Search Results (1,134)

In this paper we aimed to compare seasonality, clinical characteristics, and outcomes of Influenza A and COVID-19 in the context of influenza reemergence and ongoing Omicron circulation. We performed a retrospective comparative analysis at the Teaching Hospital of Infectious Diseases in Cluj-Napoca, Romania. We included adult patients hospitalized with Influenza A or COVID-19 between 1 November 2022 and 31 March 2024. Data were collected on demographics, clinical presentation, complications, and in-hospital mortality. We included 899 COVID-19 and 423 Influenza A patients. The median age was 74 years for COVID-19 and 65 for Influenza A (p < 0.001). The age-adjusted Charlson comorbidity index was higher in COVID-19 patients (5 vs. 3, p < 0.001). Despite this age gap, acute respiratory failure was more common in Influenza A (62.8% vs. 55.7%, p = 0.014), but ventilation rates did not differ significantly. Multivariate models showed Influenza A was associated with increased risk of intensive-care unit (ICU) admission or ventilation, whereas older COVID-19 patients had higher in-hospital mortality (5.67% vs. 3.3%, p = 0.064). Omicron COVID-19 disproportionately affected older patients with comorbidities, contributing to higher in-hospital mortality. However, Influenza A remained a significant driver of respiratory failure and ICU admission, underscoring the importance of preventive measures in high-risk groups. Full article

Highly pathogenic avian influenza (HPAI) remains a persistent threat to global poultry production and public health. Current vaccine platforms show limited cross-clade efficacy and often fail to induce mucosal immunity. Recent advances in microbiome research reveal critical roles for gut commensals in modulating vaccine-induced immunity, including enhancement of mucosal IgA production, CD8⁺ T-cell activation, and modulation of systemic immune responses. Engineered commensal bacteria such as Lactococcus lactis, Bacteroides ovatus, Bacillus subtilis, and Staphylococcus epidermidis have emerged as promising live vectors for antigen delivery. Postbiotic and synbiotic strategies further enhance protective efficacy through targeted modulation of the gut microbiota. Additionally, artificial intelligence (AI)-driven tools enable predictive modeling of host–microbiome interactions, antigen design optimization, and early detection of viral antigenic drift. These integrative technologies offer a new framework for mucosal, broadly protective, and field-deployable vaccines for HPAI control. However, species-specific microbiome variation, ecological safety concerns, and scalable manufacturing remain critical challenges. This review synthesizes emerging evidence on microbiome–immune crosstalk, commensal vector platforms, and AI-enhanced vaccine development, emphasizing the urgent need for One Health integration to mitigate zoonotic adaptation and pandemic emergence. Full article

Background/Objectives: An influenza pandemic is likely to occur in the coming decades and will be associated with substantial healthcare and financial burdens. In this study, we evaluated the potential economic costs of different vaccination scenarios for the US population in the context of a moderate or severe influenza pandemic. Methods: Economic analysis was performed for initiation of pandemic vaccination from 3 months vs. 6 months in the US after declaration of a pandemic. We evaluated three vaccine effectiveness levels (high, moderate, low) and two pandemic severity levels (moderate and severe). Results: No vaccination would lead to total direct and indirect costs of $116 bn in a moderate pandemic and $823 bn in a severe pandemic. Initiation of vaccination at 3 months would result in cost savings versus no vaccination (excluding vaccine price) of $30–84 bn and $260–709 bn in a moderate and severe pandemic, respectively, whereas initiation of vaccination at 6 months would result in cost savings of $4–11 bn and $36–97 bn, respectively. Cost savings of $20 bn and $162 bn would occur in a moderate or severe pandemic, respectively, from use of a low effectiveness vaccine from 3 months instead of a high effectiveness vaccine from 6 months. Conclusions: Rapid initiation of vaccination would have a greater impact than increased vaccine effectiveness in reducing the economic impacts of an influenza pandemic. Full article

