regulate antiproliferative and pro-survival pathways. Through these context-dependent activities, CMGCs govern fundamental cellular processes, including growth, metabolism, transcription, and genome integrity. Although individual CMGC kinases operate within distinct signaling cascades, substantial crosstalk exists among their pathways. Both DNA and RNA viruses exploit host CMGC networks to reprogram the intracellular environment and enhance replication. While CMGC–virus interactions are often proviral, specific CMGC-mediated antiviral responses have been described, notably in SARS-CoV-2 infection. Collectively, CMGC kinases occupy a central position in cellular homeostasis and disease. Full article

Human respiratory syncytial virus (RSV) is the predominant etiological agent responsible for lower respiratory tract infections in young children. Recurrent infections throughout an individual’s lifespan can lead to significant morbidity, particularly in the elderly and in adults, influencing the trends of hospitalization rates. Consequently, it is imperative to develop technologies that can sanitize environments from this pathogen while being compatible with human presence. Structure Resonant Energy Transfer (SRET) is the scientific principle underlying a sanitization technology that has demonstrated efficacy against several enveloped viruses, including SARS-CoV-2 and Influenza A viruses. SRET employs specific frequencies of electromagnetic waves to effectively disrupt the structural integrity of viral envelopes through dipole coupling. This disruption leads to the inactivation of the virus, rendering it non-infectious. The objective of this study is to analyse the effect of a specific SRET sanitization method on RSV. The sanitization test was conducted in aerosol form within a BSL-3 laboratory, exploring the frequency band from 8 to 16 GHz. An optimal sub-band was identified, giving an inactivation efficiency up to 99.5%. In conclusion, it has been demonstrated that the microwave non-thermal sanitization method is effective against RSV. These results confirm its potential as a viable approach for environmental decontamination. Full article

Neutrophils are among the early responders of the innate immune system and play a key role in host defense against viral infections. Beyond their classical antimicrobial functions, neutrophils can engage in a specialized defense mechanism by releasing web-like extracellular DNA known as neutrophil extracellular traps (NETs). These extracellular traps are a mesh-like network of chromatin DNA decorated with cellular components, including histones, proteases, and antimicrobial enzymes, that function to contain and limit the spread of pathogens. While NET formation contributes to antiviral immunity, accumulating evidence indicates that excessive or dysregulated NET formation can significantly contribute to immunopathology during viral infections. Thus, depending on the context and outcome, NET formation may be viewed as a double-edged sword. Therefore, understanding the regulatory mechanisms governing NET formation and its harmful effects is critical for developing therapeutic strategies that enhance antiviral defense while minimizing tissue damage. In this review, we provide a comprehensive overview of the molecular mechanisms that drive NET formation and clearance, with a particular focus on how viruses modulate these processes to influence disease outcome. We also discuss the pathways underlying NET formation and subsequent neutrophil cell death (NETosis), including canonical and non-canonical pathways, and highlight key signaling axes involving SYK, MAPKs, and NF-κB. Using SARS-CoV-2 and hepatitis B virus as representative models, we examine how different viral components trigger, exploit, or evade NET targeting and how persistent accumulation of NETs can contribute to hyperinflammation, progressive tissue injury, and post-viral syndromes. We further explore emerging evidence linking impaired NET clearance and neutrophil heterogeneity, particularly low-density neutrophils (LDNs), to chronic inflammation and post-viral sequelae such as long COVID and autoimmune hepatitis. Finally, we summarize current and emerging therapeutic strategies aimed at modulating NET formation or enhancing NET clearance. Altogether, this review underscores the dual nature of NETs in viral infections, highlighting their potential roles in antiviral defense and tissue injury, and provides a framework for the development of targeted interventions to limit virus-induced immunopathology. Full article

Background/Objectives: Influenza, RSV, and SARS-CoV-2 co-circulate and evolve under immune and therapeutic pressures, complicating decision-making for both vaccine formulation and antiviral use. Fragmented, pathogen-specific sequencing approaches limit cross-virus comparability. Methods: We applied a standardized, multiplexed, amplicon-based next-generation sequencing (NGS) workflow to 34 diagnostic specimens (Ct < 35) positive for influenza A/B, RSV-A/B, or SARS-CoV-2. Sequencing libraries were generated and run on an Illumina MiSeq platform (2 × 250 bp). Although the wet-lab workflow is standardized across pathogens, consensus generation and annotation utilized two different analysis environments: Geneious Prime for influenza and MicrobioChek for RSV and SARS-CoV-2. Quality metrics included genome breadth and depth of coverage. Results: Near-complete genomes (mean coverage ≥98%) were recovered for all samples. Influenza A(H1N1)pdm09 sequences clustered in clade 6B.1A; A(H3N2) clustered in subclade 3C.2a1b.2a.2; and influenza B belonged to the Victoria lineage V1A.3a.2. RSV sequences were assigned to Nextclade clades A.D.5.1, A.D.1.10, A.D.2.1, and A.D.3 (RSV-A) and to B.D.4.1.3 and B.D.E.1 (RSV-B), consistent with the ON1 (RSV-A) and BA (RSV-B) genotypes prevalent in recent seasons. Clinically relevant mutations included changes in the influenza HA site and neuraminidase substitutions, RSV F-protein polymorphisms, and spike protein substitutions associated with recent Omicron sublineages (L455F/S, F456L) in SARS-CoV-2. Conclusions: A unified amplicon–NGS approach yields harmonized genomic data across respiratory viruses, enabling timely detection of antigenic drift and resistance markers while supporting integrated, cross-pathogen surveillance. Full article

