Socioeconomic impact of seasonal (epidemic) influenza and the role of over-the-counter medicines

Nucleotide and dinucleotide preference of segmented viruses are shaped more by segment: In case study of tomato spotted wilt virus

Several studies have showed that the nucleotide and dinucleotide composition of viruses possibly follows their host species or protein coding region. Nevertheless, the influence of viral segment on viral nucleotide and dinucleotide composition is still unknown. Here, we explored through tomato spotted wilt virus (TSWV), a segmented virus that seriously threatens the production of tomatoes all over the world. Through nucleotide composition analysis, we found the same over-representation of A across all viral segments at the first and second codon position, but it exhibited distinct in segments at the third codon position. Interestingly, the protein coding regions which encoded by the same or different segments exhibit obvious distinct nucleotide preference. Then, we found that the dinucleotides UpG and CpU were overrepresented and the dinucleotides UpA, CpG and GpU were underrepresented, not only in the complete genomic sequences, but also in different segments, protein coding regions and host species. Notably, 100% of the data investigated here were predicted to the correct viral segment and protein coding region, despite the fact that only 67% of the data analyzed here were predicted to the correct viral host species. In conclusion, in case study of TSWV, nucleotide composition and dinucleotide preference of segment viruses are more strongly dependent on segment and protein coding region than on host species. This research provides a novel perspective on the molecular evolutionary mechanisms of TSWV and provides reference for future research on genetic diversity of segmented viruses.

Factors associated to the presence of headache in patients with influenza infection and its consequences: a 2010-2020 surveillance-based study

Headache is a common symptom of influenza infection; however, its causes and consequences remain uncertain. In this manuscript, we analyzed which demographic and clinical factors were associated with the presence of headache during the course of influenza infection and whether patients with headache had a different prognosis, evaluated by need of hospitalization, sick leave or school absenteeism. The influence study (NCT05704335) was an observational study that analyzed data routinely collected from the Health Sentinel Network between 2010 and 2020. During the study period, 7832 cases were considered, among which, 5275 (67.4%) reported headache. The presence of headache was independently associated with myalgia (2.753; 95%CI: 2.456-3.087, P < 0.001), asthenia (OR: 1.958; 95%CI: 1.732-2.214, P < 0.001), shivering (OR: 1.925; 95%CI: 1.718-2.156, P < 0.001), nasopharyngeal erythema (OR: 1.505; 95%CI: 1.293-1.753, P < 0.001), fever (OR: 1.469; 95%CI: 1.159-1.861; P = 0.001), sudden onset of symptoms (OR: 1.380; 95%CI: 1.120-1.702, p = 0.004), female sex (OR: 1.134; 95%CI: 1.023-1.257, P = 0.018), and gastrointestinal symptoms (OR: 1.169; 95%CI: 1.039-1.315; P = 0.01). Patients with headache had a sex and age adjusted lower odds of being referred to the hospital (OR: 0.463; 95%CI: 0.264-0.812, P = 0.007) and a higher odd of having a sick leave and/or school absenteeism (absenteeism (OR: 1.342; 95%CI: 1.190-1.514, P < 0.001). In conclusion, the presence of headache seems associated with symptoms caused by the innate immune response. These findings support a headache pathophysiology linked with the innate immune response. Due to the potential negative consequences and its treatable nature, clinicians should systematically evaluate it and, whenever necessary, treat it too.

Socioeconomic impacts of airborne and droplet-borne infectious diseases on industries: a systematic review

BACKGROUND

Recent pandemics have had far-reaching effects on the world's largest economies and amplified the need to estimate the full extent and range of socioeconomic impacts of infectious diseases outbreaks on multi-sectoral industries. This systematic review aims to evaluate the socioeconomic impacts of airborne and droplet-borne infectious diseases outbreaks on industries.

METHODS

A structured, systematic review was performed according to the PRISMA guidelines. Databases of PubMed, Scopus, Web of Science, IDEAS/REPEC, OSHLINE, HSELINE, and NIOSHTIC-2 were reviewed. Study quality appraisal was performed using the Table of Evidence Levels from Cincinnati Children's Hospital Medical Center, Joanna Briggs Institute tools, Mixed Methods Appraisal Tool, and Center of Evidence Based Management case study critical appraisal checklist. Quantitative analysis was not attempted due to the heterogeneity of included studies. A qualitative synthesis of primary studies examining socioeconomic impact of airborne and droplet-borne infectious diseases outbreaks in any industry was performed and a framework based on empirical findings was conceptualized.

RESULTS

A total of 55 studies conducted from 1984 to 2021 were included, reporting on 46,813,038 participants working in multiple industries across the globe. The quality of articles were good. On the whole, direct socioeconomic impacts of Coronavirus Disease 2019, influenza, influenza A (H1N1), Severe Acute Respiratory Syndrome, tuberculosis and norovirus outbreaks include increased morbidity, mortality, and health costs. This had then led to indirect impacts including social impacts such as employment crises and reduced workforce size as well as economic impacts such as demand shock, supply chain disruptions, increased supply and production cost, service and business disruptions, and financial and Gross Domestic Product loss, attributable to productivity losses from illnesses as well as national policy responses to contain the diseases.

CONCLUSIONS

Evidence suggests that airborne and droplet-borne infectious diseases have inflicted severe socioeconomic costs on regional and global industries. Further research is needed to better understand their long-term socioeconomic impacts to support improved industry preparedness and response capacity for outbreaks. Public and private stakeholders at local, national, and international levels must join forces to ensure informed systems and sector-specific cost-sharing strategies for optimal global health and economic security.

InfluenCEF study: Clinical phenotype and duration of headache attributed to influenza infection

INTRODUCTION

Headache is a frequent symptom of infections. We aimed to characterize the clinical phenotype and duration of headache attributed to influenza infection.

METHODS

Prospective cohort study done in 53 primary care centers between January and April 2023. Patients were included if they had a confirmed influenza diagnosis, were older than 15 years and had a new-onset headache. Patients' demographics, prior medical history, headache phenotype and duration, associated symptoms and patients' outcomes were assessed. The International Classification of Headache Disorders criteria for headache attributed to a systemic viral infection, migraine and tension-type headache were assessed.

