Complications of viral influenza

Vaccine microarray patch self-administration: A preliminary study in adults 50 years of age and over

INTRODUCTION

We assessed the safety, performance, acceptability, and usability of the High-Density Microarray Patch (HD-MAP) for vaccination in adults aged 50 and over.

METHODS

This study was a single-centre, open-label, single-arm intervention in healthy adults aged 50+. HD-MAPs (vaccine-free) were applied by a trained user and self-administered. Participants received one excipient-coated HD-MAP to the volar forearm (FA) and the upper arm (UA) administered by a trained user. Participants then self-administered a HD-MAP to the FA and UA. Application sites were compared for skin response. Participants completed an online survey and participated in a semi-structured interview on acceptability and usability. Analyses were undertaken using descriptive statistics. Interviews were coded in NVivo 12 and subject to thematic analysis. The study occurred from 8 September 2021 to 15 February 2022 in Brisbane, Australia.

RESULTS

Of 44 participants, 43 % (n = 19) were male, and 57 % (n = 25) female. The HD-MAP was well-tolerated, with no treatment-related serious adverse events. The increase in transepidermal water loss following self-administration was similar to that observed for trained user administration (UA: 7.5 fold vs 6-fold, FA: 6.1-fold vs 6.6 fold). Fluorescent dermatoscopy confirmed that HD-MAPs engaged with the skin surface and that self and trained user administrations were similar. All participants found the HD-MAP applicator easy to use. 82 % of participants preferred "vaccination" by HD-MAP should its efficacy be proven equivalent to intramuscular injection (IM). Participants reported high acceptance of the resulting transient marks on the skin (82 %). 98 % of participants agreed that self-administration of the HD-MAP at home, without supervision, was highly preferable for its convenience.

CONCLUSION

HD-MAPs were safe in adults 50+ years, and performance was effective, regardless of administrator. Participants preferred the HD-MAP for its ease of use and convenience in self-administration. This vaccine delivery method shows promise for future implementation for this population.

Safety Assessment of Influenza Vaccination for Neurological Outcomes Among Older Adults in Japan: A Self-Controlled Case Series Study

PURPOSE

To assess adverse neurological risks following influenza vaccination in older adults.

METHODS

Using a linked database of healthcare administrative claims data and vaccination records from an urban city in Japan (April 1, 2014, to March 31, 2020), we conducted an observational study utilizing a self-controlled case series design. We identified individuals aged ≥ 65 years who experienced adverse neurological outcomes, defined as hospitalizations related to epilepsy, paralysis, facial paralysis, neuralgia, neuritis, optic neuritis, migraine, extrapyramidal disorders, Guillain-Barre syndrome, or narcolepsy. We used conditional Poisson regression to analyze within-subject incidence rate ratios, comparing the risk of these outcomes during risk periods following influenza vaccination (0-6 days and 7-29 days after each vaccination) with nonvaccination periods. Our analysis was adjusted for age and season groups as time-varying covariates.

RESULTS

We enrolled 3283 eligible individuals (men: 1643; mean [standard deviation] age: 76 [7.3] years). The incidence rate ratio for the outcome during the risk periods was 0.93 (95% confidence interval, 0.66-1.30) in risk period 1 (0-6 days after vaccination) and 1.14 (0.96-1.35) in risk period 2 (7-29 days after vaccination), respectively.

CONCLUSIONS

We found no evidence that the risk of adverse neurological events was increased after influenza vaccination in older adults. These results may help reassure older adults who are hesitant to receive influenza vaccination because of concerns regarding adverse neurological outcomes.

Comparative Evaluation of Three Rapid Influenza Diagnostic Tests for Detection of Influenza A and B Viruses Using RT-PCR as Reference Method

To evaluate the performance of three rapid influenza diagnostic tests (RIDTs) for detecting influenza A and B viruses compared to RT-PCR. A total of 291 subjects with acute respiratory infections were enrolled. Respiratory specimens were collected and tested for influenza A and B viruses using three RIDTs. The results were compared with those obtained using an RT-PCR assay from Shanghai Berger Medical Technology Co. Ltd. as the reference method. Among the 291 subjects, 119 (40.9%) tested positive for influenza A virus and 38 (13.1%) for influenza B virus by RT-PCR. The sensitivities of the three RIDTs for influenza A virus were 92.4%, 89.1%, and 79.8%, respectively, while their specificities were 98.8%, 98.8%, and 100%, respectively. For influenza B virus, the sensitivities of the three RIDTs were 92.1%, 92.1%, and 73.7%, respectively, and their specificities were 100%, 100%, and 100%, respectively. The positive predictive values (PPVs) for influenza A virus were 98.2%, 98.1%, and 100%, respectively, while the negative predictive values (NPVs) were 94.5%, 92.4%, and 86.9%, respectively. For influenza B virus, the PPVs were all 100%, and the NPVs were 99.2%, 99.2%, and 97.7%, respectively. The three evaluated RIDTs demonstrated high specificity but varied sensitivity for detecting influenza A and B viruses. Negative results from RIDTs should be confirmed by RT-PCR, especially during peak influenza seasons. The high PPVs suggest that positive RIDT results are reliable for influenza diagnosis, while the high NPVs indicate that negative results are more likely to be true negatives.

Estimating influenza vaccine effectiveness among older adults using an integrated administrative database and the implications of potential bias: A population-based cohort study in Japan

BACKGROUND

Japan lacks an established framework for routine seasonal influenza vaccine effectiveness (SIVE) assessment at the national and municipal levels. This study aimed to estimate SIVE among older adults using an innovative population-based administrative database linking medical fee claims data with vaccination records, while also exploring its potential bias.

METHODS

In this retrospective population-based cohort study, we assessed SIVE against medically attended influenza during the 2017/18 season among older adults aged ≥65 years in a Japanese city. A Cox proportional hazards model was used to estimate hazard rate ratios, treating vaccination status as time-dependent. To explore potential biases, multivariate logistic regression analysis was used to investigate the association between vaccination status and acute respiratory infection (ARI) diagnosis and trauma/injury during the non-influenza season.

RESULTS

This study included 82 % (n = 110,892) of the city's older adult population, with 39.7 % vaccination coverage. The estimated SIVE was 2.9 % (95 % confidence interval: -6.2-11.2), showing no statistical significance. Similarly, subgroup analyses by age and comorbidities revealed no significant protective effect of SIVE. In the non-season analysis, adjusted odds ratios of vaccination were significantly higher for ARI [1.3 (1.3-1.4)] and trauma/injury [1.2 (1.1-1.2)]. However, no significance was observed for hospitalizations with these diagnoses, which include severe conditions less associated with healthcare-seeking behaviors [0.9 (0.8-1.1) and 0.8 (0.6-1.0), respectively].

CONCLUSIONS

No significant SIVE was observed during the 2017/18 season. Our real-world observational study, based on medical fee claims data, indicates a potential underestimation of SIVE owing to bias related to healthcare-seeking behaviors.

Sorbicillinoid HSL-2 inhibits the infection of influenza A virus via interaction with the PPAR-γ/NF-κB pathway

BACKGROUND

Drug resistance is an important factor in the fight against influenza A virus (IAV). Natural products offer a rich source of lead compounds for the discovery of novel antiviral drugs. In a previous study, we isolated the sorbicillinoid polyketide HSL-2 from the mycelium of fungus Trichoderma sp. T-4-1. Here, we show that this compound exerts strong antiviral activity against a panel of IAVs.

METHODS

The immunofluorescence and qRT-PCR assays were used to detect the inhibitory effect of HSL-2 toward the replication of influenza virus and IAV-induced expression of the pro-inflammatory cytokines such as TNF-α, IL-6, and IL-1β.

RESULTS

The results indicated that HSL-2 inhibited influenza virus replication, and it significantly inhibited IAV-induced overexpression of the pro-inflammatory cytokines TNF-α, IL-6, and IL-1β through modulating the PPAR-γ/NF-κB pathway. Notably, this effect was decreased when cells were transfected with PPAR-γ siRNA or treated with the PPAR-γ inhibitor T0070907. In addition, HSL-2 was able to attenuate lung inflammatory responses and to improve lung lesions in a mouse model of IAV infection.

CONCLUSIONS

In this paper, we identified a microbial secondary metabolite, HSL-2, with anti-influenza virus activity. This report is the first to describe the antiviral activity and mechanism of action of HSL-2, and it provides a new strategy for the development of novel anti-influenza virus drugs from natural sources.

Sacbrood viruses and select Lake Sinai virus variants dominated Apis mellifera colonies symptomatic for European foulbrood

European foulbrood (EFB) is a prevalent disease in the European honey bee (Apis mellifera) in the United States, which can lead to colony decline and collapse. The bacterial components of EFB are well-studied, but the diversity of viral infections within infected colonies has not been explored. In this study, we use meta-transcriptomics sequencing of 12 honey bee hives, symptomatic (+, n = 6) and asymptomatic (-, n = 6) for EFB, to investigate viral infection associated with the disease. We assembled 41 viral genomes, belonging to three families (Iflaviridae, Dicistroviridae, and Sinhaliviridae), all previously reported in honey bees, including Lake Sinai virus, deformed wing virus, sacbrood virus, Black queen cell virus, and Israeli acute paralysis virus. In colonies with severe EFB, we observed a higher occurrence of viral genomes (34 genomes) in contrast to fewer recovered from healthy colonies (seven genomes) and a complete absence of Dicistroviridae genomes.We observed specific Lake Sinai virus clades associated exclusively with EFB + or EFB - colonies, in addition to EFB-afflicted colonies that exhibited an increase in relative abundance of sacbrood viruses. Multivariate analyses highlighted that a combination of site and EFB disease status influenced RNA virome composition, while EFB status alone did not significantly impact it, presenting a challenge for comparisons between colonies kept in different yards. These findings contribute to the understanding of viral dynamics in honey bee colonies compromised by EFB and underscore the need for future investigations to consider viral composition when investigating EFB.IMPORTANCEThis study on the viromes of honey bee colonies affected by European foulbrood (EFB) sheds light on the dynamics of viral populations in bee colonies in the context of a prevalent bacterial brood disease. The identification of distinct Lake Sinai virus and sacbrood virus clades associated with colonies affected by severe EFB suggests a potential connection between viral composition and disease status, emphasizing the need for further investigation into the role of viruses during EFB infection. The observed increase in sacbrood viruses during EFB infection suggests a potential viral dysbiosis, with potential implications for honey bee brood health. These findings contribute valuable insights related to beekeeping practices, offering a foundation for future research aimed at understanding and mitigating the impact of bacterial and viral infection in commercial honey bee operations and the management of EFB.