Background/Objectives: The SARS-CoV-2 and influenza A (H1N1)pdm09 pandemics have resulted in high numbers of ICU admissions, with high mortality. Identifying risk factors for ICU mortality at the time of admission can help optimize clinical decision making. However, the risk factors identified may differ, depending on the type of analysis used. Our aim is to compare the risk factors and performance of a linear model (multivariable logistic regression, GLM) with a non-linear model (random forest, RF) in a large national cohort. Methods: A retrospective analysis was performed on a multicenter database including 8902 critically ill patients with influenza A (H1N1)pdm09 or COVID-19 admitted to 184 Spanish ICUs. Demographic, clinical, laboratory, and microbiological data from the first 24 h were used. Prediction models were built using GLM and RF. The performance of the GLM was evaluated by area under the ROC curve (AUC), precision, sensitivity, and specificity, while the RF by out-of-bag (OOB) error and accuracy. In addition, in the RF, the im-portance of the variables in terms of accuracy reduction (AR) and Gini index reduction (GI) was determined. Results: Overall mortality in the ICU was 25.8%. Model performance was similar, with AUC = 76% for GLM, and AUC = 75.6% for RF. GLM identified 17 independent risk factors, while RF identified 19 for AR and 23 for GI. Thirteen variables were found to be important in both models. Laboratory variables such as procalcitonin, white blood cells, lactate, or D-dimer levels were not significant in GLM but were significant in RF. On the contrary, acute kidney injury and the presence of Acinetobacter spp. were important variables in the GLM but not in the RF. Conclusions: Although the performance of linear and non-linear models was similar, different risk factors were determined, depending on the model used. This alerts clinicians to the limitations and usefulness of studies limited to a single type of model. Full article

Background: Influenza A viruses (IAV) cause seasonal flu and occasional pandemics. In addition, the potential for the emergence of new strains presents unknown challenges for public health. Face masks and other personal protective equipment (PPE) can act as barriers that prevent the spread of these viruses. Metal ions embedded into PPE have been demonstrated to inactivate respiratory viruses, but the underlying mechanism of inactivation and potential for resistance is presently not well understood. Methods: In this study, we used hemagglutination assays to quantify the effect of zinc ions on IAV sialic acid receptor binding. We varied the zinc concentration, incubation time, incubation temperature, and passaged IAV in the presence of zinc ions to investigate if resistance to zinc ions could evolve. Results: We found that zinc ions impact the ability of IAV particles to hemagglutinate and observed inhibition within 1 min of exposure. Maximum inhibition was achieved within 1 h and sustained for at least 24 h in a concentration-dependent manner. Inhibition was also temperature-dependent, and optimal above room temperature. Serial passaging of IAV in the presence of zinc ions did not result in resistance. Conclusions: e conclude that zinc ions prevent IAV hemagglutination in a concentration and temperature-dependent manner for at least 24 h. Overall, these findings are in line with previous observations indicating that zinc-embedded materials can inactivate the IAV hemagglutinin and SARS-CoV-2 spike proteins, and they support work toward developing robust, passive, self-cleaning antiviral barriers in PPE. Full article

The uptake of the COVID-19 and seasonal influenza (SI) vaccines have decreased in Europe and especially in Malta. The present study aimed to investigate the attitudes toward COVID-19 and SI vaccines and determine if individuals perceive that these vaccines are relevant to protect their health and identify reasons for their responses. A cross-sectional study using an anonymous questionnaire, informed by the Theory of Planned Behavior, addressing behavior beliefs and attitudes, and targeted at adult residents in Malta, was designed on Google Forms and disseminated using social media between January and March 2024. A total of 555 responses were received. The majority of respondents did not take/intend to take the COVID-19 (75%, n = 417) or SI (64.3%, n = 362) vaccines, with females being less likely to do so (p = 0.033). Perceived lack of safety (31.3%, n = 174) was the primary reason for rejecting the COVID-19 vaccine, and perceived lack of a threat from SI (26%, n = 144) was the reason for rejecting the SI vaccine. Those having chronic conditions were positively associated with uptake of both vaccines. In the post-pandemic era, these vaccines are not envisaged as having a major role in protecting one’s health. A high degree of skepticism especially toward the combined COVID-19 and SI vaccine in terms of safety, mostly in women, is still present. Full article