RESULTS

Of the 478 patients 75 fulfilled eligibility criteria. The mean age was 43, 56% were men, and 27% had a prior headache history. The headache phenotype was a bilateral headache (52%), with frontal topography (48%), pressing quality (61%), moderate intensity, rhinorrhea (79%), nasal congestion (76%), and photophobia (59%). All patients fulfilled headache attributed to acute systemic viral infection criteria, 43% fulfilled migraine criteria and 31% tension-type headache criteria. The median duration of the headache was four (Inter-quartile range: two-six) days.

CONCLUSION

The clinical phenotype of headache attributed to influenza infection was similar to other infections, with more pronounced cranial autonomic symptoms. The headache was an early symptom and was self-limited within a few days.Trial Registration: The study protocol is registered in ClinicalTrial.gov (NCT05704335).

Impact of pension income on healthcare utilization of older adults in rural China

OBJECTIVE

In China, rural residents experience poorer health conditions and a higher disease burden compared to urban residents but have lower healthcare services utilization. Rather than an insurance focus on enhanced healthcare services utilization, we aim to examine that whether an income shock, in the form of China's New Rural Pension Scheme (NRPS), will affect outpatient, inpatient and discretionary over-the-counter drug utilization by over 60-year-old rural NRPS residents.

METHODS

Providing a monthly pension of around RMB88 (USD12.97), NRPS covered all rural residents over 60 years old. Fuzzy regression discontinuity design (FRDD) was employed to explore the NRPS causal effect on healthcare services utilization, measured by outpatient and inpatient visits and discretionary over-the-counter drug purchases. The nationwide China Health and Retirement Longitudinal Study (CHARLS) 2018 provided the data.

RESULTS

Without significant changes in health status and medication needs, 60-plus-year-old NRPS recipients significantly increased the probability of discretionary OTC drug purchases by 33 percentage points. NRPS had no significant effect on the utilization of outpatient and inpatient utilization. The increase in the probability of discretionary OTC drug purchases from the NRPS income shock was concentrated in healthier and low-income rural residents. Robustness tests confirmed that FRDD was a robust estimation method and our results are robust.

CONCLUSION

NRPS was an exogenous income shock that significantly increased the probability of discretionary over-the-counter drug purchases among over 60-year-old rural residents, but not the utilization of inpatient or outpatient healthcare services. Income remains an important constraint for rural residents to improve their health. We recommend policymakers consider including commonly used over-the-counter drugs in basic health insurance reimbursements for rural residents; provide health advice for rural residents to make discretionary over-the-counter drug purchases; and to mount an information campaign on over-the-counter drug purchasing in order to increase the health awareness of rural residents.

A Detailed Analysis of the Past 20 Years of US FDA-Approved Prescription to Over-the-Counter Switches

OBJECTIVES

This evaluation assesses the quantity, uniqueness, and innovative nature of the past 20 years of Rx-to-OTC (RTO) switches, where a current prescription (Rx) product is reclassified for over-the-counter (OTC) status. Broadening access to more OTC drugs with well-established safety and efficacy could help to reduce healthcare expenditure and address public health challenges.

METHODS

The FDA-maintained RTO switch list website was accessed to generate the primary dataset. Each product listed was assessed for the current OTC availability in the United States of its active ingredient, pharmacological class, and indication to determine its innovative quality. Descriptive statistics were employed in this study.

RESULTS

From January 2002 through August 2022 there were 45 RTO switches. Among these, 51.1% involved a new to OTC active ingredient, 22.2% involved a new pharmacological class, 6.6% involved a new indication, and 82.2% were considered follow-on products that introduced a new to OTC active ingredient or new dosage form of an already marketed active ingredient to treat an existing OTC indication. A small minority (6.6%) were considered an exceptional innovation that would offer US consumers a genuinely novel OTC product, providing a new to OTC active pharmaceutical ingredient, pharmacological class, and indication. Overall, there was 1 exceptional innovation every 6.7 years.

CONCLUSIONS

Over 40 RTO switches have come to the OTC market in the past 20 years; however, exceptional innovations that expand access to new to OTC active ingredients for new indications are rare. Policies and strategies that result in more innovative switches that can benefit consumers and public health should be evaluated.

Glycyrrhizic Acid-Based Carbonized Dots Boost Antiviral Activity against Influenza A Virus via Multisite Inhibition Mechanisms

Influenza A virus (IVA) has been continuously causing pandemics in several animal hosts and has become a worldwide public health threat. Currently, antiviral drugs have become associated with a lot of side effects and limited activity against emerging drug-resistant influenza viruses. Therefore, the development of novel antiviral drugs is of great importance. In this study, we synthesized a kind of carbon dots (CDs) with high dispersibility from glycyrrhizic acid (GA) using a simple dry heating method. Compared with glycyrrhizic acid alone, GA-CDs exhibit superior solubility and significantly improve the antiviral property against IVA. Investigation of the mechanism revealed that GA-CDs act against IVA mainly by inhibiting viral internalization, replication of the viral genome, neuraminidase activity, and host inflammatory responses. More importantly, in a mouse model, GA-CDs can significantly alleviate the clinical symptoms and decrease mortality and lung viral titers. In vitro and in vivo experiments demonstrate that GA-CDs possess extraordinary therapeutic effects; therefore, we propose that GA-CDs may be a promising alternative therapy for IVA infection.

Economic impact of acute respiratory disease pandemics: A scoping review

Background

The economic impact of acute respiratory disease pandemics has yet to be specifically systematically reviewed. The aim of this scoping review is to identify and classify the economic impacts and its values and ranges.

Materials and Methods

We conducted a literature search across three key databases using an extensive list of keywords. Then, we included studies which explored direct and indirect costs as well as broader economic impact associated with different nine acute respiratory diseases, i.e., pandemic and seasonal influenza, avian influenza, equine influenza, swine influenza, severe acute respiratory syndrome, coronavirus disease 2019, Middle East respiratory syndrome, H1N1, and H7N9.

Results

We included 62 studies in English language between 1987 and 2020, mostly from the countries of East Asia and Pacific pertinent. We classified the economic impact into 5 main categories and 18 subcategories. The main categories were macroeconomic impacts, impacts on health cost, industry, businesses and trade, and education.

Conclusion

Respiratory disease pandemics have widely impacted different sectors of economy such as the direct cost on macroeconomic, providing and receiving health services, disease management, industries, business and trade, education, and indirect costs due to productivity losses. However, lots of the reviewed studies were unable to quantify the actual economic cost of these impacts. This made it challenging to conduct any kind of quantitative comparison of the results. A key priority for future research is to develop standard methods to quantify the broader economic costs of respiratory disease pandemics. Understanding the total economic impact of respiratory disease pandemics is a key step to inform national and international priority setting for disease prevention and pandemic control interventions.

