Browsing by Subject "Respiratory tract infections"

Now showing 1 - 5 of 5
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    Allergic Airway Disease in Mice Alters T and B Cell Responses during an Acute Respiratory Poxvirus Infection
    (Public Library of Science, 2013-04-19) Walline, Crystal C.; Sehra, Sarita; Fisher, Amanda J.; Guindon, Lynette M.; Kratzke, Ian M.; Montgomery, Jessica B.; Lipking, Kelsey P.; Glosson, Nicole L.; Benson, Heather L.; Sandusky, George E.; Wilkes, David S.; Brutkiewicz, Randy R.; Kaplan, Mark H.; Blum, Janice S.; Microbiology and Immunology, School of Medicine
    Pulmonary viral infections can exacerbate or trigger the development of allergic airway diseases via multiple mechanisms depending upon the infectious agent. Respiratory vaccinia virus transmission is well established, yet the effects of allergic airway disease on the host response to intra-pulmonary vaccinia virus infection remain poorly defined. As shown here BALB/c mice with preexisting airway disease infected with vaccinia virus developed more severe pulmonary inflammation, higher lung virus titers and greater weight loss compared with mice inoculated with virus alone. This enhanced viremia was observed despite increased pulmonary recruitment of CD8(+) T effectors, greater IFNγ production in the lung, and high serum levels of anti-viral antibodies. Notably, flow cytometric analyses of lung CD8(+) T cells revealed a shift in the hierarchy of immunodominant viral epitopes in virus inoculated mice with allergic airway disease compared to mice treated with virus only. Pulmonary IL-10 production by T cells and antigen presenting cells was detected following virus inoculation of animals and increased dramatically in allergic mice exposed to virus. IL-10 modulation of host responses to this respiratory virus infection was greatly influenced by the localized pulmonary microenvironment. Thus, blocking IL-10 signaling in virus-infected mice with allergic airway disease enhanced pulmonary CD4(+) T cell production of IFNγ and increased serum anti-viral IgG1 levels. In contrast, pulmonary IFNγ and virus-specific IgG1 levels were reduced in vaccinia virus-treated mice with IL-10 receptor blockade. These observations demonstrate that pre-existing allergic lung disease alters the quality and magnitude of immune responses to respiratory poxviruses through an IL-10-dependent mechanism.
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    Editorial: Change in epidemiology and etiology of respiratory tract and gastrointestinal infections during COVID-19 pandemic
    (Frontiers Media, 2024-08-15) Hoang, Van Thuan; Gautret, Philippe; Al-Tawfiq, Jaffar A.; Medicine, School of Medicine
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    Infants Admitted to US Intensive Care Units for RSV Infection During the 2022 Seasonal Peak
    (American Medical Association, 2023-08-01) Halasa, Natasha; Zambrano, Laura D.; Amarin, Justin Z.; Stewart, Laura S.; Newhams, Margaret M.; Levy, Emily R.; Shein, Steven L.; Carroll, Christopher L.; Fitzgerald, Julie C.; Michaels, Marian G.; Bline, Katherine; Cullimore, Melissa L.; Loftis, Laura; Montgomery, Vicki L.; Jeyapalan, Asumthia S.; Pannaraj, Pia S.; Schwarz, Adam J.; Cvijanovich, Natalie Z.; Zinter, Matt S.; Maddux, Aline B.; Bembea, Melania M.; Irby, Katherine; Zerr, Danielle M.; Kuebler, Joseph D.; Babbitt, Christopher J.; Glas Gaspers, Mary; Nofziger, Ryan A.; Kong, Michele; Coates, Bria M.; Schuster, Jennifer E.; Gertz, Shira J.; Mack, Elizabeth H.; White, Benjamin R.; Harvey, Helen; Hobbs, Charlotte V.; Dapul, Heda; Butler, Andrew D.; Bradford, Tamara T.; Rowan, Courtney M.; Wellnitz, Kari; Allen Staat, Mary; Aguiar, Cassyanne L.; Hymes, Saul R.; Randolph, Adrienne G.; Campbell, Angela P.; RSV-PIC Investigators; Pediatrics, School of Medicine
    Importance: Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections (LRTIs) and infant hospitalization worldwide. Objective: To evaluate the characteristics and outcomes of RSV-related critical illness in US infants during peak 2022 RSV transmission. Design, setting, and participants: This cross-sectional study used a public health prospective surveillance registry in 39 pediatric hospitals across 27 US states. Participants were infants admitted for 24 or more hours between October 17 and December 16, 2022, to a unit providing intensive care due to laboratory-confirmed RSV infection. Exposure: Respiratory syncytial virus. Main outcomes and measures: Data were captured on demographics, clinical characteristics, signs and symptoms, laboratory values, severity measures, and