Background/Objectives: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza virus are dangerous respiratory pathogens with high pandemic potential. Since 2021, these two viruses have been co-circulating, which implies additional risks of co-infection with both pathogens. Prophylactic vaccination is widely recognized as the most effective way to prevent COVID-19 and influenza and to reduce the severity of these diseases. This review analyzes recent data on the simultaneous circulation of influenza and SARS-CoV-2 viruses worldwide, including epidemiological data and the pathogenetic mechanisms of co-infection. Next, we focus on current approaches to simultaneous and combined vaccination against influenza and COVID-19. We outline the types of vaccines and summarize the available findings on the effectiveness and safety of co-vaccination. Methods: A comprehensive search was conducted using PubMed, Scopus, Web of Science, and ClinicalTrials to identify data relevant to SARS-CoV-2 and influenza co-circulation and dual vaccination. Results: Influenza and SARS-CoV-2 cause similar symptoms, and co-infection can significantly enhance the risks of pneumonia and acute respiratory distress syndrome progressing with a poor outcome, especially among children and the elderly. A range of influenza and COVID-19 vaccines built on different technological platforms is currently available on the market, with proven effectiveness, immunogenicity, and safety. A co-vaccination approach is more convenient for patients and is associated with better response to treatment, while also improving vaccine coverage and compliance and offering significant resource savings for healthcare systems. Conclusions: The concurrent circulation of SARS-CoV-2 and influenza viruses presents a growing public health challenge. Simultaneous and combination vaccination strategies have emerged as effective tools to streamline immunization, enhance protection, and reduce healthcare burden. Future studies should elucidate the mechanisms of the exacerbation of respiratory disease caused by co-infection, as well as the optimal strategies for co-administering influenza and COVID-19 vaccines for long-term control of seasonal and potentially pandemic respiratory viruses. Full article

Background/Objectives: Nosocomial outbreaks of viral respiratory infections strain healthcare systems and endanger patients and healthcare workers (HCWs). We describe two large nosocomial outbreaks with the SARS-CoV-2 Alpha variant, during its initial emergence in Germany, to assess transmission dynamics, effectiveness of control measures, and challenges in managing highly transmissible respiratory viruses. Methods: Confirmed cases were inpatients, HCWs, or their contacts testing SARS-CoV-2-positive since 1 January 2021 (Hospital A [HA])) or 21 January 2021 (Hospital B [HB])) with N501Y and delH69/V70 spike gene mutations. We conducted case interviews, reviewed medical records and shift schedules, and performed sequencing, genome reconstruction, and phylogenetic analysis. We describe cases, transmission chains, and control measures. Results: HA reported 18 patient cases, 20 HCW cases, and 33 community cases (N = 71). HB reported 48 patient cases, 43 HCW cases (13 in a COVID-19 ward), and 27 community cases (N = 118). In-hospital transmission occurred patient-to-patient, HCW-to-patient, patient-to-HCW, and HCW-to-HCW. HA halted admissions immediately after the initial cases; HB implemented measures gradually. Regular testing detected pre-symptomatic (HA = 6; HB = 18) and asymptomatic cases (HA = 3; HB = 13). Testing of agency staff was incomplete. The suspected primary case was an HCW in HA and a patient in HB who required resuscitation shortly after admission. Conclusions: Early COVID-19 outbreaks offer valuable lessons for managing emerging nosocomial outbreaks of highly transmissible respiratory viruses. Our findings provide empirical evidence for effective interventions, including rapid response, testing, HCW protection, and rigorous contact tracing in high-risk emergency situations. Managing agency staff remains a major challenge. Full article

Clinical, experimental, and computational evidence of COVID-19 virulence and infectivity has been linked to SARS-CoV-2 shell disorder. A strong link was first discovered using an AI disorder-predicting tool, which detected an unusually hard (low disorder) outer shell among all SARS-CoV-2-related viruses but not in the 2003 SARS-CoV-1. This could account for the high infectivity found in SARS-CoV-2—but not in SARS-CoV-1—as it is believed that hard shells protect viral particles from the onslaught of the antimicrobial enzymes present in the respiratory system and saliva. As a result, much larger quantities of particles are shed by COVID-19 patients. Abnormally hard outer shells (M) are associated with burrowing animals, e.g., pangolins, and SARS-CoV-2 likely acquired these shells due to its long-term evolutionary interactions with pangolins. As for virulence, the inner shell of SARS-CoV-2 (N) has been found to exhibit lower disorder than that of SARS-CoV-1. This lower disorder is consistent with the fact that SARS-CoV-2 is less virulent than SARS-CoV-1, as higher disorder in the inner shell is associated with more efficient protein–protein binding during replication. The link between N/M disorder and virulence or infectivity falls under the umbrella of shell disorder models (SDMs), which can connect virulence, infectivity, and long COVID under one coherent concept. Evidence of the reliability and reproducibility of SDMs as applied to COVID-19 is examined. The hard M that is resisting the antimicrobial enzymes in the respiratory system can be extended to immunological enzymes, especially those found in phagocytes such as macrophages, which can therefore become a reservoir for the virus. Full article