Influenza vaccination coverage in pediatric population in Italy: an analysis of recent trends

BACKGROUND

Influenza is a major cause of morbidity, mortality and exacerbation of extant chronic disease worldwide. Influenza vaccination is thus fundamental to reduce the burden of disease. In this study, we describe the trend of influenza vaccination coverage in the seasons 2010/11-2020/21 among children aged < 2, 2-4 and 5-8 in Italy.

METHODS

We analyzed the trend of influenza vaccination coverage in the pediatric population in Italy from the 2010/11 to the 2020/21 season at national and regional level and observed the incidence of influenza-like illness (ILI) in the pediatric population between 2010/11 and 2020/21.

RESULTS

In the period 2010/11-2019/20 the highest value of coverage (4.5%) was reached in the age group 2-4 and 5-8 (season 2010/11 and 2011/12, respectively), while the lowest belonged to the < 2 group (1.1% in the season 2015/16). In the season 2020/2021 all the age groups reported a substantial increase of coverage compared with the previous season. The highest value (19.0%) was reported in the age group 2-4, followed by the group 5-8 and <  2 (13.1 and 9.2%, respectively). Considering the rates of annual ILI cases, the highest value for the 0-4 age group was 18.5% in the 2011/12 season; for the 5-14 age group, the highest value was 27.7% in the 2010/11 season.

CONCLUSIONS

Over the past 11 years pediatric influenza vaccination coverage in Italy has been low, with relevant differences across regions and seasons, albeit a general increase in coverage has been observed in the 2020/21 season. Universal influenza vaccination for children should be considered as a priority for the high incidence in this age group. Further research is needed to improve knowledge and comparability of coverage rates, and to identify the best practices for organizational models of delivery which can support the improvement of trends, the acceptability and accessibility by parents and awareness in stakeholders and decision makers.

Antiviral plant-derived natural products to combat RNA viruses: Targets throughout the viral life cycle

There is a need for new effective antivirals, particularly in response to the development of antiviral drug resistance and emerging RNA viruses such as SARS‐CoV‐2. Plants are a significant source of structurally diverse bioactive compounds for drug discovery suggesting that plant‐derived natural products could be developed as antiviral agents. This article reviews the antiviral activity of plant‐derived natural products against RNA viruses, with a focus on compounds targeting specific stages of the viral life cycle. A range of plant extracts and compounds have been identified with antiviral activity, often against multiple virus families suggesting they may be useful as broad‐spectrum antiviral agents. The antiviral mechanism of action of many of these phytochemicals is not fully understood and there are limited studies and clinical trials demonstrating their efficacy and toxicity in vivo. Further research is needed to evaluate the therapeutic potential of plant‐derived natural products as antiviral agents.

Nanovaccine Delivery Approaches and Advanced Delivery Systems for the Prevention of Viral Infections: From Development to Clinical Application

Viral infections causing pandemics and chronic diseases are the main culprits implicated in devastating global clinical and socioeconomic impacts, as clearly manifested during the current COVID-19 pandemic. Immunoprophylaxis via mass immunisation with vaccines has been shown to be an efficient strategy to control such viral infections, with the successful and recently accelerated development of different types of vaccines, thanks to the advanced biotechnological techniques involved in the upstream and downstream processing of these products. However, there is still much work to be done for the improvement of efficacy and safety when it comes to the choice of delivery systems, formulations, dosage form and route of administration, which are not only crucial for immunisation effectiveness, but also for vaccine stability, dose frequency, patient convenience and logistics for mass immunisation. In this review, we discuss the main vaccine delivery systems and associated challenges, as well as the recent success in developing nanomaterials-based and advanced delivery systems to tackle these challenges. Manufacturing and regulatory requirements for the development of these systems for successful clinical and marketing authorisation were also considered. Here, we comprehensively review nanovaccines from development to clinical application, which will be relevant to vaccine developers, regulators, and clinicians.

Human Influenza Epidemiology

Influenza virus infections are common in people of all ages. Epidemics occur in the winter months in temperate locations and at varying times of the year in subtropical and tropical locations. Most influenza virus infections cause mild and self-limiting disease, and around one-half of all infections occur with a fever. Only a small minority of infections lead to serious disease requiring hospitalization. During epidemics, the rates of influenza virus infections are typically highest in school-age children. The clinical severity of infections tends to increase at the extremes of age and with the presence of underlying medical conditions, and impact of epidemics is greatest in these groups. Vaccination is the most effective measure to prevent infections, and in recent years influenza vaccines have become the most frequently used vaccines in the world. Nonpharmaceutical public health measures can also be effective in reducing transmission, allowing suppression or mitigation of influenza epidemics and pandemics.

Identification of affective valence of Twitter generated sentiments during the COVID-19 outbreak

This study aims to conduct text mining of affective valence of the sentiments generated on social media during the COVID-19 and measure their association with different outcomes of the disease. 50,000 tweets per day over 23 days during the pandemic were extracted using the VADER sentiment analysis tool. Overall, tweets could effectively be classified in terms of polarity, i.e., “positive,” “negative” and “neutral” sentiments. Furthermore, on a day-to-day basis, the study identified a positive and significant relationship between COVID-19-related (a) global infections and negative tweets, (b) global deaths and negative tweets, (c) recoveries and negative tweets, and (d) recoveries and positive tweets. No significant association could be found between (e) infections and positive tweets and (f) deaths and positive tweets. Furthermore, the statistical analysis also indicated that the daily distribution of tweets based on polarity generates three distinct and significantly different numbers of tweets per category, i.e., positive, negative and neutral. As per the results generated through sentiment analysis of tweets in this study, the emergence of “positive” tweets in such a gloomy pandemic scenario shows the inherent resilience of humans. The significant association between news of COVID-19 recoveries and positive tweets seems to hint at a more optimistic scenario whenever the pandemic finally comes to an end or is controlled. Such public reactions—for good—have the potential to go viral and influence several others, especially those who are classified as “neutral” or fence-sitters.