Clinical significance of lower respiratory tract culture within 48 h of admission in patients with viral pneumonia: an observational study

BACKGROUND

The aim of this retrospective study was to examine the risk factors of positive lower respiratory tract cultures and to investigate whether nosocomial infections are common in patients with positive lower respiratory tract cultures.

METHODS

We enrolled 86 patients diagnosed with influenza A-related critical illness who were treated at Fuzhou Pulmonary Hospital of Fujian in China between 1st October 2013 and 31st March 2019. The of admission were used to divide the enrolled patients into two groups. Sputum and bronchoalveolar lavage fluid specimens were collected within 48 h after admission for culture. All samples were cultured immediately after sampling. Nosocomial infections are defined as any symptom or sign of pulmonary infiltration, confirmed by X-ray, after 5 days of admission and positive results from one or more cultures.

RESULTS

The average age of this cohort was (54.13 ± 16.52) years. Based on the culture results, Staphylococcus aureus and Candida albicans had the highest positive rates (3.40% (3/86) and 20.90% (18/86), respectively). In patients with positive lower respiratory tract cultures, the incidence of nosocomial infection was 73.30% (22/30) five days after admission. However, the incidence of nosocomial infection was lower (42.80%, 24/56) in patients with negative lower respiratory tract cultures. Hemoptysis, systolic pressure at admission, and blood urea nitrogen level at admission were all independent risk factors for positive lower respiratory tract cultures within 48 h of admission.

CONCLUSION

Our data showed that a significant proportion of patients with pneumonia exhibited co-infections with bacteria or fungi within five days of hospital admission. Hemoptysis, systolic pressure, and blood urea nitrogen levels at admission emerged as the key risk factors. These findings underscore the necessity of closely monitoring patients with influenza infection, particularly for positive bacterial or fungal cultures within the initial 48 h of admission.

CRP/Neopterin Ratio and Neuropsychiatric Symptoms in Patients with Different Forms of Pneumonia: Results of a Pilot Study

BACKGROUND

Pneumonia is one of the most common infectious diseases, mostly caused by viruses or bacteria. In response to bacteria or viruses which are different but which also are partly overlapping, innate and adaptive immune responses are induced, which can be quantified using the determination of specific biomarkers. Among these, C-reactive protein (CRP) has been established as a marker of innate immune function, whereas Neopterin, which is mainly produced upon stimulation with interferon-gamma, reflects cellular immune activation.

AIM

We investigated inflammation markers in patients with microbiologically confirmed viral or bacterial pneumonia, and studied the potential of CRP, Neopterin, and the CRP/Neopterin ratio to distinguish between viral and bacterial pathogenesis. Furthermore, we examined, how often neuropsychiatric symptoms occur in patients suffering from different kinds of pneumonia.

PATIENTS AND METHOD

A total of 194 patients diagnosed with either coronavirus disease 2019 (COVID-19) (n = 63), bacterial pneumonia (n = 58), Influenza infection (n = 10), Influenza and a bacterial superinfection (n = 9), and COVID-19 patients with a bacterial superinfection (n = 54) were included in our pilot study. Clinical as well as laboratory parameters were determined shortly after admission.

RESULTS

We found significantly higher CRP/Neopterin ratios in patients with bacterial pneumonia (median: 0.34) and lower CRP/Neopterin ratios in patients hospitalized with COVID-19 infection (median: 0.03; p < 0.001). Both in men and in women, the CRP/Neopterin ratio was able to distinguish between viral and bacterial pathogens, but also was able to detect bacterial super-infection (BSI) in subjects with initial viral pneumonia (p < 0.001). Patients with BSI presented with significantly lower CRP/Neopterin ratios (median 0.08) than patients with bacterial infection only (median 0.34; p < 0.001). Interestingly, COVID-19 patients had a decreased physical functioning (as reflected in the ECOG score) and a higher frequency of fatigue (84.1%) and neurological symptoms (54.8%) than patients with pneumonia, due to other underlying pathogens. Patients that reported fatigue during viral and bacterial pneumonia presented with lower CRP concentrations than patients without it.

CONCLUSIONS

The CRP/Neopterin ratio is useful to differentiate between viral and bacterial pathogenesis. The occurrence of neuropsychiatric symptoms in pneumonia appears to depend on the kind of pathogen causing the infection. Lower CRP concentrations at admission appear to be related to fatigue during acute viral and bacterial infection.

Influenza Vaccine Effectiveness Pre-pandemic Among Adults Hospitalized With Congestive Heart Failure or Chronic Obstructive Pulmonary Disease and Older Adults

BACKGROUND

Data are limited on influenza vaccine effectiveness (VE) in the prevention of influenza-related hospitalizations in older adults and those with underlying high-risk comorbidities.

METHODS

We conducted a prospective, test-negative, case-control study at 2 US hospitals from October 2018-March 2020 among adults aged ≥50 years hospitalized with acute respiratory illnesses (ARIs) and adults ≥18 years admitted with congestive heart failure (CHF) or chronic obstructive pulmonary disease (COPD) exacerbations. Adults were eligible if they resided in 1 of 8 counties in metropolitan Atlanta, Georgia. Nasopharyngeal and oropharyngeal swabs were tested using BioFire FilmArray (bioMérieux, Inc.) respiratory panel, and standard-of-care molecular results were included when available. Influenza vaccination history was determined from the Georgia vaccine registry and medical records. We used multivariable logistic regression to control for potential confounders and to determine 95% confidence intervals (CIs).

RESULTS

Among 3090 eligible adults, 1562 (50.6%) were enrolled. Of the 1515 with influenza vaccination history available, 701 (46.2%) had received vaccination during that season. Influenza was identified in 37 (5.3%) vaccinated versus 78 (9.6%) unvaccinated participants. After adjustment for age, race/ethnicity, immunosuppression, month, and season, pooled VE for any influenza-related hospitalization in the eligible study population was 63.1% (95% CI, 43.8-75.8%). Adjusted VE against influenza-related hospitalization for ARI in adults ≥50 years was 55.9% (29.9-72.3%) and adjusted VE against influenza-related CHF/COPD exacerbation in adults ≥18 years was 80.3% (36.3-93.9%).

CONCLUSIONS

Influenza vaccination was effective in preventing influenza-related hospitalizations in adults aged ≥50 years and those with CHF/COPD exacerbations during the 2018-2020 seasons.

Influenza-Associated Outcomes and Healthcare Utilization by Race and Ethnicity in the USA: a Retrospective Cohort Study Using the National Inpatient Sample Database

BACKGROUND

The influenza virus continues to be a public health concern every season. We aimed to evaluate influenza-associated outcomes and healthcare utilization by race and ethnicity.

METHODS

We conducted a retrospective cohort study using the National Inpatient Sample across 2019 and 2020. Influenza pneumonia was selected as the principal diagnosis. Outcomes included mortality, use of respiratory support ventilation, length of stay, and total hospitalization charge. Regression models were adjusted for age, gender, Charlson Comorbidity Index, hospitals' region, bed size, teaching status, insurance status, and median income.

RESULTS

We identified 73,098 individuals hospitalized with influenza pneumonia; 39,807 and 33,291 were admitted in 2019 and 2020, respectively. The sample included 49,829 (68%) White, 11,356 (15.5%) Black, 7526 (10%) Hispanic, 1860 (2.5%) Asian/Pacific, and 617 (0.84%) Native American patients. In-hospital mortality rates and respiratory support (non-invasive ventilation and invasive mechanical ventilation) in 2019 and 2020 were not significantly different across all the races. In 2019 and 2020, the adjusted odds ratios of in-patient mortality were not significantly different. Asians had higher odds of receiving NIV in 2019 but not in 2020 compared to White patients (adjusted odds ratio (aOR) 1.67, p value 0.04). The adjusted odds ratios for receiving IMV were not significantly different between the races in 2019 and 2020.

CONCLUSIONS

This study contributes valuable insight into influenza-associated outcomes and healthcare utilization patterns among diverse racial and ethnic groups. Disparities in healthcare utilization were observed among younger (< 65 years) individuals of Black and Hispanic ethnicity.

Vitamin D and immune system

The active metabolite of vitamin D 1,25(OH)2D is well known for its role in regulating calcium-phosphate homeostasis of the human body. However, the immunomodulating activity of 1,25(OH)2D has been known for many years. There are numerous reports correlating low vitamin D levels in blood serum with the onset of autoimmune diseases and with the severe course of acute infections. In this chapter, we address the role of 1,25(OH)2D in these diseases, and we discuss the possible mechanisms of action of 1,25(OH)2D in immune cells.

