scholarly journals Alternaria alternata Accelerates Loss of Alveolar Macrophages and Promotes Lethal Influenza A Infection

Viruses ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 946 ◽  
Author(s):  
Caroline M. Percopo ◽  
Michelle Ma ◽  
Eric Mai ◽  
Jamie L. Redes ◽  
Laura S. Kraemer ◽  
...  
Keyword(s):  
Virus Infection ◽  
Alveolar Macrophages ◽  
Alternaria Alternata ◽  
Influenza A ◽  
Influenza Infection ◽  
Concomitant Administration ◽  
Continuous Exposure ◽  
Susceptibility To Infection ◽  
Respiratory Virus Infection ◽  
Acute Respiratory Virus Infection

Chronic inhalation of fungi and fungal components has been linked to the development of respiratory disorders, although their role with respect to the pathogenesis of acute respiratory virus infection remains unclear. Here, we evaluate inflammatory pathology induced by repetitive administration of a filtrate of the ubiquitous fungus, Alternaria alternata, and its impact on susceptibility to infection with influenza A. We showed previously that A. alternata at the nasal mucosae resulted in increased susceptibility to an otherwise sublethal inoculum of influenza A in wild-type mice. Here we demonstrate that A. alternata-induced potentiation of influenza A infection was not dependent on fungal serine protease or ribonuclease activity. Repetitive challenge with A. alternata prior to virus infection resulted proinflammatory cytokines, neutrophil recruitment, and loss of alveolar macrophages to a degree that substantially exceeded that observed in response to influenza A infection alone. Concomitant administration of immunomodulatory Lactobacillus plantarum, a strategy shown previously to limit virus-induced inflammation in the airways, blocked the exaggerated lethal response. These observations promote an improved understanding of severe influenza infection with potential clinical relevance for individuals subjected to continuous exposure to molds and fungi.

scholarly journals Routine blood parameters are helpful for early identification of influenza infection in children

2020 ◽  
Author(s):  
Ronghe Zhu ◽  
Cuie Chen ◽  
Qiu Wang ◽  
Xixi Zhang ◽  
Chaosheng Lu ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Influenza A Virus ◽  
Early Identification ◽  
Influenza A ◽  
Influenza Infection ◽  
Influenza Virus Infection ◽  
Cutoff Value ◽  
Routine Blood ◽  
Influenza A Virus Infection

Abstract Purpose Routine blood parameters, such as the lymphocyte (LYM) count, platelet (PLT) count, lymphocyte-to-monocyte ratio (LMR), neutrophil-to-lymphocyte ratio (NLR), LYM*PLT and mean platelet volume-to-platelet ratio (MPV/PLT), are widely used to predict the prognosis of infectious diseases. We aimed to explore the value of these parameters in the early identification of influenza virus infection in children.Methods We conducted a single-center, retrospective, observational study of fever with influenza-like symptoms in pediatric outpatients from different age groups and evaluated the predictive value of various routine blood parameters measured within 48 hours of the onset of fever for influenza virus infection.Results The LYM count, PLT count, LMR and LYM*PLT were lower, and the NLR and MPV/PLT were higher in children with an influenza infection (PCR-confirmed and symptomatic). The LYM count, LMR and LYM*PLT in the influenza infection group were lower in the 1- to 6-year-old subgroup, and the LMR and LYM*PLT in the influenza infection group were lower in the >6-year-old subgroup. In the 1- to 6-year-old subgroup, the cutoff value of the LMR for predicting influenza A virus infection was 3.75, the sensitivity was 81.87%, the specificity was 84.31%, and the area under the curve (AUC) was 0.886; the cutoff value of the LMR for predicting influenza B virus infection was 3.71, the sensitivity was 73.58%, the specificity was 84.31%, and the AUC was 0.843. In the >6-year-old subgroup, the cutoff value of the LMR for predicting influenza A virus infection was 3.05, the sensitivity was 89.27%, the specificity was 89.61%, and the AUC was 0.949; the cutoff value of the LMR for predicting influenza B virus infection was 2.88, the sensitivity was 83.19%, the specificity was 92.21%, and the AUC was 0.924.Conclusions Routine blood tests are simple, inexpensive and easy to perform, and they are useful for the early identification of influenza virus infection in children. The LMR had the strongest predictive value for influenza virus infection in children older than 1 year, particularly influenza A virus infection.

scholarly journals Obesity Is Associated With Increased Susceptibility to Influenza A (H1N1pdm) but Not H3N2 Infection