Safety and Impact on Training of the Influenza Vaccines in Elite Athletes Participating in the Rio 2016 Olympics

OBJECTIVE

The aim of the study was to evaluate the safety and tolerance of influenza vaccines for the northern and southern hemispheres in Polish elite athletes participating in the Rio 2016 Olympics.

DESIGN

Prospective, observational, cohort study.

SETTING

Institutional level.

PARTICIPANTS

Ninety-seven athletes vaccinated only with the northern hemisphere vaccine; 98 athletes received the southern hemisphere vaccine alone, whereas 39 athletes were vaccinated with both vaccines.

INTERVENTIONS

The athletes were vaccinated with a trivalent, inactivated influenza vaccine recommended for the northern hemisphere 2015/2016 and then with the vaccine recommended for the southern hemisphere 2016. Athletes kept a diary of adverse events and effects (if any) on training for 6 days after vaccination.

MAIN OUTCOME MEASURES

The percentage of general and local adverse events, number of lost or modified training sessions.

RESULTS

Significantly more local adverse events (pain and redness) were found in the group immunized with the vaccine for the northern hemisphere. There were no differences in the frequency of general adverse events and influence on training between groups. Of total 273 athletes who had 1911 training days during 6 days after vaccination, 6 athletes (2.2%) lost 13 training days (0.7%) and 16 athletes (5.9%) had to modify 34 (1.7%) training days within first 2 days after vaccination.

CONCLUSIONS

Athletes tolerated influenza immunization well. If they are going to travel to the other hemisphere during the influenza season, the use of the second influenza vaccine should be advised. Athletes should anticipate modification of trainings for 2 days after vaccination.

Two-stage prediction model for in-hospital mortality of patients with influenza infection

BACKGROUND

Infleunza is a challenging issue in public health. The mortality and morbidity associated with epidemic and pandemic influenza puts a heavy burden on health care system. Most patients with influenza can be treated on an outpatient basis but some required critical care. It is crucial for frontline physicians to stratify influenza patients by level of risk. Therefore, this study aimed to create a prediction model for critical care and in-hospital mortality.

METHODS

This retrospective cohort study extracted data from the Chang Gung Research Database. This study included the patients who were diagnosed with influenza between 2010 and 2016. The primary outcome of this study was critical illness. The secondary analysis was to predict in-hospital mortality. A two-stage-modeling method was developed to predict hospital mortality. We constructed a multiple logistic regression model to predict the outcome of critical illness in the first stage, then S1 score were calculated. In the second stage, we used the S1 score and other data to construct a backward multiple logistic regression model. The area under the receiver operating curve was used to assess the predictive value of the model.

RESULTS

In the present study, 1680 patients met the inclusion criteria. The overall ICU admission and in-hospital mortality was 10.36% (174 patients) and 4.29% (72 patients), respectively. In stage I analysis, hypothermia (OR = 1.92), tachypnea (OR = 4.94), lower systolic blood pressure (OR = 2.35), diabetes mellitus (OR = 1.87), leukocytosis (OR = 2.22), leukopenia (OR = 2.70), and a high percentage of segmented neutrophils (OR = 2.10) were associated with ICU admission. Bandemia had the highest odds ratio in the Stage I model (OR = 5.43). In stage II analysis, C-reactive protein (OR = 1.01), blood urea nitrogen (OR = 1.02) and stage I model's S1 score were assocaited with in-hospital mortality. The area under the curve for the stage I and II model was 0.889 and 0.766, respectively.

CONCLUSIONS

The two-stage model is a efficient risk-stratification tool for predicting critical illness and mortailty. The model may be an optional tool other than qSOFA and SIRS criteria.

Inorganic and Polymeric Nanoparticles for Human Viral and Bacterial Infections Prevention and Treatment

Infectious diseases hold third place in the top 10 causes of death worldwide and were responsible for more than 6.7 million deaths in 2016. Nanomedicine is a multidisciplinary field which is based on the application of nanotechnology for medical purposes and can be defined as the use of nanomaterials for diagnosis, monitoring, control, prevention, and treatment of diseases, including infectious diseases. One of the most used nanomaterials in nanomedicine are nanoparticles, particles with a nano-scale size that show highly tunable physical and optical properties, and the capacity to a wide library of compounds. This manuscript is intended to be a comprehensive review of the available recent literature on nanoparticles used for the prevention and treatment of human infectious diseases caused by different viruses, and bacteria from a clinical point of view by basing on original articles which talk about what has been made to date and excluding commercial products, but also by highlighting what has not been still made and some clinical concepts that must be considered for futures nanoparticles-based technologies applications.

Dynamic Propagation and Impact of Pandemic Influenza A (2009 H1N1) in Children: A Detailed Review

Influenza is a highly contagious respiratory infection caused by the circulating Swine flu virus. According to the World Health Organization (WHO), the unique blending strain of influenza A H1N1 2009 (Swine Flu) is a pandemic affecting several geographical regions, including India. Previous literature indicates that children are "drivers" of influenza pandemics. At present, satisfactory data were not available to accurately estimate the role of children in the spread of influenza (in particular 2009 pandemic influenza). However, the role of children in the spread of pandemics influenza is unclear. Several studies in children have indicated that the immunization program decreased the occurrence of influenza, emphasizing the significance of communities impacted by global immunization programs. This article provides a brief overview on how children are a key contributor to pandemic Influenza A (2009 H1N1) and we would like to draw your attention to the need for a new vaccine for children to improve disease prevention and a positive impact on the community.

Influence of Influenza Infection on In-Hospital Acute Myocardial Infarction Outcomes

Influenza is associated with significant morbidity in the United States but its influence on in-hospital outcomes in patients with AMI has not been well studied. The Nationwide Readmission Database (NRD) from 2010 to 2014 was queried using the International Classification of Diseases-Ninth edition, Clinical Modification (ICD-9-CM) codes to identify all patients ≥18 years who were admitted for AMI with and without concurrent influenza. Propensity score matching was used to adjust patients' baseline characteristics and co-morbidities. In-hospital mortality, 30-day readmission rates, in-hospital complications, and resource utilization were analyzed. We identified a total of 2,428,361 patients admitted with AMI, of whom 3,006 (0.12%) had coexisting influenza. We noted significantly higher in-hospital mortality (7.7% vs 5.6%, p <0.01) and 30-day readmission rates (15.8% vs 14.1%, p <0.01) in patients with influenza compared with those without it. After propensity matching, the differences in in-hospital mortality and 30-day readmission were no longer statistically significant between the groups. Patients with influenza had a higher incidence of acute kidney injury (30.9% vs 24.6%, p <0.01), acute respiratory failure (50.2% vs 32.2%, p <0.01), need for mechanical ventilation (13.9% vs 9.2%, p <0.01), and sepsis (10% vs 3.8%, p <0.01) in the matched cohort. Patients with influenza had longer hospital stays (8.4 days vs 6.4 days, p <0.01) and mean costs of care (26,200USD vs 23,400USD, p <0.01). In conclusion, AMI patients with concomitant influenza infection had higher in-hospital mortality, 30-day readmission, in-hospital complications, and higher resource utilization compared with those without influenza.