The Birth of the Contextual Health Education Readability Score in an Examination of Online Influenza Patient Education Materials

Introduction Influenza is a major global health concern, with its rapid spread and mutation rate posing significant challenges in public health education and communication. Effective patient education materials (PEMs) are crucial for informed decision-making and improved health outcomes. This study evaluates the efficacy of online influenza PEMs using traditional readability tools and introduces the Contextual Health Education Readability Score (CHERS) to address the limitations of existing methods that do not capture the diverse array of visual and thematic means displayed. Materials and methods A comprehensive search was conducted to select relevant online influenza PEMs. This involved looking through Google's first two pages of results sorted by relevance, for a total of 20 results. These materials were evaluated using established readability tools (e.g., Flesch Reading Ease, Flesch-Kincaid Grade Level) and the Patient Education Materials Assessment Tool (PEMAT) for understandability and actionability. The study also involved the creation of CHERS, integrating factors such as semantic complexity, cultural relevance, and visual aid effectiveness. The development of CHERS included weighting each component based on its impact on readability and comprehension. Results The traditional readability tools demonstrated significant variability in the readability of the selected materials. The PEMAT analysis revealed general trends toward clarity in purpose and use of everyday language but indicated a need for improvement in summaries and visual aids. The CHERS formula was calculated as follows: CHERS = (0.4 × Average Sentence Length) + (0.3 × Average Syllables per Word) + (0.15 × Semantic Complexity Score) + (0.1 × Cultural Relevance Score) + (0.05 × Visual Aid Effectiveness Score), integrating multiple dimensions beyond traditional readability metrics. Discussion The study highlighted the limitations of traditional readability tools in assessing the complexity and cultural relevance of health information. The introduction of CHERS addressed these gaps by incorporating additional dimensions crucial for understanding in a healthcare context. The recommendations provided for creating effective influenza PEMs focused on language simplicity, cultural sensitivity, and actionability. This may enable further research into evaluating current PEMs and clarifying means of creating more effective content in the future. Conclusions The study underscores the need for comprehensive readability assessments in PEMs. The creation of CHERS marks a significant advancement in this field, providing a more holistic approach to evaluating health literacy materials. Its application could lead to the development of more inclusive and effective educational content, thereby improving public health outcomes and reducing the global burden of influenza. Future research should focus on further validating CHERS and exploring its applicability to other health conditions.

Excess hospitalizations and in-hospital mortality associated with seasonal influenza in Italy: a 11-year retrospective study

BACKGROUND

Influenza and flu-like syndromes are difficult to monitor because the symptoms are not specific, laboratory tests are not routinely performed, and diagnosis codes are often lacking or incompletely registered in medical records. This may result in an underestimation of hospital admissions, associated costs, and in-hospital mortality. Therefore, this study aimed to estimate the public health and economic burden of hospitalisations associated with influenza in Italy, at the national and regional levels.

METHODS

This 11-year retrospective study included patients admitted to hospitals for influenza or diagnoses associated with influenza (including respiratory and cardiocirculatory conditions) from 2008/09 to 2018/19. Data on hospitalisations were extracted from the Italian Hospital Discharge Records. Information on weekly influenza-like syndrome incidence and weekly average temperature were used to estimate the burden of influenza in terms of hospital admissions in every Italian region and for different age groups by applying a negative binomial model. The model was also applied to estimate in-hospital mortality and the total costs of influenza and influenza-like hospital admissions.

RESULTS

Over the study period, in addition to 3,970 average seasonal admissions coded as influenza, we estimated an average of 21,500 excess hospitalization associated with influenza per season, which corresponds to 36.4 cases per 100,000. Most of the excess hospitalisations concerned older individuals (> 65 years) and children (0-4 years) with 86 and 125 cases per 100,000, respectively. Large variations were observed across regions. Overall, the total estimated hospital burden associated with influenza (including respiratory and cardiocirculatory conditions) was approximately €123 m per year. While the in-hospital mortality for admissions with a primary diagnosis of influenza was very low (~ 150 cases per season), cases increased dramatically for primary diagnoses of influenza and pneumonia (about 9,500 cases per season). The average seasonal in-hospital deaths attributable to influenza were equal to 2,775 cases.

CONCLUSIONS

Our findings suggest a remarkable underestimation of the burden of influenza, mostly in the older population but not neglectable in younger individuals. Our results may aid the management of current and future flu seasons and should be used for policy making (e.g., vaccine strategies) and operation management choices (e.g., planning and staffing beds during influenza peaks). Overall, the present study supports the need for increased testing for influenza in Italy to tackle the current underestimation of influenza burden.

Changes in Epidemiology and Antibiotic Prescription of Influenza: Before and after the Emergence of COVID-19

BACKGROUND

The appearance of COVID-19 had a major impact on healthcare and the epidemiology of other diseases. Following the cessation of non-pharmacologic interventions destined to limit the spread of COVID-19, influenza reemerged. The aim of this study was to compare the pre-pandemic influenza seasons with the influenza seasons after the emergence of the COVID-19 pandemic, and to identify differences in terms of clinical characteristics, risk factors, complications, outcomes, and antiviral and antibiotic treatments.

METHODS

We conducted a retrospective cohort study from the Teaching Hospital of Infectious Diseases database in Cluj-Napoca, Romania. We analyzed four pre-pandemic seasons and the seasons after the onset of COVID-19. We included adult patients hospitalized with confirmed influenza between October 2016 and August 2023. Variables such as age, sex, duration of hospitalization, severity, clinical manifestations, comorbidities, and Charlson comorbidity index were assessed.

RESULTS

A total of 941 patients were included in the analysis. The percentage of severe influenza was similar in both groups, but mortality from influenza was significantly lower after 2022. Virtually all patients were prescribed antivirals; antibiotic prescriptions decreased in the post-COVID-19 influenza seasons.

CONCLUSION

The present study suggests that influenza seasons after 2022 had lower mortality and attenuated clinical presentation.

Transcriptomic Analysis Reveals Sixteen Potential Genes Associated with the Successful Differentiation of Antibody-Secreting Cells through the Utilization of Unfolded Protein Response Mechanisms in Robust Responders to the Influenza Vaccine

The seasonal influenza vaccine remains one of the vital recommended infection control measures for the elderly with chronic illnesses. We investigated the immunogenicity of a single dose of influenza vaccine in 123 seronegative participants and classified them into four distinct groups, determined by the promptness of vaccine response, the longevity of humoral immunity, and the likelihood of exhibiting cross-reactivity. Subsequently, we used transcriptional profiling and differential gene expression analysis to identify potential genes directly associated with the robust response to the vaccine. The group of exemplary vaccine responders differentially expressed 16 genes, namely: MZB1, MYDGF, TXNDC5, TXNDC11, HSP90B1, FKBP11, PDIA5, PRDX4, CD38, SDC1, TNFRSF17, TNFRSF13B, PAX5, POU2AF1, IRF4, and XBP1. Our findings point out a list of expressed proteins that are related to B cell proliferation, unfolded protein response, and cellular haemostasis, as well as a linkage of these expressions to the survival of long-lived plasma cells.

Longitudinal analysis of influenza vaccination implicates regulation of RIG-I signaling by DNA methylation

Influenza virus infection alters the promoter DNA methylation of key immune response-related genes, including type-1 interferons and proinflammatory cytokines. However, less is known about the effect of the influenza vaccine on the epigenome. We utilized a targeted DNA methylation approach to study the longitudinal effects (day 0 pre-vaccination and day 28 post-vaccination) on influenza vaccination responses in peripheral blood mononuclear cells. We found that baseline, pre-vaccination methylation profiles are associated with pre-existing, protective serological immunity. Additionally, we identified 481 sites that were differentially methylated between baseline and day 28 post-vaccination. These were enriched for genes involved in the regulation of the RIG-I signaling pathway, an important regulator of viral responses. Our results suggest that DNA methylation changes to components of the RIG-I pathway are associated with vaccine effectiveness. Therefore, immunization strategies that target this pathway may improve serological responses to influenza vaccination.

The chemokine receptor CXCR3 promotes CD8+ T cell-dependent lung pathology during influenza pathogenesis

The dual role of CD8+ T cells in influenza control and lung pathology is increasingly appreciated. To explore whether protective and pathological functions can be linked to specific subsets, we dissected CD8+ T responses in influenza-infected murine lungs. Our single-cell RNA-sequencing (scRNA-seq) analysis revealed notable diversity in CD8+ T subpopulations during peak viral load and infection-resolved state. While enrichment of a Cxcr3hi CD8+ T effector subset was associated with a more robust cytotoxic response, both CD8+ T effector and central memory exhibited equally potent effector potential. The scRNA-seq analysis identified unique regulons regulating the cytotoxic response in CD8+ T cells. The late-stage CD8+ T blockade in influenza-cleared lungs or continuous CXCR3 blockade mitigated lung injury without affecting viral clearance. Furthermore, adoptive transfer of wild-type CD8+ T cells exacerbated influenza lung pathology in Cxcr3-/- mice. Collectively, our data imply that CXCR3 interception could have a therapeutic effect in preventing influenza-linked lung injury.

Economic burden and secondary complications of influenza-related hospitalization among adults in the US: a retrospective cohort study

OBJECTIVE

This study aims to describe the healthcare resource utilization (HCRU) and direct medical cost of influenza-related hospitalizations to illustrate the persistent economic burden of influenza among adults in the US.

METHODS

A retrospective cohort study was conducted using the PINC AI Healthcare Database. Adults hospitalized with a diagnosis of influenza between August 1-May 31 from 2016-2023 were identified and stratified by age (18-49, 50-64 and ≥65 years). The index hospitalization was defined as the individual's first influenza-related hospitalization during each season. Patient demographics, comorbidities, and hospitalization characteristics were assessed during the index hospitalization. Index hospitalization length of stay (LOS), in-hospital mortality, intensive care unit (ICU) admissions, mechanical ventilation (MV) usage, and costs were evaluated overall and by MV usage, ICU admission, and secondary complication status. Pre-index influenza-related outpatient and emergency department (ED) visits (7 days prior) were also evaluated.

RESULTS

Primarily initiated in the ED, the median LOS for influenza-related hospitalizations was 3-4 days. Inpatient mortality increased with age (2.2-4.4%). Combined mean hospitalization and initial ED visit costs were $12,556-$14,494 (2017/18; high severity season) and $11,384-$12,896 (2022/23; most recent season). Compared to other age groups, adults ≥65 years had higher proportions of hospitalization with no MV or ICU usage. Adults 18-49 years had the highest proportion of ICU admission only, whereas adults 50-64 years had the highest MV usage only and both MV and ICU admission. MV and/or ICU usage was associated with higher hospitalization costs. Increasing proportionally with age, the majority of influenza-related hospitalizations had a secondary complication diagnosis, which were associated with elevated costs.