Coronavirus disease (COVID-19) is an infectious disease caused by the SARS-CoV-2 virus, whose 2020 outbreak was characterized as a pandemic by the World Health Organization. Restriction measures changed healthcare delivery, with telehealth providing a viable alternative throughout the pandemic. This study analyzed a telemedicine platform database with the goal of developing a diagnostic prediction model for COVID-19 patients. This is a longitudinal study of patients seen on the Conexa Saúde telemedicine platform in 2022. A multiple binary logistic regression model of controls (negative confirmation for COVID-19 or confirmation of other influenza-like illness) versus COVID-19 was developed to obtain an odds ratio (OR) and a 95% confidence interval (CI). In the final binary logistic regression model, six factors were considered significant: presence of rhinorrhea, ocular symptoms, abdominal pain, rhinosinusopathy, and wheezing/asthma and bronchospasm were more frequent in controls, thus indicating a greater chance of flu-like illnesses than COVID-19. The presence of tiredness and fatigue was three times more prevalent in COVID-19 cases (OR = 3.631; CI = 1.138–11.581; p-value = 0.029). Our findings suggest potential predictors associated with influenza-like illness and COVID-19 that may distinguish between these infections. Full article

Avian influenza viruses (AIVs) pose significant risks to occupational populations engaged in poultry farming, livestock handling, and live poultry market operations due to frequent exposure to infected animals and contaminated environments. This review synthesizes evidence on AIV exposure patterns and risk factors through a comprehensive analysis of viral characteristics, host dynamics, environmental influences, and human behaviors. The main routes of transmission include direct animal contact, respiratory contact during slaughter/milking, and environmental contamination (aerosols, raw milk, shared equipment). Risks increase as the virus adapts between species, survives longer in cold/wet conditions, and spreads through wild bird migration (long-distance transmission) and live bird trade (local transmission). Recommended control measures include integrated animal–human–environment surveillance, stringent biosecurity measures, vaccination, and education. These findings underscore the urgent need for global ‘One Health’ collaboration to assess risk and implement preventive measures against potentially pandemic strains of influenza A viruses, especially in light of undetected mild/asymptomatic cases and incomplete knowledge of viral evolution. Full article

Background: Zoonotic influenza viruses pose a significant and evolving public health threat. In response to the recent rise in H5N1 cross-species transmission, the World Health Organization (WHO) R&D Blueprint for Epidemics consultations have prioritized strengthening surveillance, candidate vaccines, diagnostics, and pandemic preparedness. Serological surveillance plays a pivotal role by providing insights into the prevalence and transmission dynamics of influenza viruses. Objective: This scoping review aimed to map the global research landscape on serological surveillance of zoonotic influenza in animals and exposed humans between 2017, the date of the last WHO public health research agenda for influenza review, and 2024, as well as to identify methodological advancements. Methods: Following PRISMA-ScR guidelines, we searched PubMed for English-language peer-reviewed articles published between January 2017 and March 2024. Studies were included if they reported serological surveillance in wild or domestic animals or occupationally exposed human populations, or novel methodologies and their technical limitations and implementation challenges. Results: Out of 7490 screened records, 90 studies from 33 countries, covering 25 animal species, were included. Seroprevalence studies were in domestic poultry and swine. Surveillance in companion animals, wild mammals, and at the human–animal interface was limited. Emerging serological methods included multiplex and nanobody-based assays, though implementation barriers remain. Conclusions: The review is limited by its restriction to one database and English-language articles, lack of quality appraisal, and significant heterogeneity among the included studies. Serological surveillance is a critical but underutilized tool in zoonotic influenza monitoring. Greater integration of serological surveillance into One Health frameworks, especially in high-risk regions and populations, is needed to support early detection and pandemic preparedness. Full article