Discovery of dihydropyrrolidones as novel inhibitors against influenza A virus

More effective prophylactic and therapeutic strategies to combat influenza viruses are urgently required worldwide because the conventional anti-influenza drugs are facing drug resistance. Here, dihydropyrrolidones (DHPs), the products of an efficient multi-components reaction, were found to possess good activities against influenza A virus (IAV). Primary structure-activity relationship indicated that the activities of DHPs were greatly influenced by substituents and four of them had IC₅₀ values lower than 10 μM (DHPs 5-2, 8, 14 and 19: IC₅₀ = 3.11-9.23 μM). The activities against multiple IAV strains and mechanism of DHPs were further investigated by using 5-2 (IC₅₀ = 3.11 μM). It was found that 5-2 possessed antiviral effects against all the investigated subtypes of IAVs with the IC₅₀ values from 3.11 to 7.13 μM. Moreover, 5-2 showed very low cytotoxicity with CC₅₀ > 400 μM. Results of mechanism study indicated that 5-2 could efficiently inhibit replication of IAV, up-regulate the expression of key antiviral cytokines IFN-β and antiviral protein MxA, and suppress the production of the NDAPH oxidase NOX1 in MDCK cells. These results indicated that 5-2 could be used as a potential inhibitor against wide subtypes of IAVs.

Factors associated with seasonal influenza self-diagnosis: a prospective observational study in Japan

This prospective observational study, conducted at a community clinic in Japan during the influenza season, from December 2017 to April 2018 aimed to investigate the accuracy of factors used for influenza self-diagnosis. Data were collected from pre-examination checklists issued to patients with suspected influenza and electronic medical records. Receiver operating characteristic (ROC) curve analysis was performed using a rapid influenza diagnostic test as the reference standard, and 2 × 2 contingency tables were analysed at each cut-off point. We analysed data from 290 patients (72.8% males, median age: 38 years, interquartile range: 26–50 years). The area under the ROC curve (AUC) for patients who were aware of other patients presumed to have influenza within close proximity was 0.74 (95% confidence interval (CI): 0.66–0.82). The AUCs for patients with a history of influenza, unvaccinated status, cough, or nasal discharge were 0.68 (95% CI: 0.60–0.75), 0.66 (95% CI: 0.59–0.73), 0.67 (95% CI: 0.59–0.75), and 0.70 (95% CI: 0.62–0.78), respectively. The sensitivity, specificity and positive likelihood ratio at a 90% cut-off point was 19.5% (95% CI: 13.5–26.6%), 94.1% (95% CI: 88.7–97.4%) and 3.31 (95% CI: 1.57–6.98). The sensitivity, specificity and negative likelihood ratio at a 10% cut-off point was 95.5% (95% CI: 90.9–98.2%), 9.6% (95% CI: 5.2–15.8%) and 0.48 (95% CI: 0.20–1.16). After multivariate logistic regression analysis, the AUC increased significantly from 0.77 (95% CI: 0.70–0.83) to 0.81 (95% CI: 0.76–0.86) when self-diagnosis-related information was added to basic clinical information. We identified factors that improve the accuracy and validity of influenza self-diagnosis. Appropriate self-diagnosis could contribute to the containment efforts during influenza epidemics and reduce its social and economic burden.

Probiotics Reduce Health Care Cost and Societal Impact of Flu-Like Respiratory Tract Infections in the USA: An Economic Modeling Study

Acute respiratory tract infections (RTIs) of viral origin place a substantial burden on health care resources and society. Randomized controlled trials have shown positive effects of probiotics on clinical outcomes in these commonly occurring RTIs. Two meta-analyses published by the York Health Economics Consortium (YHEC) and Cochrane reported the efficacy of probiotics in reducing incidence and duration of RTIs, number of antibiotic courses, and days absent from work. The aim of this study was to assess the potential health-economic impact of probiotics on RTI-associated events and expenses in the US primary care setting. A state-transition microsimulation model reproduced a study population representative of the US national demographics for age and gender (1/1,000 sample). RTI incidence was based on the influenza-like illness outpatient consultation rate reported by the Centers for Disease Control and Prevention (CDC) FluView. Data on vaccination, on factors that negatively impact RTI outcomes, on resource utilization, and on productivity loss were obtained from US national databases. Analyses were performed for both meta-analyses independently. Outcomes included cost savings for the health care payer, related to a reduced number of RTI episodes, less outpatient consultations, and decreased medical prescriptions as well as cost savings from a broader societal perspective related to productivity loss. The analysis showed that generalized probiotic intake in the US population for 2017–2018 would have allowed cost savings for the health care payer of 4.6 million USD based on the YHEC scenario and 373 million USD for the Cochrane scenario, by averting 19 million and 54.5 million RTI sick days, respectively, compared to no probiotics. Antibiotic prescriptions decreased with 1.39–2.16 million courses, whereas absence from work decreased by 3.58–4.2 million days when applying the YHEC and Cochrane data, respectively. When productivity loss is included, total savings for society represented 784 million or 1.4 billion USD for the YHEC and Cochrane scenarios, respectively. Subgroup analyses demonstrated an incremental benefit of probiotics in at-risk groups, which might be of relevance for targeted interventions. Sensitivity analyses confirmed the robustness of the model outcomes. Our analysis demonstrated a positive impact of probiotics on the health care and economic burden of flu-like RTIs. Improved disease outcomes translated into considerable cost savings for both the payer and society.