LIMITATIONS

Analysis of this hospital-based administrative database relied on coding accuracy. Only hospital system-associated outpatient/ED visits were captured; the full scope of HCRU was under-ascertained.

CONCLUSIONS

The economic burden of influenza-related hospitalizations remains substantial, driven by underlying conditions, MV/ICU usage and secondary complications.

Germacrone: A Multi-targeting Sesquiterpene with Promising Anti-cancer and Chronic Disease Applications

BACKGROUND

Germacrone, a naturally occurring active compound found in essential oils extracted from medicinal plants within the Zingiberaceae family, has garnered attention for its potential therapeutic applications. Extensive research has highlighted its multi-targeting capabilities, positioning it as a promising treatment for various chronic diseases, including cancer, cardiovascular conditions, and neurodegenerative disorders like Alzheimer's disease.

OBJECTIVE

This review aims to provide a comprehensive overview of germacrone as a scaffold for developing multi-targeting drugs with therapeutic potential against a range of chronic disorders. The study delves into the molecular mechanisms that underlie the therapeutic effects of germacrone and explores its potential targets, including NF-κB, PI3K/AKT/mTOR, p53, JAK/STAT, caspase, apoptosis, and autophagy induction.

METHODS

A systematic review of literature databases was conducted to gather relevant studies on germacrone and its therapeutic applications. The molecular mechanisms and potential targets of germacrone were examined to elucidate its multi-targeting capabilities.

RESULTS

Germacrone exhibits significant potential in the management of chronic diseases, with demonstrated effects on various cellular pathways. The review highlights its impact on NF-κB, PI3K/AKT/mTOR, p53, JAK/STAT, caspase, apoptosis, and autophagy induction, showcasing its versatility in targeting multiple pathways associated with chronic conditions. Germacrone has emerged as a promising candidate for the treatment of diverse chronic diseases. The understanding of its multi-targeting capabilities, coupled with its natural origin, positions it as a valuable scaffold for developing therapeutics.

CONCLUSION

The exploration of germacrone as a structural framework for multi-targeting drugs offers a potential avenue to enhance efficacy while minimizing potential side effects. Further research and clinical trials are warranted to validate the therapeutic potential of germacrone in diverse medical contexts.

Comparative Pathology of Animal Models for Influenza A Virus Infection

Animal models are essential for studying disease pathogenesis and to test the efficacy and safety of new vaccines and therapeutics. For most diseases, there is no single model that can recapitulate all features of the human condition, so it is vital to understand the advantages and disadvantages of each. The purpose of this review is to describe popular comparative animal models, including mice, ferrets, hamsters, and non-human primates (NHPs), that are being used to study clinical and pathological changes caused by influenza A virus infection with the aim to aid in appropriate model selection for disease modeling.

Differential effects of microRNAs miR-21, miR-99 and miR-145 on lung regeneration and inflammation during recovery from influenza pneumonia

In a mouse model of influenza pneumonia, we previously documented that proliferating alveolar type II (AT2) cells are the major stem cells involved in early lung recovery. Profiling of microRNAs revealed significant dysregulation of specific ones, including miR-21 and miR-99a. Moreover, miR-145 is known to exhibit antagonism to miR-21. This follow-up study investigated the roles of microRNAs miR-21, miR-99a, and miR-145 in the murine pulmonary regenerative process and inflammation during influenza pneumonia. Inhibition of miR-21 resulted in severe morbidity, and in significantly decreased proliferating AT2 cells due to impaired transition from innate to adaptive immune responses. Knockdown of miR-99a culminated in moderate morbidity, with a significant increase in proliferating AT2 cells that may be linked to PTEN downregulation. In contrast, miR-145 antagonism did not impact morbidity nor the proliferating AT2 cell population, and was associated with downregulation of TNF-alpha, IL1-beta, YM1, and LY6G. Hence, a complex interplay exists between expression of specific miRNAs, lung regeneration, and inflammation during recovery from influenza pneumonia. Inhibition of miR-21 and miR-99a (but not miR-145) can lead to deleterious cellular and molecular effects on pulmonary repair and inflammatory processes during influenza pneumonia.

Associations between Short-Term Exposure to Ambient Air Pollution and Influenza: An Individual-Level Case-Crossover Study in Guangzhou, China

BACKGROUND

Influenza imposes a heavy burden on public health. Little is known, however, of the associations between detailed measures of exposure to ambient air pollution and influenza at an individual level.

OBJECTIVE

We examined individual-level associations between six criteria air pollutants and influenza using case-crossover design.

METHODS

In this individual-level time-stratified case-crossover study, we linked influenza cases collected by the Guangzhou Center for Disease Control and Prevention from 1 January 2013 to 31 December 2019 with individual residence-level exposure to particulate matter (PM 2.5 and PM 10 ), sulfur dioxide (SO 2 ), nitrogen dioxide (NO 2 ), ozone (O 3 ) and carbon monoxide (CO). The exposures were estimated for the day of onset of influenza symptoms (lag 0), 1-7 d before the onset (lags 1-7), as well as an 8-d moving average (lag07), using a random forest model and linked to study participants' home addresses. Conditional logistic regression was developed to investigate the associations between short-term exposure to air pollution and influenza, adjusting for mean temperature, relative humidity, public holidays, population mobility, and community influenza susceptibility.

RESULTS

N = 108,479 eligible cases were identified in our study. Every 10 - μ g / m 3 increase in exposure to PM 2.5 , PM 10 , NO 2 , and CO and every 5 - μ g / m 3 increase in SO 2 over 8-d moving average (lag07) was associated with higher risk of influenza with a relative risk (RR) of 1.028 (95% CI: 1.018, 1.038), 1.041 (95% CI: 1.032, 1.049), 1.169 (95% CI: 1.151, 1.188), 1.004 (95% CI: 1.003, 1.006), and 1.134 (95% CI: 1.107, 1.163), respectively. There was a negative association between O 3 and influenza with a RR of 0.878 (95% CI: 0.866, 0.890).

CONCLUSIONS

Our findings suggest that short-term exposure to air pollution, except for O 3 , is associated with greater risk for influenza. Further studies are necessary to decipher underlying mechanisms and design preventive interventions and policies. https://doi.org/10.1289/EHP12145.

High-Dose Influenza Vaccine Is Associated With Reduced Mortality Among Older Adults With Breakthrough Influenza Even When There Is Poor Vaccine-Strain Match

BACKGROUND

High-dose (HD) influenza vaccine offers improved protection from influenza virus infection among older adults compared with standard-dose (SD) vaccine. Here, we explored whether HD vaccine attenuates disease severity among older adults with breakthrough influenza.

METHODS

This was a retrospective cohort study of US claims data for influenza seasons 2016-2017, 2017-2018, and 2018-2019, defined as 1 October through 30 April, among adults aged ≥65 years. After adjusting the different cohorts for the probability of vaccination conditional on patients' characteristics, we compared 30-day mortality rate post-influenza among older adults who experienced breakthrough infection after receipt of HD or SD influenza vaccines and among those not vaccinated (NV).

RESULTS

We evaluated 44 456 influenza cases: 23 109 (52%) were unvaccinated, 15 037 (33.8%) received HD vaccine, and 6310 (14.2%) received SD vaccine. Significant reductions in mortality rates among breakthrough cases were observed across all 3 seasons for HD vs NV, ranging from 17% to 29% reductions. A significant mortality reduction of 25% was associated with SD vaccination vs NV in the 2016-2017 season when there was a good match between circulating influenza viruses and selected vaccine strains. When comparing HD vs SD cohorts, mortality reductions were higher among those who received HD in the last 2 seasons when mismatch between vaccine strains and circulating H3N2 viruses was documented, albeit not significant.

CONCLUSIONS

HD vaccination was associated with lower post-influenza mortality among older adults with breakthrough influenza, even during seasons when antigenically drifted H3N2 circulated. Improved understanding of the impact of different vaccines on attenuating disease severity is warranted when assessing vaccine policy recommendations.

The Effect of Rapid Point-of-Care Respiratory Pathogen Testing on Antibiotic Prescriptions in Acute Infections-A Systematic Review and Meta-analysis of Randomized Controlled Trials

Background

Rapid point-of-care testing for respiratory pathogens has gained increasing popularity, but its impact on antibiotic consumption is unclear. Thus, the aim of this systematic review and meta-analysis was to estimate the effect of rapid point-of-care testing on antibiotic prescriptions.

Methods

The search for this systematic review with meta-analysis was performed in February 2023. Randomized controlled trials investigating the impact of testing for respiratory pathogens in all-aged patients were included regardless of the comparator. The main outcome was the antibiotic prescription rate. Analyses were stratified by test type, test setting, and patient age. A random-effects Mantel-Haenszel model was used to calculate risk ratios with 95% confidence intervals. Risk of bias was assessed for included studies, and the quality of the evidence was rated according to GRADE.

Results

A total of 754 abstracts were screened, and 10 studies were included in the analysis. Risk of bias was high in 2, low in 4, and had some concerns in 4 studies. Four studies analyzed influenza and respiratory syncytial virus tests, and 6 studies analyzed multiplex (viral and/or bacterial) testing. The prescription rate was 48.2% (496/1029) in the influenza and respiratory syncytial virus test group and 48.7% (540/1109) in the control group (risk ratio [RR], 0.97; 95% CI, 0.92-1.02; moderate-quality evidence). The prescription rate in the multiplex testing group was 54.3% (1554/2859), and it was 57.3% (1336/2326) in the control group (RR, 1.00; 95% CI, 0.96-1.04; moderate-quality evidence). In an age-stratified analysis, the prescription rates showed no evidence of a difference (children: RR, 1.03; 95% CI, 0.81-1.30; adults: RR, 0.98; 95% CI, 0.96-1.01; very low- and moderate-quality evidence).