2020 ◽  
Author(s):  
Hannah E Maier ◽  
Guillermina Kuan ◽  
Lionel Gresh ◽  
Roger Lopez ◽  
Nery Sanchez ◽  
...  
Keyword(s):  
Influenza A ◽  
Influenza Infection ◽  
High Risk Population ◽  
Virus Infections ◽  
Middle Aged ◽  
Symptomatic Infection ◽  
Logistic Regression Models ◽  
Susceptibility To Infection ◽  
Associated Symptoms ◽  
Increased Susceptibility

Abstract Background Obesity has been shown to increase the risk of severe outcomes and death for influenza virus infections. However, we do not understand the influence of obesity on susceptibility to infection or on nonsevere influenza outcomes. Methods We performed a case-ascertained, community-based study of influenza transmission within households in Nicaragua. To investigate whether obesity increases the likelihood of influenza infection and symptomatic infection we used logistic regression models. Results Between 2015 and 2018, a total of 335 index cases with influenza A and 1506 of their household contacts were enrolled. Obesity was associated with increased susceptibility to symptomatic H1N1pdm infection among adults (odds ratio [OR], 2.10; 95% confidence interval [CI], 1.08–4.06) but not children, and this association increased with age. Among adults with H1N1pdm infection, obesity was associated with increased likelihood of symptoms (OR, 3.91; 95% CI, 1.55–9.87). For middle-aged and older adults with obesity there was also a slight increase in susceptibility to any H1N1pdm infection (OR, 1.20; 95% CI, .62–2.34). Body mass index (BMI) was also linearly associated with increased susceptibility to symptomatic H1N1pdm infection, primarily among middle-aged and older women (5-unit BMI increase OR, 1.40; 95% CI, 1.00–1.97). Obesity was not associated with increased H3N2 susceptibility or associated symptoms. Conclusions We found that, among adults, obesity is associated with susceptibility to H1N1pdm infection and with symptoms associated with H1N1pdm infection, but not with susceptibility to H3N2 infection or associated symptoms. These findings will help target prevention efforts and therapeutics to this high-risk population.

scholarly journals Etiology and Clinical Outcomes of Acute Respiratory Virus Infection in Hospitalized Adults

2014 ◽  
Vol 46 (2) ◽  
pp. 67 ◽  
Author(s):  
Yu Bin Seo ◽  
Joon Young Song ◽  
Min Ju Choi ◽  
In Seon Kim ◽  
Tea Un Yang ◽  
...  
Keyword(s):  
Virus Infection ◽  
Clinical Outcomes ◽  
Respiratory Virus ◽  
Respiratory Virus Infection ◽  
Acute Respiratory Virus Infection

scholarly journals Association Between the Respiratory Microbiome and Susceptibility to Influenza Virus Infection

2019 ◽  
Vol 71 (5) ◽  
pp. 1195-1203 ◽  
Author(s):  
Tim K Tsang ◽  
Kyu Han Lee ◽  
Betsy Foxman ◽  
Angel Balmaseda ◽  
Lionel Gresh ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Influenza A ◽  
Influenza Infection ◽  
Influenza Virus Infection ◽  
Fold Increase ◽  
Transmission Model ◽  
Influenza B ◽  
Household Contacts ◽  
Index Cases

Abstract Background Previous studies suggest that the nose/throat microbiome may play an important role in shaping host immunity and modifying the risk of respiratory infection. Our aim is to quantify the association between the nose/throat microbiome and susceptibility to influenza virus infection. Methods In this household transmission study, index cases with confirmed influenza virus infection and their household contacts were followed for 9–12 days to identify secondary influenza infections. Respiratory swabs were collected at enrollment to identify and quantify bacterial species via high-performance sequencing. Data were analyzed by an individual hazard-based transmission model that was adjusted for age, vaccination, and household size. Results We recruited 115 index cases with influenza A(H3N2) or B infection and 436 household contacts. We estimated that a 10-fold increase in the abundance in Streptococcus spp. and Prevotella salivae was associated with 48% (95% credible interval [CrI], 9–69%) and 25% (95% CrI, 0.5–42%) lower susceptibility to influenza A(H3N2) infection, respectively. In contrast, for influenza B infection, a 10-fold increase in the abundance in Streptococcus vestibularis and Prevotella spp. was associated with 63% (95% CrI, 17–83%) lower and 83% (95% CrI, 15–210%) higher susceptibility, respectively. Conclusions Susceptibility to influenza infection is associated with the nose/throat microbiome at the time of exposure. The effects of oligotypes on susceptibility differ between influenza A(H3N2) and B viruses. Our results suggest that microbiome may be a useful predictor of susceptibility, with the implication that microbiome could be modulated to reduce influenza infection risk, should these associations be causal.