To hit or not to hit: Large-scale sequence analysis and structure characterization of influenza A NS1 unlocks new antiviral target potential

Influenza NS1 protein is among the most promising novel druggable anti-influenza target, based on its structure; multiple interactions; and global function in influenza replication and pathogenesis. Notwithstanding, drug development guidance based on NS1 structural biology is lacking. Here, we design a promising strategy directed to highly conserved druggable regions as a result of an exhaustive large-scale sequence analysis and structure characterization of NS1 protein across human-infecting influenza A subtypes, over the past 100 years. We have identified 3 druggable pockets and 8 new potential hot spot residues in the NS1 protein, not described before, additionally to other 16 sites previously identified, which represent attractive targets for pharmacological modulation. This study provides a rationale towards structure-function studies of NS1 druggable sites, which have the potential to accelerate the NS1 target validation. This research also contributes to a deeper comprehension and insight into the evolutionary dynamics of influenza A NS1 protein.

Burden of seasonal influenza in sub-Saharan Africa: a systematic review protocol

INTRODUCTION

Measures of epidemiological burdens are an important contribution to estimating disease severity and determining the at-risk populations for seasonal influenza. In the absence of these data, it is extremely difficult for policy-makers to decide on how to distribute limited resources. This systematic review will synthesise the literature on reported burden of seasonal influenza (eg, morbidity and mortality) in sub-Saharan Africa.

METHOD AND ANALYSIS

We will include published epidemiological studies that capture the burden estimation of seasonal influenza between 1 January 2000 and 31 August 2018. Studies that have reported disease burden estimates associated to influenza-like illness, acute respiratory illness, acute lower respiratory illness, severe acute respiratory illness and severe or very severe pneumonia using laboratory-confirmed influenza cases will be included. We will perform a multiple electronic database search in PubMed, Embase, African Journals Online, Cochrane, Web of science, CINAHL and Google scholar for eligible studies. The reference lists of relevant studies will also be hand-searched for potentially eligible studies. The titles and abstracts of identified records will be screened independently by two authors. The full-text articles of potentially eligible studies will be assessed independently by two authors. Discrepancies will be resolved by discussion, and by a third author if the first two authors fail to come to a consensus. The measures of the burden of influenza will be aggregated using a meta-analysis for homogeneous studies and narrative synthesis if the studies are heterogeneous. The strength of the evidence will be assessed using the Grading of Recommendations Assessment, Development and Evaluation approach.

ETHICS AND DISSEMINATION

This systematic review will use publicly available data; and as such, no formal ethical review is required. Our findings will be published in a peer-reviewed journal and also disseminated through conferences and stakeholder meetings.

PROSPERO REGISTRATION NUMBER

CRD42017074091.

The impact of influenza infection on young children, their family and the health care system

Background

Influenza is a major cause of respiratory illness in young children. Assessing the impact of infection on children and the community is required to guide immunisation policies.

Objectives

To describe the impact of laboratory‐proven influenza in young children and to compare its impact with that of other respiratory viruses on the child, their family and the health care system.

Methods

Preschool children presenting for care or admission to a tertiary paediatric hospital during the 2008‐2014 influenza seasons were tested for respiratory virus by polymerase chain reaction and culture. Parental surveys were used to determine the impact of infection on illness duration, medication use, absenteeism and health service utilisation. Multivariate regression analyses were used to assess the impact of influenza and to evaluate the association between influenza status and outcomes.

Results

Among 1191 children assessed, 238 had influenza. Among children with influenza, 87.8% were administered antipyretics and 40.9% antibiotics. 28.6% had secondary complications. 65.4% of children missed school/day care, and 53.4% of parents missed work. When influenza and other viruses were compared, significant differences were noted including duration of illness (influenza: 9.54 days, other viruses: 8.50 days; P = 0.005) and duration of absenteeism for both the child (23.1 vs 17.3 hours; P = 0.015) and their parents (28.5 vs 22.7 hours; P = 0.012).

Conclusions

Influenza infection in young children has a significant impact on medication use, absenteeism and the use of health care service. Significant differences are identified when compared with other ILI. These data demonstrate that influenza prevention strategies including immunisation are likely to have wide and significant impacts.

Self-diagnosis of seasonal influenza in a rural primary care setting in Japan: A cross sectional observational study

OBJECTIVE

To elucidate the accuracy and optimal cut-off point of self-diagnosis and clinical symptoms of seasonal influenza compared with rapid influenza diagnostic tests as the reference standard, we conducted a cross sectional observational study at a rural clinic in Japan.

METHODS

Data during three influenza seasons (December 2013 to April 2016) were retrospectively collected from the medical records and pre-examination sheets of 111 patients aged >11 years (mean age 48.1 years, men 53.2%) who were suspected of influenza infection and underwent rapid influenza diagnostic testing. Patients' characteristics (age, sex, and past medical history of influenza infection), clinical signs (axillary temperature, pulse rate, cough, joint and muscle pain, and history of fever [acute or sudden, gradual, and absence of fever]), duration from the onset of symptoms, severity of feeling sick compared with a common cold (severe, similar, and mild), self-reported likelihood of influenza (%), and results of rapid influenza diagnostic tests.

RESULTS

At the optimal cut-off point (30%) for estimation of self-diagnosis of seasonal influenza, the positive likelihood ratio (LR+) was 1.46 (95% confidence interval 1.07 to 2.00) and negative likelihood ratio (LR-) was 0.57 (0.35 to 0.93). At a 10% cut-off point, LR-was 0.33 (0.12 to 0.96). At an 80% cut-off point, LR+ was 2.75 (0.75 to 10.07). As for clinical signs, the combination of acute or sudden onset fever and cough had LR+ of 3.27 (1.68 to 6.35). Absence of cough showed LR-of 0.15 (0.04 to 0.61).

CONCLUSIONS

Self-diagnosis of influenza using the optimal cut-off point (30%) was not found useful for ruling in or ruling out an influenza diagnosis. However, it could be useful when patients self-report extremely high (80%) or low (10%) probability of having influenza. Clinically useful signs were the combination of history of fever and cough, and absence of cough.

Seasonal influenza among children diagnosed by their guardians: a small pilot study in Japan

AIM

We aimed to elucidate the accuracy and optimal cut-off point of the self-diagnosis of influenza and the associated clinical symptoms of children by their guardians, compared with those of the rapid influenza diagnostic test (RIDT).

BACKGROUND

Seasonal influenza is a common outpatient problem during the winter season. A paediatric influenza epidemic has socio-economic impacts like temporary school closure, school event cancellations, and unscheduled work absences among parents. Hence, early identification and assessment of influenza to prevent its spread is important from a societal perspective.