Conclusions

We found moderate-quality evidence that rapid point-of-care testing for respiratory pathogens does not decrease the antibiotic prescription rate.

[Respiratory infections: Additional transmission-based precautions in healthcare facilities]

INTRODUCTION

In health care, measures against cross-transmission of microorganisms are codified by standard precautions, and if necessary, they are supplemented by additional precautions.

STATE OF THE ART

Several factors impact transmission of microorganisms via the respiratory route: size and quantity of the emitted particles, environmental conditions, nature and pathogenicity of the microorganisms, and degree of host receptivity. While some microorganisms necessitate additional airborne or droplet precautions, others do not.

PROSPECTS

For most microorganisms, transmission patterns are well-understood and transmission-based precautions are well-established. For others, measures to prevent cross-transmission in healthcare facilities remain under discussion.

CONCLUSIONS

Standard precautions are essential to the prevention of microorganism transmission. Understanding of the modalities of microorganism transmission is essential to implementation of additional transmission-based precautions, particularly in view of opting for appropriate respiratory protection.

The burden of influenza and the role of influenza vaccination in adults aged 50-64 years: A summary of available evidence

Influenza is a vaccine-preventable disease and a global public health problem. Although most national influenza vaccination recommendations focus on subjects aged ≥65 years, an extensive burden of influenza has also been reported in those aged ≥50 years and is exacerbated by immune system aging. The main purpose of this review is to provide an overview of the burden of influenza and its potential prevention within the 50-64 age-group. These subjects account for a large proportion of the workforce, and play a central economic and social role. Individuals aged 50-64 years had a 3-times higher rate of hospitalization and a 9-fold higher mortality rate attributable to influenza than those aged 18-49-years, generating higher influenza-related hospitalization costs. Available data suggest that including healthy subjects aged 50-64 years in influenza vaccination recommendations would allow a broader population to be reached, reducing the economic and social burden of influenza.

Bacterial Co- or Superinfection in Patients Treated in Intensive Care Unit with COVID-19- and Influenza-Associated Pneumonia

Viral pneumonia is frequently complicated by bacterial co- or superinfection (c/s) with adverse effects on patients' outcomes. However, the incidence of c/s and its impact on the outcomes of patients might be dependent on the type of viral pneumonia. We performed a retrospective observational study in patients with confirmed COVID-19 pneumonia (CP) or influenza pneumonia (IP) from 01/2009 to 04/2022, investigating the incidence of c/s using a competing risk model and its impact on mortality in these patients in a tertiary referral center using multivariate logistic regressions. Co-infection was defined as pulmonary pathogenic bacteria confirmed in tracheal aspirate or bronchoalveolar lavage within 48 h after hospitalization. Superinfection was defined as pulmonary pathogenic bacteria detected in tracheal aspirate or bronchoalveolar lavage 48 h after hospitalization. We examined 114 patients with CP and 76 patients with IP. Pulmonary bacterial co-infection was detected in 15 (13.2%), and superinfection was detected in 50 (43.9%) of CP patients. A total of 5 (6.6%) co-infections (p = 0.2269) and 28 (36.8%) superinfections (p = 0.3687) were detected in IP patients. The overall incidence of c/s did not differ between CP and IP patients, and c/s was not an independent predictor for mortality in a study cohort with a high disease severity. We found a significantly higher probability of superinfection for patients with CP compared to patients with IP (p = 0.0017).

The Association between Influenza Vaccine and Risk of Chronic Kidney Disease/Dialysis in Patients with Hypertension

BACKGROUNDS

Influenza vaccination could decrease the risk of major cardiac events in patients with hypertension. However, the vaccine's effects on decreasing the risk of chronic kidney disease (CKD) development in such patients remain unclear.

METHODS

We retrospectively analysed the data of 37,117 patients with hypertension (≥55 years old) from the National Health Insurance Research Database during 1 January 2001 to 31 December 2012. After a 1:1 propensity score matching by the year of diagnosis, we divided the patients into vaccinated (n = 15,961) and unvaccinated groups (n = 21,156).

RESULTS

In vaccinated group, significantly higher prevalence of comorbidities such as diabetes, cerebrovascular disease, dyslipidemia, heart and liver disease were observed compared with unvaccinated group. After adjusting age, sex, comorbidities, medications (anti-hypertensive agents, metformin, aspirin and statin), level of urbanization and monthly incomes, significantly lower risk of CKD occurrence was observed among vaccinated patients in influenza season, non-influenza season and all season (Adjusted hazard ratio [aHR]: 0.39, 95% confidence level [C.I.]: 0.33-0.46; 0.38, 95% C.I.: 0.31-0.45; 0.38, 95% C.I.: 0.34-0.44, respectively). The risk of hemodialysis significantly decreased after vaccination (aHR: 0.40, 95% C.I.: 0.30-0.53; 0.42, 95% C.I.: 0.31-0.57; 0.41, 95% C.I.: 0.33-0.51, during influenza season, non-influenza season and all season). In sensitivity analysis, patients with different sex, elder and non-elder age, with or without comorbidities and with or without medications had significant decreased risk of CKD occurrence and underwent hemodialysis after vaccination. Moreover, the potential protective effect appeared to be dose-dependent.

CONCLUSIONS

Influenza vaccination decreases the risk of CKD among patients with hypertension and also decrease the risk of receiving renal replacement therapy. Its potential protective effects are dose-dependent and persist during both influenza and noninfluenza seasons.

Impact of different Agrobacterium rhizogenes strains on secondary metabolites accumulation in Nitraria schoberi L. hairy roots and antiviral activity of their extracts against influenza virus of subtypes A (H5N1) and A (H3N2)

To optimize protocol for obtaining hairy roots of Nitraria schoberi L. with high antiviral activities, factors such as four strain types of Agrobacterium rhizogenes (A4, ATCC15834, R-1601, 8196), two explant types, namely cotyledonous and primary leaves of seedlings, and different cultivation durations (30 and 90 d) were studied. The formation of hairy roots was observed after 2 to 4 wk of incubation, depending on the type of explant and the strain of A. rhizogenes used. The maximum transformation frequency (85.7%) was observed in the cotyledons genetically modified with the strain ATCC15834. The transgenic nature of hairy roots was revealed by PCR with primers to the Agrobacterium oncogenes rolB and rolC. The absence of contamination of the culture by A. rhizogenes was confirmed by primers to the virC and virD1 genes. Phytochemical analysis showed that accumulation of individual metabolites in the line samples exceeded their levels in the native Nitraria roots. Catechin content in the cultures of long-term cultivation (90 d) was found 1.4 to 2.2 times higher than the same samples of short cultivation (30 d) and 4.8 to 10.8 times higher in comparison with the native roots. The most productive in terms of catechin level were hairy roots of long-term cultivation obtained during the transformation of primary leaves of N. schoberi seedlings with ATCC15834 strain. These data were consistent with the highest antiviral activities against influenza viruses of A (H5N1) and A (H3N2) subtypes with neutralization indexes 6.5 to 6.75 log10, and selectivity index values were in the range 15.4 to 16.4.

Duration of influenza vaccine effectiveness in the elderly in Japan: A retrospective cohort study using large-scale population-based registry data

BACKGROUND

The immune response to influenza vaccination in the elderly is likely to be lower than that in young adults. Clinical protection may not persist year-round in the elderly. However, the effectiveness of influenza vaccine in the elderly has not been adequately studied, especially in terms of the duration of effectiveness.

METHODS

We used a linked database of healthcare administrative claims data and vaccination records maintained by the municipality of a city in Kanto region of Japan. We studied individuals who were aged 65 years or older at baseline and were followed up between April 1, 2014 to March 31, 2020. The duration of influenza vaccine effectiveness by age category was analyzed using a time-dependent piecewise Cox proportional hazard model with time-dependent vaccine status, prior season vaccination and covariates confirmed in the baseline period (age, sex, cancer, diabetes, chronic obstructive pulmonary diseases, asthma, chronic kidney diseases, and cardiovascular diseases).

RESULTS

We identified an analysis population of 83,146 individuals, of which 7,401 (8.9%) had experienced influenza and 270 (0.32%) underwent influenza-related hospitalization. Individuals who were vaccinated during the first season (n = 47,338) were older than non-vaccinated individuals (n = 35,808) (average age, 75.8 vs. 74.1 years, respectively). The multivariable analysis showed a lower incidence of influenza in vaccinated individuals (hazard ratio [HR], 0.47; 95% confidence interval [CI], 0.43-0.51; P < 0.001), while the incidence of hospitalization for influenza did not differ significantly by vaccination status (HR, 0.79; 95% CI, 0.53-1.18; P = 0.249). Protective effectiveness against incidence was maintained for 4 or 5 months after vaccination in those aged 65-69 and 80-years, 5 months in 70-79 years.

CONCLUSIONS

Our study identified moderate vaccine effectiveness in preventing the incidence of influenza in the Japanese elderly. Vaccine effectiveness showed a trend of gradual attenuation. Clinicians should suspect influenza infection even in those vaccinated, especially in elderly individuals who had received vaccination more than 4 or 5 months previously.

Cost-Effectiveness of Vaccination of Older Adults with an MF59®-Adjuvanted Quadrivalent Influenza Vaccine Compared to Standard-Dose and High-Dose Vaccines in Denmark, Norway, and Sweden

Individuals aged 65 years and above are at increased risk of complications and death from influenza compared with any other age group. Enhanced vaccines, as the MF59®-adjuvanted quadrivalent influenza vaccine (aQIV) and the high-dose quadrivalent influenza vaccine (HD-QIV), provide increased protection for older adults in comparison to the traditional standard-dose quadrivalent influenza vaccines (SD-QIV). This study aimed to assess the cost-effectiveness of aQIV compared to SD-QIV and HD-QIV in Denmark, Norway, and Sweden for adults aged ≥65 years. A static decision tree model was used to evaluate costs and outcomes of different vaccination strategies from healthcare payer and societal perspectives. This model projects that compared to SD-QIV, vaccination with aQIV could prevent a combined total of 18,772 symptomatic influenza infections, 925 hospitalizations, and 161 deaths in one influenza season across the three countries. From a healthcare payer perspective, the incremental costs per quality adjusted life year (QALY) gained with aQIV versus SD-QIV were EUR 10,170/QALY in Denmark, EUR 12,515/QALY in Norway, and EUR 9894/QALY in Sweden. The aQIV was cost saving compared with HD-QIV. This study found that introducing aQIV to the entire population aged ≥65 years may contribute to reducing the disease and economic burden associated with influenza in these countries.