scholarly journals Proteome Alterations in Primary Human Alveolar Macrophages in Response to Influenza A Virus Infection

2012 ◽  
Vol 11 (8) ◽  
pp. 4091-4101 ◽  
Author(s):  
Lin Liu ◽  
Jianhong Zhou ◽  
Yimeng Wang ◽  
Robert J. Mason ◽  
Cornelius Joel Funk ◽  
...  
Keyword(s):  
Virus Infection ◽  
Influenza A Virus ◽  
Alveolar Macrophages ◽  
Influenza A ◽  
Human Alveolar Macrophages ◽  
Influenza A Virus Infection

scholarly journals Routine blood parameters are helpful for early identification of influenza infection in children

2020 ◽  
Author(s):  
Ronghe Zhu ◽  
Cuie Chen ◽  
Qiu Wang ◽  
Xixi Zhang ◽  
Chaosheng Lu ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Influenza A Virus ◽  
Early Identification ◽  
Influenza A ◽  
Influenza Infection ◽  
Influenza Virus Infection ◽  
Cutoff Value ◽  
Routine Blood ◽  
Influenza A Virus Infection

Abstract Purpose Routine blood parameters, such as the lymphocyte (LYM) count, platelet (PLT) count, lymphocyte-to-monocyte ratio (LMR), neutrophil-to-lymphocyte ratio (NLR), LYM*PLT and mean platelet volume-to-platelet ratio (MPV/PLT), are widely used to predict the prognosis of infectious diseases. We aimed to explore the value of these parameters in the early identification of influenza virus infection in children.Methods We conducted a single-center, retrospective, observational study of fever with influenza-like symptoms in pediatric outpatients from different age groups and evaluated the predictive value of various routine blood parameters measured within 48 hours of the onset of fever for influenza virus infection. Results The LYM count, PLT count, LMR and LYM*PLT were lower, and the NLR and MPV/PLT were higher in children with an influenza infection (PCR-confirmed and symptomatic). The LYM count, LMR and LYM*PLT in the influenza infection group were lower in the 1- to 6-year-old subgroup, and the LMR and LYM*PLT in the influenza infection group were lower in the >6-year-old subgroup. In the 1- to 6-year-old subgroup, the cutoff value of the LMR for predicting influenza A virus infection was 3.75, the sensitivity was 81.87%, the specificity was 84.31%, and the area under the curve (AUC) was 0.886; the cutoff value of the LMR for predicting influenza B virus infection was 3.71, the sensitivity was 73.58%, the specificity was 84.31%, and the AUC was 0.843. In the >6-year-old subgroup, the cutoff value of the LMR for predicting influenza A virus infection was 3.05, the sensitivity was 89.27%, the specificity was 89.61%, and the AUC was 0.949; the cutoff value of the LMR for predicting influenza B virus infection was 2.88, the sensitivity was 83.19%, the specificity was 92.21%, and the AUC was 0.924.Conclusions Routine blood tests are simple, inexpensive and easy to perform, and they are useful for the early identification of influenza virus infection in children. The LMR had the strongest predictive value for influenza virus infection in children older than 1 year, particularly influenza A virus infection.

scholarly journals A PAEDIATRIC DEATH DUE TO MENINGITIS-AN AUTOPSY DIAGNOSIS OF A RARE COMPLICATION OF INFLUENZA B INFECTION

2021 ◽  
Vol 9 (4) ◽  
pp. 590-595
Author(s):  
S. R Hulathduwa ◽  
N. Borukgama
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Influenza A ◽  
Rna Viruses ◽  
Rare Complication ◽  
Influenza Infection ◽  
Influenza B ◽  
Type B ◽  
B Virus ◽  
Autopsy Diagnosis

Influenza virus belongs to a group of single-stranded RNA viruses in the fam- ily Orthomyxoviridae.  They are subdivided into four types as A, B, C and D.  As Influenza B is considered a milder form of infection not known to be caus- ing pandemics compared to Influenza A, it is equally a less researched topic than Influenza A. However, few studies have shown that the mortality associ- ated with pediatric Influenza B infection is equal to or sometimes even greater than the mortality associated with Influenza A. Complications of Influenza A or B virus infection include pneumonia, myositis, myocarditis and encephali- tis/encephalopathy. Influenza-associated encephalitis/encephalopathy (IAE) is a rare complication of Influenza infection which is commoner following infec- tion with type A. This case elaborates a death of a three-year-old child due to meningoencephalitis following Influenza Type B infection.