METHOD

We performed a cross-sectional observational study in a rural clinic in Japan every winter season from December 2013 to March 2016. We retrospectively extracted information from the medical records and pre-examination checklists of 24 patients aged <12 years (mean age, 5.4 years; men, 54.2%). The data extracted from the medical records and pre-examination checklist included the baseline characteristics (age, sex and past medical history of influenza), clinical signs and symptoms, diagnosis by guardians (%) and RIDT results.

FINDINGS

The optimal cut-off point of the self-diagnosis of influenza by guardians was 80%, with a sensitivity and specificity of 63.6% (95% confidence interval: 30.8-89.1) and 92.3% (64.0-99.8). At a 50% cut-off point, the sensitivity and specificity were 90.9% (58.7-99.8) and 53.8% (25.1-80.8). The accuracy of feeling severely sick, as estimated by the guardians showed a sensitivity and specificity of 90.9% (58.7-99.8) and 69.2% (38.6-90.9). Our study indicates that the diagnosis of seasonal influenza by guardians to their children would be useful in the establishment of both confirmatory diagnoses when it has high probability above the optimal cut-off point (80%), and exclusion diagnosis when it has low probability (50%). Not feeling severely sick, estimated by the guardians might be a useful indicator for the exclusion of paediatric influenza.

Influenza vaccination coverage of health care workers: a cross-sectional study based on data from a Swiss gynaecological hospital

Background: Pregnancy is a risk factor for severe influenza and related complications. The vaccination has been recommended in healthcare workers as a strategy for preventing influenza in risk patients. The aim of this study was to analyze the influenza vaccination rate of the department of obstetrics and gynaecology of the Cantonal hospital St. Gallen in Switzerland.

Methods: A cross-sectional study was carried out to investigate the influenza vaccination rates of all staff members of the Department of obstetrics and gynaecology (n=259). The vaccination coverage was compared according to sociodemographic variables using Chi-squared test. Associations were determined using a logistic regression model. Possible reasons for and against vaccination coverage were then investigated.

Results: 200 questionnaires were included (valid response rate 77%). 15% reported being vaccinated against influenza (n=29). Reasons to be vaccinated are the belief of protection of patients (82%), oneself (75%) or family (61%). Reasons not to get vaccinated, including beliefs regarding the vaccine is not important (49%) and its ineffectiveness (44%). In the logistic regression analysis, the vaccination coverage among doctors (61% vaccinated) and nurses/midwives (4% vaccinated) is different from the vaccination coverage among the non-medical staff reference category (16% vaccinated; p=0.004, p=0.027), after controlling for the effect of other variables sex (p=0.807), age (p=0.438) and full time employment (p=0.298).

Discussion: This study showed that doctors have a higher vaccination rate compared to other job roles, whereas the nurses and midwives had very low vaccination rates, which indicate a significant public health communication gap that needs to be addressed.

IFN and cytokine responses in ducks to genetically similar H5N1 influenza A viruses of varying pathogenicity

Ducks, the reservoir host, are generally permissive to influenza A virus infection without disease symptoms. This natural ecology was upset by the emergence of H5N1 strains, which can kill ducks. To better understand host-virus interactions in the reservoir host, and influenza strain-specific molecular contributions to virulence, we infected White Pekin ducks with three similar H5N1 viruses, with known differences in pathogenicity and replication rate. We quantified viral replication and innate immune gene activation by qPCR, in lung and spleen tissues, isolated on each of the first 3 days of infection. The three viruses replicated well, as measured by accumulation of matrix gene transcript, and viral load declined over time in the spleen. The ducks produced rapid, but temporally limited, IFN and cytokine responses, peaking on the first day post-infection. IFN and proinflammatory cytokine gene induction were greater in response to infection with the more lethal viruses, compared to an attenuated strain. We conclude that a well-regulated IFN response, with the ability to overcome early viral immune inhibition, without hyperinflammation, contributes to the ability of ducks to survive H5N1 influenza replication in their airways, and yet clear systemic infection and limit disease.

Diagnostic accuracy of the real-time PCR cobas® Liat® Influenza A/B assay and the Alere i Influenza A&B NEAR isothermal nucleic acid amplification assay for the detection of influenza using adult nasopharyngeal specimens

BACKGROUND

Accurate detection of influenza requires diagnostic testing; however, methods such as RADTs and central laboratory-based tests are limited by low sensitivity and time constraints, respectively.

OBJECTIVE

To compare the performances of the cobas^® Liat^® Influenza A/B and Alere™ i Influenza A&B point-of-care (POC) assays for detecting influenza A and B viruses using fresh nasopharyngeal specimens with the GenMark Dx^® Respiratory Viral Panel as the reference method, a FDA cleared IVD PCR test.

STUDY DESIGN

A total of 87 samples collected in viral transport medium from adults ≥18 years of age were re-tested on both POC assays (based on the reference PCR method, 29 were influenza A and 18 were influenza B virus positive).

RESULTS

The overall sensitivity and specificity of the cobas Influenza A/B for the detection of influenza A and B relative to reference PCR was 97.9% (95% confidence interval [CI] 88.9%, 99.6%) and 97.5% (95% CI: 87.1%, 99.6%), respectively, while the sensitivity of the Alere i Influenza A&B assay relative to the reference PCR method was 63.8% (95% CI: 49.5%, 76.0%) and the specificity was 97.5% (95% CI: 87.1%, 99.6%). The individual sensitivities and specificities of the cobas Influenza A/B assay for influenza A alone and influenza B alone were comparable to those of the reference PCR method (influenza A: sensitivity of 100% [95% CI: 88.3%, 100.0%] and specificity of 98.3% [95% CI: 90.9%, 99.7%]; influenza B: sensitivity of 94.4% [95% CI: 74.2%, 99.0%] and specificity of 100% [95% CI: 94.7%, 100.0%]). For the Alere i Influenza A&B assay, the individual specificities for influenza A and B were comparable to those of the reference PCR method (98.3% [95% CI: 90.9%, 99.7%] and 97.1% [95% CI: 90.0%, 99.2%], respectively), while the individual sensitivities were low relative to reference PCR (55.2% [95% CI: 37.5%, 71.6%] and 72.2% [95% CI: 49.1%, 87.5%], respectively).