Influenza Virus Infection Increases Host Susceptibility To Secondary Infection with Pseudomonas aeruginosa, and This Is Attributed To Neutrophil Dysfunction through Reduced Myeloperoxidase Activity

Secondary bacterial infection greatly increased the morbidity and mortality of influenza virus infection. To investigate the underlying mechanism by which influenza impairs the pulmonary defense against secondary Pseudomonas aeruginosa (P. aeruginosa) infection, we established a lethal mouse model in which to study secondary P. aeruginosa infection after influenza virus infection. We found a significant increase in host susceptibility to a secondary infection with P. aeruginosa in mice after an influenza virus infection, and this was accompanied by severe immunopathology and pulmonary inflammation. Importantly, we demonstrated that neutrophils were essential for P. aeruginosa clearance in secondarily infected mice. Further, we revealed that influenza impaired the phagocytosis and digestion functions of pulmonary neutrophils for P. aeruginosa clearance. We identified that the activity of reactive oxygen species (ROS) and the myeloperoxidase (MPO) activity of neutrophils in the lungs played an important role in antibacterial host defense in influenza-infected lungs. Hereby, influenza virus infection causes deficient MPO activity in neutrophils, and this contributes to the increased susceptibility to secondary P. aeruginosa infection. Treatment with Bacillus Calmette-Guerin polysaccharide nucleic acid (BCG-PSN) prior to secondary P. aeruginosa infection may improve the function of neutrophils, resulting in significantly reduced lethality during secondary P. aeruginosa infection. We also demonstrated that treatment with anti-influenza immune serum during the early stage of an influenza virus infection could decrease the disease severity of secondary P. aeruginosa infection. Our findings suggest that improving the MPO activity of neutrophils may provide a therapeutic strategy for viral-bacterial coinfection.

IMPORTANCE A secondary bacterial infection, such as that of P. aeruginosa, often occurs after a pulmonary virus infection and contributes to severe disease. However, the underlying mechanisms responsible for viral-bacterial synergy in the lung remain largely unknown. In this study, we reported that influenza virus infection increases a host’s susceptibility to secondary infection by P. aeruginosa by reducing the MPO activity of neutrophils. We also demonstrated that treatment with BCG-PSN or anti-influenza immune serum prior to secondary P. aeruginosa infection can reduce the disease severity. Our findings suggest that improving the MPO activity of neutrophils may provide a therapeutic strategy for viral-bacterial coinfection.

Deciphering Microbiota of Acute Upper Respiratory Infections: A Comparative Analysis of PCR and mNGS Methods for Lower Respiratory Trafficking Potential

Although it is clinically important for acute respiratory tract (co)infections to have a rapid and accurate diagnosis, it is critical that respiratory medicine understands the advantages of current laboratory methods. In this study, we tested nasopharyngeal samples (n = 29) with a commercially available PCR assay and compared the results with those of a hybridization-capture-based mNGS workflow. Detection criteria for positive PCR samples was Ct < 35 and for mNGS samples it was >40% target coverage, median depth of 1X and RPKM > 10. A high degree of concordance (98.33% PPA and 100% NPA) was recorded. However, mNGS yielded positively 29 additional microorganisms (23 bacteria, 4 viruses, and 2 fungi) beyond PCR. We then characterized the microorganisms of each method into three phenotypic categories using the IDbyDNA Explify^® Platform (Illumina^® Inc, San Diego, CA, USA) for consideration of infectivity and trafficking potential to the lower respiratory region. The findings are significant for providing a comprehensive yet clinically relevant microbiology profile of acute upper respiratory infection, especially important in immunocompromised or immunocompetent with comorbidity respiratory cases or where traditional syndromic approaches fail to identify pathogenicity. Accordingly, this technology can be used to supplement current syndrome-based tests, and data can quickly and effectively be phenotypically characterized for trafficking potential, clinical (co)infection, and comorbid consideration-with promise to reduce morbidity and mortality.

Therapeutic Targeting of Inflammation and Virus Simultaneously Ameliorates Influenza Pneumonia and Protects from Morbidity and Mortality

Influenza pneumonia is a severe complication caused by inflammation of the lungs following infection with seasonal and pandemic strains of influenza A virus (IAV), that can result in lung pathology, respiratory failure, and death. There is currently no treatment for severe disease and pneumonia caused by IAV. Antivirals are available but are only effective if treatment is initiated within 48 h of onset of symptoms. Influenza complications and mortality are often associated with high viral load and an excessive lung inflammatory cytokine response. Therefore, we simultaneously targeted the virus and inflammation. We used the antiviral oseltamivir and the anti-inflammatory drug etanercept to dampen TNF signaling after the onset of clinical signs to treat pneumonia in a mouse model of respiratory IAV infection. The combined treatment down-regulated the inflammatory cytokines TNF, IL-1β, IL-6, and IL-12p40, and the chemokines CCL2, CCL5, and CXCL10. Consequently, combined treatment with oseltamivir and a signal transducer and activator of transcription 3 (STAT3) inhibitor effectively reduced clinical disease and lung pathology. Combined treatment using etanercept or STAT3 inhibitor and oseltamivir dampened an overlapping set of cytokines. Thus, combined therapy targeting a specific cytokine or cytokine signaling pathway and an antiviral drug provide an effective treatment strategy for ameliorating IAV pneumonia. This approach might apply to treating pneumonia caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Associations of influenza and pneumococcal vaccinations with burdens of older family caregivers: The Japan Gerontological Evaluation study (JAGES) cross-sectional study

BACKGROUND

Influenza and pneumonia tend to be severe in older adults; thus, vaccination is necessary to prevent these illnesses. Vaccination is especially important for older family caregivers (OFCs) not only to prevent them from becoming ill, but also to prevent secondary infections in the family care receivers (FCRs), who are mostly frail older adults and have a higher risk of severe illness. Thus, we investigated whether caregiving burdens were associated with the vaccinations among older adults.

METHODS

We used cross-sectional data from the Japan Gerontological Evaluation Study (JAGES), which was conducted in 64 Japanese municipalities from November 2019 to January 2020. The target population consisted of 26,177 individuals aged 65 years or older who were independent and did not need public long-term care. The primary outcome was the uptakes of either or both influenza and pneumococcal vaccinations. Multinomial logistic regressions were performed, setting those who underwent neither vaccinations as the reference group.

RESULTS

Among the participants, 23.3 %, 25.8 %, 9.4 %, or 41.5 % underwent neither, only influenza, only pneumococcal, or the both vaccinations, respectively. The caregiving frequency, time length in a day, or dementia of FCR were negatively associated with influenza vaccination (caregiving almost every day: relative risk ratio {RRR}: 0.39, 95 % confident interval {95 % CI} [0.24-0.63]; caregiving almost all day: 0.44, 95 % CI: 0.23-0.85; caregiving for FCR: RRR:0.55, 95 % CI: 0.34-0.91). On the other hand, those caregiving burdens were not associated with pneumococcal only or the both vaccinations. Having a family physician mitigated all the negative effect of the caregiving burdens on the vaccinations.

CONCLUSION

Our results suggest that the caregiving burden is a barrier to influenza vaccination but not to pneumococcal vaccination and that having a physician mitigates the negative effect regardless of the burden kind.

Trivalent inactivated influenza vaccine response and immunogenicity assessment after one week and three months in repeatedly vaccinated adults

BACKGROUND

The influenza vaccine administrated every year is a recommended infection control procedure for individuals above the age of six months. However, the effectiveness of repeated annual vaccination is still an active research topic. Therefore, we investigated the vaccine immunogenicity in two independent groups: previously vaccinated versus non-vaccinated individuals at three time points; prior vaccination, one week and three months post vaccination. The assessment enabled us to evaluate the elicited immune responses and the durability of the induced protection in both groups.

RESEARCH DESIGN AND METHODS

A research study was conducted to assess the immunogenicity of a single dose of Trivalent Inactivated Influenza Vaccine (A/H1N1, A/H3N2, and B) in 278 healthy adults aged between 32 and 66 years. Almost half of the participants, 140 (50·36%), received influenza vaccination at least once precursor to past influenza seasons. One blood sample was taken prior to vaccination for complete blood analysis and baseline immunogenicity assessment. The selected study participants received a single vaccine dose on the first day, and then followed up for three months. Two blood samples were taken after one week and three months post vaccination, respectively, for vaccine immunogenicity assessment.

RESULTS

Before vaccination, the seroprotection, defined as a hemagglutination-inhibiting titer of =>1:40, was detected for the three vaccine virus strains in 20 previously vaccinated participants (14·29%) [8·95%, 21·2%]. We compared the overall vaccine response for the three virus strains using a normalized response score calculated from linearly transformed titer measurements; the score before vaccination was 84% higher in the previously vaccinated group and the mean difference between the two groups was statistically significant. Three months post-vaccination, we didn't find a significant difference in vaccine responses; the number of fully seroprotected individuals became 48 (34·29%) [26·48%, 42·77%] in the previously vaccinated group and 59 (42·75%) [34·37%, 51·45%] in the non-vaccinated group. The calculated response score was almost equal in both groups and the mean difference was no longer statistically significant.

CONCLUSION

Our findings suggest that a single dose of influenza vaccine is equally protective after three months for annually vaccinated adults and first-time vaccine receivers.