Respiratory pathogens are significant causes of morbidity and mortality worldwide. Since the emergence of SARS-CoV-2 in 2019 and the mitigation measures implemented to control the pandemic, other respiratory viruses’ transmission and circulation patterns were substantially disrupted. We leveraged the influenza hospitalization surveillance in Tanzania to understand the distribution of respiratory viruses shortly after nonpharmaceutical interventions (NPIs) were lifted. A total of 475 samples that tested negative for SARS-CoV-2 and influenza from March through May 2022 were included in this study. The samples were tested for 16 virus targets using Anyplex II RV16 multiplex assays. The findings indicate that most hospitalizations (74%) were among children under 15 years, with human bocavirus (HBoV) being the most prevalent (26.8%), followed by rhinovirus (RV, 12.3%), parainfluenza viruses (PIVs1–4, 10.2%), respiratory syncytial virus (RSV, 8.7%), adenovirus (AdV, 4.3%), and metapneumovirus (MPV, 2.9%). Notably, 54% of respiratory hospitalizations had no viruses detected. The findings highlight the broad circulation of respiratory viruses shortly after NPIs were lifted in Tanzania. Surveillance for respiratory pathogens beyond influenza and SARS-CoV-2 can inform public health officials of emerging threats in the country and should be considered an important pandemic preparedness measure at a global level. Full article

The COVID-19 pandemic significantly impacted the circulation, seasonality, and disease burden of viral respiratory infections. This study aimed to evaluate the impact of SARS-CoV-2 on the frequency of viral respiratory infections at a teaching hospital in Southern Italy by comparing data from before, during, and after the COVID-19 pandemic and by investigating how the emergence of SARS-CoV-2 affected the circulation and seasonality of other respiratory viruses. This retrospective and prospective study was performed on de-identified nasopharyngeal specimens classified as pre-COVID-19 (before 15 March 2020), during-COVID-19 (from 16 March 2020 to 5 May 2023), and post-COVID-19 (from 6 May 2023 to 31 December 2024). Overall, 790 out of 3930 (20%) patient samples tested positive for at least one respiratory virus. The mean age of patients was 60 ± 19 years, with significant positivity rates observed in the 65–98 age group (p ≤ 0.05) across all periods. In the pre-COVID-19 period, the most prevalent virus was influenza A (47.5%, 47/99), followed by the human rhinovirus (19.2%, 19/99). During the COVID-19 pandemic, SARS-CoV-2 was the most prevalent (64.9%, 290/447), before decreasing to 38% (92/244) after the pandemic, while influenza A’s positivity prevalence increased to 14.3% (35/244). Rhinovirus/enterovirus remained relatively stable throughout all periods. The pandemic notably altered viral co-infection dynamics, with its effects lasting into the post-COVID-19 period. Specifically, a marked decrease in influenza A circulation was observed, while respiratory syncytial virus (RSV) epidemiology remained stable and significant co-circulation of rhinovirus/enterovirus with SARS-CoV-2 persisted. Therefore, since COVID-19 and influenza affect the same high-risk groups, those individuals must be vaccinated against both viruses. Full article

Bacterial meningitis remains a critical public health issue globally due to its high morbidity and mortality. Understanding regional epidemiological trends is essential to inform vaccination strategies and public health interventions. This observational, retrospective study analyzed cerebrospinal fluid (CSF) isolates collected from 731 confirmed cases of bacterial meningitis between 2014 and 2024 in Lombardy, Italy. Pathogen identification and serotyping of Streptococcus pneumoniae (SP), Neisseria meningitidis (NM), and Haemophilus influenzae (HI) were conducted using culture-based and molecular techniques. Trends were assessed across age groups and time using Kruskal–Wallis and chi-square tests. Results: SP was the predominant pathogen (78.4%), followed by NM (13.0%) and HI (8.6%). Significant temporal variation was observed for SP and NM, while HI trends remained stable. The impact of COVID-19-related restrictions was evident in a reduction in cases during 2020–2021. SP serotypes 3 and 8, HI non-typeable strains, and NM serogroup B were most frequent. No major shifts in serotype distribution were observed. Long-term surveillance data from Lombardy underscore the dominance of vaccine-targeted serotypes, ongoing circulation of resilient clones, and post-pandemic epidemiological shifts. These findings support continuous surveillance and inform vaccine strategy adjustments at the regional and national levels. Full article