CONCLUSION

The cobas Influenza A/B assay demonstrated performance equivalent to laboratory-based PCR, and could replace rapid antigen tests.

A Perspective on the Structural and Functional Constraints for Immune Evasion: Insights from Influenza Virus

Influenza virus evolves rapidly to constantly escape from natural immunity. Most humoral immune responses to influenza virus target the hemagglutinin (HA) glycoprotein, which is the major antigen on the surface of the virus. The HA is composed of a globular head domain for receptor binding and a stem domain for membrane fusion. The major antigenic sites of HA are located in the globular head subdomain, which is highly tolerant of amino acid substitutions and continual addition of glycosylation sites. Nonetheless, the evolution of the receptor-binding site and the stem region on HA is severely constrained by their functional roles in engaging the host receptor and in mediating membrane fusion, respectively. Here, we review how broadly neutralizing antibodies (bnAbs) exploit these evolutionary constraints to protect against diverse influenza strains. We also discuss the emerging role of other epitopes that are conserved only in subsets of viruses. This rapidly increasing knowledge of the evolutionary biology, immunology, structural biology, and virology of influenza virus is invaluable for development and design of more universal influenza vaccines and novel therapeutics.

Reassortment in segmented RNA viruses: mechanisms and outcomes

Segmented RNA viruses are widespread in nature and include important human, animal and plant pathogens, such as influenza viruses and rotaviruses. Although the origin of RNA virus genome segmentation remains elusive, a major consequence of this genome structure is the capacity for reassortment to occur during co-infection, whereby segments are exchanged among different viral strains. Therefore, reassortment can create viral progeny that contain genes that are derived from more than one parent, potentially conferring important fitness advantages or disadvantages to the progeny virus. However, for segmented RNA viruses that package their multiple genome segments into a single virion particle, reassortment also requires genetic compatibility between parental strains, which occurs in the form of conserved packaging signals, and the maintenance of RNA and protein interactions. In this Review, we discuss recent studies that examined the mechanisms and outcomes of reassortment for three well-studied viral families - Cystoviridae, Orthomyxoviridae and Reoviridae - and discuss how these findings provide new perspectives on the replication and evolution of segmented RNA viruses.

The cap-binding site of influenza virus protein PB2 as a drug target

The RNA polymerase of influenza virus consists of three subunits: PA, PB1 and PB2. It uses a unique `cap-snatching' mechanism for the transcription of viral mRNAs. The cap-binding domain of the PB2 subunit (PB2cap) in the viral polymerase binds the cap of a host pre-mRNA molecule, while the endonuclease of the PA subunit cleaves the RNA 10-13 nucleotides downstream from the cap. The capped RNA fragment is then used as the primer for viral mRNA transcription. The structure of PB2cap from influenza virus H1N1 A/California/07/2009 and of its complex with the cap analog m(7)GTP were solved at high resolution. Structural changes are observed in the cap-binding site of this new pandemic influenza virus strain, especially the hydrophobic interactions between the ligand and the target protein. m(7)GTP binds deeper in the pocket than some other virus strains, much deeper than the host cap-binding proteins. Analysis of the new H1N1 structures and comparisons with other structures provide new insights into the design of small-molecule inhibitors that will be effective against multiple strains of both type A and type B influenza viruses.

Generation status as a determinant of influenza vaccination among Mexican-identified adults in California, 2011-12

First generation Latinos often have better health behaviors and outcomes than second and third generation Latinos. This study examined the correlates of seasonal influenza vaccinations among Mexican-identified (Mexican) adults, who make up the largest Latino subgroup in California. A sample of Mexican adults (N = 7493) from the 2011–12 California Interview Health Survey was used to compare the odds of first, second, and third generation Mexicans receiving influenza vaccinations in the past year. We performed a logistic regression taking into account socio-demographic characteristics, health status, and access to care. We repeated the analysis after stratifying for nativity, and then age. Being a second (odds ratio (OR) = 0.74, confidence interval (CI): 0.59, 0.92) and third generation or higher (OR = 0.66, CI: 0.51, 0.86) Mexican was associated with lower odds of getting an influenza vaccination compared to first generation Mexicans. Having a chronic disease, and access to care was associated with higher odds of vaccination, while lower age was associated with lower odds of vaccination among both US-, and foreign-born Mexicans. Given that the majority of Mexicans in California are US-born, the fact that being second- and third-generation Mexicans was associated with lower influenza vaccination rates is of significant concern.

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Among Mexicans in California being second and third generation was associated with lower odds of vaccination.

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Being under 65 was associated with lower odds of vaccination.

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Correlates of vaccination varied by nativity and age.

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Second and third generation Mexicans should be targets of flu vaccination campaigns.

DAMPs and influenza virus infection in ageing

Influenza A virus (IAV) is a serious global health problem worldwide due to frequent and severe outbreaks. IAV causes significant morbidity and mortality in the elderly population, due to the ineffectiveness of the vaccine and the alteration of T cell immunity with ageing. The cellular and molecular link between ageing and virus infection is unclear and it is possible that damage associated molecular patterns (DAMPs) may play a role in the raised severity and susceptibility of virus infections in the elderly. DAMPs which are released from damaged cells following activation, injury or cell death can activate the immune response through the stimulation of the inflammasome through several types of receptors found on the plasma membrane, inside endosomes after endocytosis as well as in the cytosol. In this review, the detriment in the immune system during ageing and the links between influenza virus infection and ageing will be discussed. In addition, the role of DAMPs such as HMGB1 and S100/Annexin in ageing, and the enhanced morbidity and mortality to severe influenza infection in ageing will be highlighted.

Hyporeactivity of Alveolar Macrophages and Higher Respiratory Cell Permissivity Characterize DBA/2J Mice Infected by Influenza A Virus

Influenza A virus remains a major public health problem. Mouse models have been widely used to study influenza infection in mammals. DBA/2J and C57BL/6J represent extremes in terms of susceptibility to influenza A infection among inbred laboratory mouse strains. Several studies focused specifically on the factors responsible for the susceptibility of DBA/2J or the resistance of C57BL/6J and resulted in impressive lists of candidate genes or factors over- or underexpressed in one of the strains. We adopted a different phenotypical approach to identify the critical steps of the infection process accounting for the differences between DBA/2J and C57BL/6J strains. We concluded that both a dysfunction of alveolar macrophages and an increased permissivity of respiratory cells rendered DBA/2J more susceptible to influenza infection.