Cost-effectiveness of influenza vaccination with a high dose quadrivalent vaccine of the elderly population in Belgium, Finland, and Portugal

BACKGROUND

Seasonal influenza may result in severe outcomes, resulting in a significant increase of hospitalizations during the winter. To improve the protection provided by the standard dose influenza quadrivalent vaccine (SDQIV), a high-dose vaccine (HDQIV) has been developed specifically for adults aged 60 and older who are at higher risk of life-threatening complications.

OBJECTIVES

The aim of this study was to determine the cost-effectiveness of HD QIV vs. SD-QIV in the recommended population of three European countries: Belgium, Finland and Portugal.

METHODS

A cost-utility analysis comparing HDQIV vs. SDQIV was conducted using a decision tree estimating health outcomes conditional on influenza: cases, general practitioner and emergency department visits, hospitalizations and deaths. To account for the full benefit of the vaccine, an additional outcome-hospitalizations attributable to influenza-was also evaluated. Demographic, epidemiological and economic inputs were based on the respective local data. HDQIV relative vaccine efficacy vs. SDQIV was obtained from a phase IV efficacy randomized clinical trial. The incremental cost-effectiveness ratios (ICER) were computed for each country, and a probabilistic sensitivity analysis (1,000 simulations per country) was performed to assess the robustness of the results.

RESULTS

In the base case analysis, HDQIV resulted in improved health outcomes (visits, hospitalizations, and deaths) compared to SDQIV. The ICERs computed were 1,397, 9,581, and 15,267 €/QALY, whereas the PSA yielded 100, 100, and 84% of simulations being cost-effective at their respective willingness-to-pay thresholds, for Belgium, Finland, and Portugal, respectively.

CONCLUSION

In three European countries with different healthcare systems, HD-QIV would contribute to a significant improvement in the prevention of influenza health outcomes while being cost-effective.

PHEVIR: an artificial intelligence algorithm that predicts the molecular role of pathogens in complex human diseases

Infectious diseases are known to cause a wide variety of post-infection complications. However, it's been challenging to identify which diseases are most associated with a given pathogen infection. Using the recently developed LeMeDISCO approach that predicts comorbid diseases associated with a given set of putative mode of action (MOA) proteins and pathogen-human protein interactomes, we developed PHEVIR, an algorithm which predicts the corresponding human disease comorbidities of 312 viruses and 57 bacteria. These predictions provide an understanding of the molecular bases of complications and means of identifying appropriate drug targets to treat them. As an illustration of its power, PHEVIR is applied to identify putative driver pathogens and corresponding human MOA proteins for Type 2 diabetes, atherosclerosis, Alzheimer's disease, and inflammatory bowel disease. Additionally, we explore the origins of the oncogenicity/oncolyticity of certain pathogens and the relationship between heart disease and influenza. The full PHEVIR database is available at https://sites.gatech.edu/cssb/phevir/ .

Comparing antibiotic prescriptions in primary care between SARS-CoV-2 and influenza: a retrospective observational study

BACKGROUND

Antibiotics are frequently prescribed during viral respiratory infection episodes in primary care. There is limited information about antibiotic prescription during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic in primary care and its association with risk factors for an adverse course.

AIM

To compare the proportion of antibiotic prescriptions between patients with COVID-19 and influenza or influenza-like symptoms, and to assess the association between antibiotic prescriptions and risk factors for an adverse course of COVID-19.

DESIGN & SETTING

An observational cohort study using pseudonymised and coded routine healthcare data extracted from 85 primary care practices in the Netherlands.

METHOD

Adult patients with influenza and influenza-like symptoms were included from the 2017 influenza season to the 2020 season. Adult patients with suspected or confirmed COVID-19 were included from the first (15 February 2020-1 August 2020) and second (1 August 2020-1 January 2021) SARS-CoV-2 waves. Proportions of antibiotic prescriptions were calculated for influenza and COVID-19 patients. Odds ratios (ORs) were used to compare the associations of antibiotic prescriptions in COVID-19 patients with risk factors, hospital admission, intensive care unit (ICU) admission, and mortality.

RESULTS

The proportion of antibiotic prescriptions during the first SARS-CoV-2 wave was lower than during the 2020 influenza season (9.6% versus 20.7%), difference 11.1% (95% confidence interval [CI] = 8.7 to 13.5). During the second SARS-CoV-2 wave, antibiotic prescriptions were associated with being aged ≥70 years (OR 2.05; 95% CI = 1.43 to 2.93), the number of comorbidities (OR 1.46; 95% CI = 1.18 to 1.82), and admission to hospital (OR 3.19; 95% CI = 2.02 to 5.03) or ICU (OR 4.64; 95% CI = 2.02 to 10.62).

CONCLUSION

Antibiotic prescription was less common during the SARS-CoV-2 pandemic than during influenza seasons, and was associated with an adverse course and its risk factors. The findings suggest a relatively targeted prescription policy of antibiotics in primary care during COVID-19.

In-hospital incidence of and risk factors for influenza-associated respiratory failure

BACKGROUND

Respiratory failure (RF) is the most important complication of influenza virus infection. Its definition and incidence are heterogeneous in the literature.

METHODS

This systematic review and meta-analysis aim to determine the incidence of and risk factors for RF in patients hospitalized with influenza. Electronic databases were searched for articles on RF in patients hospitalized for influenza infection up to December 2021 regardless of their geographical location. Observational and experimental studies were considered for inclusion, excluding case series. The Newcastle-Ottawa and Johanna Briggs scales were used for quality assessment. A random-effects meta-analysis was performed, followed by subgroup analyses according to, among others, presence/absence of pneumonia, RF definition, serotype and time period. PRISMA guidelines were followed for this review.

RESULTS

Thirty-six studies were finally included in the meta-analysis. Overall, RF incidence was 24% (range 5%-85%, 95% confidence interval [95CI] 19%-31%). Significantly higher incidences of RF were found in patients with pneumonia (42%, 95CI 28%-57%, p = .006), when RF was defined as hypoxemia (58%, 95CI 31%-81%, p < .001), and during the 2009 pandemic (25%, 95CI 16%-36%) and postpandemic period (23%, 95CI 15%-34%, p = .01). No differences were found between human influenza serotypes. Assessment of risk factors associated with the development of RF was not possible due to their inconsistent and heterogeneous reporting.

CONCLUSION

Respiratory failure is frequent in hospitalized influenza patients, especially in patients with pneumonia and since the 2009 pandemic, although its definition and reporting widely vary in the literature. This complicates its characterization and comparison between cohorts and with other respiratory viruses.

Association of functional competencies with vaccination among older adults: a JAGES cross-sectional study

It is unknown whether higher functions in sublevels of competence other than instrumental activities of daily living (IADL) are associated with vaccinations. This study examined whether higher functions, including intellectual activity (IA) and social role (SR), were associated with vaccinations among 26,177 older adults. Older adults with incapable activities in IA and SR had increased risks for non-receipt of influenza vaccinations (IA: for one incapable task/activity: incident rate ratio (IRR) = 1.05, 95% confidence interval (CI) = 1.02-1.09; SR: for two incapable tasks: IRR = 1.12, 95% CI = 1.08-1.16). Those with incapable activities in IADL and IA had increased risks for non-receipt of pneumococcal vaccination (IADL: for two incapable tasks: IRR = 1.13, 95% CI = 1.05-1.23; IA: for two incapable tasks: IRR = 1.10, 95% CI = 1.08-1.12). Those with incapable activities in IADL, IA, and SR had increased risks for non-receipt of both of the two vaccinations (IADL: for two incapable tasks: IRR = 1.17, 95% CI = 1.03-1.33; IA: for two incapable tasks: IRR = 1.18, 95% CI = 1.11-1.25; SR: for two incapable tasks: IRR = 1.13, 95% CI = 1.07-1.20). Having a family physician mitigated associations for non-receipt, regardless of competency. Our results suggest-maintaining the higher functions are important for older adults to undergo recommended vaccinations as scheduled; also, having a family physician to promote vaccinations is beneficial even for older adults with limited functions.

Associations of influenza vaccination with severity of immune-related adverse events in patients with advanced thoracic cancers on immune checkpoint inhibitors

Background

Whether influenza vaccination (FV) is associated with the severity of immune-related adverse events (IRAEs) in patients with advanced thoracic cancer on immune checkpoint inhibitors (ICIs) is not fully understood.

Methods

Patients enrolled in this retrospective cohort study were identified from the Vanderbilt BioVU database and their medical records were reviewed. Patients with advanced thoracic cancer who received FV within 3 months prior to or during their ICI treatment period were enrolled in the FV-positive cohort and those who did not were enrolled in the FV-negative cohort. The primary objective was to detect whether FV is associated with decreased IRAE severity. The secondary objectives were to evaluate whether FV is associated with a decreased risk for grade 3-5 IRAEs and better survival times. Multivariable ordinal logistic regression was used for the primary analysis.

Results

A total of 142 and 105 patients were enrolled in the FV-positive and FV-negative cohorts, respectively. There was no statistically significant difference in patient demographics or cumulative incidences of IRAEs between the two cohorts. In the primary analysis, FV was inversely associated with the severity of IRAEs (OR 0.63; p=0.046). In the secondary analysis, FV was associated with a decreased risk for grade 3-5 IRAEs (OR 0.42; p=0.005). Multivariable Cox regression showed that FV was not associated with survival times.

Conclusions

Our study showed that FV does not increase toxicity for patients with advanced thoracic cancer on ICIs and is associated with a decreased risk for grade 3-5 IRAEs. No statistically significant survival differences were found between patients with and without FV.

Influenza vaccination and risk of atrial fibrillation in patients with gout: A nationwide population-based cohort study

Objective: Although influenza vaccination reduces the risk of atrial fibrillation (AF), its protective effect in patients with gout remains unclear. The present study aimed to evaluate the protective effect of influenza vaccination in patients with gout.