Arboviruses are a growing concern in many nations. Several reports of arboviral outbreaks have been recorded globally in the past decade alone. Repeated arboviral outbreaks in developing countries have consistently highlighted vulnerabilities in disease surveillance and response systems, exposing critical gaps in early detection, contact tracing, and resource allocation. The 2024 Dengue fever outbreak in Ghana, which recorded 205 confirmed cases out of 1410 suspected cases, underscored the urgent need to evaluate the country’s preparedness for arboviral outbreaks, given the detection of competent vectors in the country. A retrospective analysis of Ghana’s 2009–2013 pandemic influenza response plan revealed significant deficiencies in emergency preparedness, raising concerns about the country’s ability to manage emerging arboviral threats. This review assessed Ghana’s current arboviral outbreak response and preparedness by examining (a) the effectiveness of vector control measures, (b) the role of early warning systems in mitigating outbreaks, (c) laboratory support and diagnostic capabilities, and (d) community engagement strategies. It highlights the successes made in previous outbreaks and sheds light on several gaps in Ghana’s outbreak response efforts. This review also provides recommendations that can be implemented in many countries across Africa as they brace themselves for any arboviral outbreak. Full article

Background: Influenza is a significant global respiratory infection, and vaccinating reproductive-age women, particularly in densely populated countries like China, cannot be overlooked. In this study, we aimed to determine influenza vaccination coverage, vaccine hesitancy, as well as associated factors among Chinese women aged 18–49 years old. Methods: A cross-sectional survey among women aged 18–49 years was conducted in China from 15 to 30 March 2023. We collected information such as past-year influenza vaccination, demographic characteristics, health-related factors, COVID-19-related factors, and perceived susceptibility and severity of influenza. Influenza vaccine acceptance among participants who did not receive influenza vaccination in the past year was also investigated. Multivariable logistic regression analyses were employed to investigate the influencing factors of vaccine coverage and vaccine hesitancy. Results: A total of 1742 reproductive-aged women were included in the final analysis. The past-year influenza vaccine coverage among women aged 18–49 years old was only 39.32% in China. Age ≥ 35 years (aOR = 0.72, 95% CI: 0.56–0.94), renting accommodation (aOR = 0.57, 95% CI: 0.44–0.75), and history of COVID-19 infection (aOR = 0.65, 95% CI: 0.47–0.89) and COVID-19 vaccine hesitancy (aOR = 0.39, 95% CI: 0.29–0.54) were all identified as negative correlates of influenza vaccine coverage among Chinese reproductive-aged women, while participants with a history of chronic diseases (aOR = 1.57, 95% CI: 1.23–2.01) and noticeable pandemic fatigue due to COVID-19 (aOR = 1.45, 95% CI: 1.05–2.00) were prone to have higher vaccination rates. Among reproductive-aged women who did not receive influenza vaccination in the past year, the hesitancy rate regarding future influenza vaccination was 31.79%. Factors such as older age, urban residence, living with others, poor self-rated health status, absence of chronic diseases, completion of full COVID-19 vaccination, COVID-19 vaccine hesitancy, pandemic fatigue, and failure to perceive the susceptibility and severity of influenza might increase influenza vaccine hesitancy. Discussion: Overall, a lower coverage rate of influenza vaccine was notably observed among Chinese reproductive-age women, as well as the hesitancy regarding future vaccination. To effectively mitigate the impact of influenza and reduce the incidence of associated diseases, it is imperative to devise targeted intervention strategies and policies tailored to reproductive-age women. Full article

Since 2020, the Gs/Gd H5N1 influenza virus (clade 2.3.4.4b) has established itself within wild bird populations across Asia, Europe, and the Americas, causing outbreaks in wild mammals, commercial poultry, and dairy farms. The impacts on the bird populations and the agricultural industry has been significant, requiring a One Health approach to enhanced surveillance in both humans and animals. To support pandemic preparedness efforts, we evaluated the Cepheid Xpert Xpress CoV-2/Flu/RSV plus kit and the BioFire Respiratory 2.1 Panel for their ability to detect the presence of non-seasonal, zoonotic influenza A viruses, including circulating H5N1 viruses from clade 2.3.4.4b. Both assays effectively detected the presence of influenza virus in clinically-contrived nasal swab and saliva specimens at low concentrations. The results generated using the Cepheid Xpert Xpress CoV-2/Flu/RSV plus kit and the BioFire Respiratory 2.1 Panel, in conjunction with clinical and epidemiological findings provide valuable diagnostic findings that can strengthen pandemic preparedness and surveillance initiatives. Full article