scholarly journals Fibroblast growth factor-9 expression in airway epithelial cells amplifies the type I interferon response and alters influenza A virus pathogenesis

2021 ◽  
Author(s):  
Bradley Hiller ◽  
Yongjun Yin ◽  
Yi-Chieh Perng ◽  
Ítalo de Araujo Castro ◽  
Lindsey Fox ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Virus Infection ◽  
Airway Epithelium ◽  
Influenza A ◽  
Alveolar Epithelium ◽  
Airway Epithelial Cells ◽  
Type I ◽  
Airway Epithelial ◽  
Conducting Airway ◽  
Respiratory Virus Infection

Influenza A virus (IAV) preferentially infects conducting airway and alveolar epithelial cells in the lung. The outcome of these infections is impacted by the host response, including the production of various cytokines, chemokines, and growth factors. Fibroblast growth factor-9 (FGF9) is required for lung development, can display antiviral activity in vitro, and is upregulated in asymptomatic patients during early IAV infection. We therefore hypothesized that FGF9 would protect the lungs from respiratory virus infection and evaluated IAV pathogenesis in mice that overexpress FGF9 in club cells in the conducting airway epithelium (FGF9-OE mice). However, we found that FGF9-OE mice were highly susceptible to IAV and Sendai virus infection compared to control mice. FGF9-OE mice displayed elevated and persistent viral loads, increased expression of cytokines and chemokines, and increased numbers of infiltrating immune cells as early as 1 day post-infection (dpi). Gene expression analysis showed an elevated type I interferon (IFN) signature in the conducting airway epithelium and analysis of IAV tropism uncovered a dramatic shift in infection from the conducting airway epithelium to the alveolar epithelium in FGF9-OE lungs. These results demonstrate that FGF9 signaling primes the conducting airway epithelium to rapidly induce a localized, protective IFN and proinflammatory cytokine response during viral infection. Although this response protects the airway epithelial cells from IAV infection, it allows for early and enhanced infection of the alveolar epithelium, ultimately leading to increased morbidity and mortality. Our study illuminates a novel role for FGF9 in regulating respiratory virus infection and pathogenesis.

Influenza A-Associated In-Hospital Mortality in Very Older People: Does Inflammation Also Play a Role?

Gerontology ◽  
2021 ◽  
pp. 1-9
Author(s):  
Estibaliz Arrieta ◽  
Antonio Lalueza ◽  
Blanca Ayuso-García ◽  
Hernando Trujillo ◽  
Dolores Folgueira ◽  
...  
Keyword(s):  
Virus Infection ◽  
Hospital Mortality ◽  
Influenza A Virus ◽  
Influenza A ◽  
Influenza Infection ◽  
Oldest Old ◽  
Clinical Manifestations ◽  
Reactive Protein ◽  
Tertiary Teaching ◽  
Influenza A Virus Infection

<b><i>Background:</i></b> The aim of the study was to analyze the clinical manifestations and outcome of the oldest old (people aged ≥85 years) who were admitted to the hospital with a confirmed influenza A virus infection in comparison with younger patients and to assess the role of inflammation in the outcome of influenza infection in this population. <b><i>Methods:</i></b> This is an observational prospective study including all adult patients with influenza A virus infection hospitalized in a tertiary teaching hospital in Madrid, in 2 consecutive influenza seasons (2016–17 and 2017–18). <b><i>Results:</i></b> Five hundred nine hospitalized patients with influenza A infection were included, of whom 117 (23%) were older than 85 years (median age: 89.3 ± 3.2). We compared the clinical characteristics and outcome with those of the rest of the population (median age: 72.8 ± 15.7). Overall, mortality was higher in older patients (10% vs. 4%; <i>p</i> = 0.03) with no differences in clinical presentation. Patients older than 85 years who ultimately died (12 out of 117) showed increased systemic inflammation expressed by higher levels of C-reactive protein (CRP) and ferritin compared to survivors who were discharged (odds ratio [OR] of CRP &#x3e;20 mg/dL: 5.16, 95% confidence interval [CI]: 1.29–20.57, and OR of ferritin &#x3e;500 mg: 4.3, 95% CI: 1.04–17.35). <b><i>Conclusions:</i></b> Patients aged 85 and older with influenza A virus infection presented a higher in-hospital mortality than younger subjects. CRP and ferritin levels were higher in the oldest old who died, suggesting that inflammation could play a key role in the outcome of this subset of patients.

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