Methods: A total of 26,243 patients with gout, aged 55 and older, were enrolled from the National Health Insurance Research Database (NHIRD) between 1 January 2001, and 31 December 2012. The patients were divided into vaccinated (n = 13,201) and unvaccinated groups (n = 13,042). After adjusting comorbidities, medications, sociodemographic characteristics, the risk of AF during follow-up period was analyzed.

Results: In influenza, non-influenza seasons and all seasons, the risk of AF was significantly lower in vaccinated than in unvaccinated patients (Adjust hazard ratio [aHR]: 0.59, 95% confidence interval [CI]: 0.50–0.68; aHR: 0.50, 95% CI: 0.42–0.63; aHR: 0.55, 95% CI: 0.49–0.62, respectively). In addition, the risk of AF significantly decreased with increased influenza vaccination (aHR: 0.85, 95% CI: 0.69–1.04; aHR: 0.72, 95% CI: 0.60–0.87; aHR: 0.40, 95% CI: 0.33–0.49, after first, 2–3 times, and ≥4 times of vaccination, respectively). Furthermore, sensitivity analysis indicated that the risk of AF significantly decreased after influenza vaccination for patients with different sexes, medication histories, and comorbidities.

Conclusions: Influenza vaccination is associated with a lower risk of AF in patients with gout. This potentially protective effect seems to depend on the dose administered.

Independent effect of weather, air pollutants, and seasonal influenza on risk of tuberculosis hospitalization: An analysis of 22-year hospital admission data

BACKGROUND

While influenza infections and environmental factors have been documented as potential drivers of tuberculosis, no investigations have simultaneously examined their impact on tuberculosis at a population level. This study thereby made use of Hong Kong's surveillance data over 22 years to elucidate the temporal association between environmental influences, influenza infections, and tuberculosis activity.

METHODS

Weekly total numbers of hospital admissions due to tuberculosis, meteorological data, and outdoor air pollutant concentrations in Hong Kong during 1998-2019 were obtained. All-type influenza-like illness positive (ILI+) rate and type-specific ILI+ rates were used as proxies for influenza activity. Quasi-Poisson generalized additive models together with distributed lag non-linear models were used to assess the association of interest.

RESULTS

A total of 164,116 hospital admissions due to tuberculosis were notified in public settings over a period of 22 years. The cumulative adjusted relative risk (ARR) of hospital admission due to tuberculosis was 1.07 (95% CI, 1.00-1.14) when the mean ambient temperature increased from 15.1 °C (the 5th percentile) to 24.5 °C (median). Short-term exposure to air pollutants was not found to be statistically significantly related to tuberculosis hospitalization. Accounting for the environmental covariates in the analysis, the cumulative ARR of tuberculosis admission was elevated to 1.05 (95% CI, 1.01-1.08) when the rate of ILI+ total increased from zero to 19.9 per 1000 consultations, the 95th percentile.

CONCLUSION

Our findings demonstrated that increased influenza activity and higher temperature were related to a higher risk of tuberculosis admissions. Stepping up the promotion of influenza vaccination, especially before the summer season, may lower the risk of tuberculosis infection/reactivation for vulnerable groups (e.g. elderly born before the launch of Bacillus Calmette-Guérin vaccination programme).

Influenza virus causes lung immunopathology through down-regulating PPARγ activity in macrophages

Fatal influenza (flu) virus infection often activates excessive inflammatory signals, leading to multi-organ failure and death, also referred to as cytokine storm. PPARγ (Peroxisome proliferator-activated receptor gamma) agonists are well-known candidates for cytokine storm modulation. The present study identified that influenza infection reduced PPARγ expression and decreased PPARγ transcription activity in human alveolar macrophages (AMs) from different donors. Treatment with PPARγ agonist Troglitazone ameliorated virus-induced proinflammatory cytokine secretion but did not interfere with the IFN-induced antiviral pathway in human AMs. In contrast, PPARγ antagonist and knockdown of PPARγ in human AMs further enhanced virus-stimulated proinflammatory response. In a mouse model of influenza infection, flu virus dose-dependently reduced PPARγ transcriptional activity and decreased expression of PPARγ. Moreover, PPARγ agonist troglitazone significantly reduced high doses of influenza infection-induced lung pathology. In addition, flu infection reduced PPARγ expression in all mouse macrophages, including AMs, interstitial macrophages, and bone-marrow-derived macrophages but not in alveolar epithelial cells. Our results indicate that the influenza virus specifically targets the PPARγ pathway in macrophages to cause acute injury to the lung.

Influenza A, Influenza B, and SARS-CoV-2 Similarities and Differences – A Focus on Diagnosis

In late December 2019, the first cases of viral pneumonia caused by an unidentified pathogen were reported in China. Two years later, SARS-CoV-2 was responsible for almost 450 million cases, claiming more than 6 million lives. The COVID-19 pandemic strained the limits of healthcare systems all across the world. Identifying viral RNA through real-time reverse transcription-polymerase chain reaction remains the gold standard in diagnosing SARS-CoV-2 infection. However, equipment cost, availability, and the need for trained personnel limited testing capacity. Through an unprecedented research effort, new diagnostic techniques such as rapid diagnostic testing, isothermal amplification techniques, and next-generation sequencing were developed, enabling accurate and accessible diagnosis. Influenza viruses are responsible for seasonal outbreaks infecting up to a quarter of the human population worldwide. Influenza and SARS-CoV-2 present with flu-like symptoms, making the differential diagnosis challenging solely on clinical presentation. Healthcare systems are likely to be faced with overlapping SARS-CoV-2 and Influenza outbreaks. This review aims to present the similarities and differences of both infections while focusing on the diagnosis. We discuss the clinical presentation of Influenza and SARS-CoV-2 and techniques available for diagnosis. Furthermore, we summarize available data regarding the multiplex diagnostic assay of both viral infections.

Post-COVID-19 Infection With Meticillin-Sensitive Staphylococcus aureus (MSSA) Bacteremia, Discitis/Osteomyelitis, and Diffuse Abscesses: A Case Report

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), has been associated with a plethora of symptoms weeks after the acute infection. While many reports have investigated the novel syndrome of post-acute sequelae of COVID-19, fewer studies have examined post-COVID-19 secondary infections, which may be distinct from typical post-viral bacterial infections due to the multiorgan involvement of COVID-19. This case report aims to highlight a presentation in which a 65-year-old man had COVID-19 and subsequently developed methicillin-sensitive Staphylococcus aureus (MSSA) bacteremia with widespread seeding of secondary infections, including abscesses in the hand and paravertebral regions as well as discitis/osteomyelitis of the cervical spine. Further studies are needed to investigate whether an increased susceptibility to unusual secondary bacterial infections is present in post-COVID-19 patients.

Days of Flooding Associated with Increased Risk of Influenza

Influenza typically causes mild infection but can lead to severe outcomes for those with compromised lung health. Flooding, a seasonal problem in Iowa, can expose many Iowans to molds and allergens shown to alter lung inflammation, leading to asthma attacks and decreased viral clearance. Based on this, the hypothesis for this research was that there would be geographically specific positive associations in locations with flooding with influenza diagnosis. An ecological study was performed using influenza diagnoses and positive influenza polymerase chain reaction tests from a de-identified large private insurance database and Iowa State Hygienic Lab. After adjustment for multiple confounding factors, Poisson regression analysis resulted in a consistent 1% associated increase in influenza diagnoses per day above flood stage (95% confidence interval: 1.00–1.04). This relationship remained after removal of the 2009–2010 influenza pandemic year. There was no associated risk between flooding and influenza-like illness as a nonspecific diagnosis. Associated risks between flooding and increased influenza diagnoses were geographically specific, with the greatest risk in the most densely populated areas. This study indicates that populations who live, work, or volunteer in flooded environments should consider preventative measures to avoid environmental exposures to mitigate illness from influenza in the following year.

Voyich J. Examining the Executioners, Influenza Associated Secondary Bacterial Pneumonia

Influenza infections typically present mild to moderate morbidities in immunocompetent host and are often resolved within 14 days of infection onset. Death from influenza infection alone is uncommon; however, antecedent influenza infection often leads to an increased susceptibility to secondary bacterial pneumonia. Bacterial pneumonia following viral infection exhibits mortality rates greater than 10-fold of those of influenza alone. Furthermore, bacterial pneumonia has been identified as the major contributor to mortality during each of the previous four influenza pandemics. Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, and Streptococcus pyogenes are the most prevalent participants in this pathology. Of note, these lung pathogens are frequently found as commensals of the upper respiratory tract. Herein we describe influenza-induced host-changes that lead to increased susceptibility to bacterial pneumonia, review virulence strategies employed by the most prevalent secondary bacterial pneumonia species, and highlight recent findings of bacterial sensing and responding to the influenza infected environment.

The impact of clinical risk conditions on influenza and pneumonia diagnoses in England: a nationally representative retrospective cohort study, 2010-2019

The impact of influenza and pneumonia on individuals in clinical risk groups in England has not previously been well characterized. Using nationally representative linked databases (Clinical Practice Research Database (CPRD), Hospital Episode Statistics (HES) and Office for National Statistics (ONS)), we conducted a retrospective cohort study among adults (≥ 18 years) during the 2010/2011-2019/2020 influenza seasons to estimate the incidence of influenza- and pneumonia-diagnosed medical events (general practitioner (GP) diagnoses, hospitalisations and deaths), stratified by age and risk conditions. The study population included a seasonal average of 7.2 million individuals; approximately 32% had ≥1 risk condition, 42% of whom received seasonal influenza vaccines. Medical event incidence rates increased with age, with ~1% of adults aged ≥75 years hospitalized for influenza/pneumonia annually. Among individuals with vs. without risk conditions, GP diagnoses occurred 2-5-fold more frequently and hospitalisations were 7-10-fold more common. Among those with obesity, respiratory, kidney or cardiovascular disorders, hospitalisation were 5-40-fold more common than in individuals with no risk conditions. Though these findings likely underestimate the full burden of influenza, they emphasize the concentration of disease burden in specific age and risk groups and support existing recommendations for influenza vaccination.