clinical outcomes, including receipt of noninvasive respiratory support, invasive mechanical ventilation, vasopressors or extracorporeal membrane oxygenation, and death. Mixed-effects multivariable log-binomial regression models were used to assess associations between intubation status and demographic factors, gestational age, and underlying conditions, including hospital as a random effect to account for between-site heterogeneity. Results: The first 15 to 20 consecutive eligible infants from each site were included for a target sample size of 600. Among the 600 infants, the median (IQR) age was 2.6 (1.4-6.0) months; 361 (60.2%) were male, 169 (28.9%) were born prematurely, and 487 (81.2%) had no underlying medical conditions. Primary reasons for admission included LRTI (594 infants [99.0%]) and apnea or bradycardia (77 infants [12.8%]). Overall, 143 infants (23.8%) received invasive mechanical ventilation (median [IQR], 6.0 [4.0-10.0] days). The highest level of respiratory support for nonintubated infants was high-flow nasal cannula (243 infants [40.5%]), followed by bilevel positive airway pressure (150 infants [25.0%]) and continuous positive airway pressure (52 infants [8.7%]). Infants younger than 3 months, those born prematurely (gestational age <37 weeks), or those publicly insured were at higher risk for intubation. Four infants (0.7%) received extracorporeal membrane oxygenation, and 2 died. The median (IQR) length of hospitalization for survivors was 5 (4-10) days. Conclusions and relevance: In this cross-sectional study, most US infants who required intensive care for RSV LRTIs were young, healthy, and born at term. These findings highlight the need for RSV preventive interventions targeting all infants to reduce the burden of severe RSV illness.
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    Predictors of pulmonary exacerbation treatment in cystic fibrosis
    (Elsevier, 2020-05) Sanders, Don B.; Ostrenga, Joshua S.; Rosenfeld, Margaret; Fink, Aliza K.; Schechter, Michael S.; Sawicki, Gregory S.; Flume, Patrick A.; Morgan, Wayne J.; Pediatrics, School of Medicine
    Background: Most studies of pulmonary exacerbations (PEx) in cystic fibrosis (CF) focus on intravenous (IV)-treated PEx, though most PEx are treated with oral antibiotics. Our objectives were to describe predictors of antibiotic choice and outcomes for PEx initially identified in clinic. Methods: For each patient in the U.S. CF Foundation Patient Registry, we selected the first PEx recorded at a clinic visit in 2013-14 following a clinic visit without a PEx. We used multivariable logistic regression to determine associations between clinical characteristics and antibiotic treatment choice. We determined outcomes in the 90 days after the first PEx. Results: Among 14,265 patients with a PEx initially identified in clinic, 21.4% received no antibiotics, 61.5% received new oral and/or inhaled antibiotics, and 17.0% had IV antibiotics within 14 days. Compared to IV antibiotics, patients more likely to receive new oral and/or inhaled antibiotics: were male, <13 years old, had BMI >10th percentile or 18.5 kg/m2, >90 days between clinic visits, FEV1 > 70% predicted at the PEx, no prior-year IV-treated PEx, FEV1 decline <10% predicted, and private insurance. Following the PEx, 30.3% of patients had no clinical encounters within 90 days. Treatment with IV antibiotics within 90 days occurred for 23.7% treated without antibiotics, 22.8% of new oral and/or inhaled antibiotics, and 27.1% of IV antibiotics. Conclusion: Most PEx identified in clinic are treated with new oral and/or inhaled antibiotics. Markers of disease severity are associated with antibiotic treatment choice. Many patients had no follow-up evaluation within 90 days of treatment.
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    Pulmonary Metagenomic Sequencing Suggests Missed Infections in Immunocompromised Children
    (Oxford University Press, 2019-05-17) Zinter, Matt S.; Dvorak, Christopher C.; Mayday, Madeline Y.; Iwanaga, Kensho; Ly, Ngoc P.; McGarry, Meghan E.; Church, Gwynne D.; Faricy, Lauren E.; Rowan, Courtney M.; Hume, Janet R.; Steiner, Marie E.; Crawford, Emily D.; Langelier, Charles; Kalantar, Katrina; Chow, Eric D.; Miller, Steve; Shimano, Kristen; Melton, Alexis; Yanik, Gregory A.; Sapru, Anil; DeRisi, Joseph L.; Pediatrics, School of Medicine
    BACKGROUND: Despite improved diagnostics, pulmonary pathogens in immunocompromised children frequently evade detection, leading to significant mortality. Therefore, we aimed to develop a highly sensitive metagenomic next-generation sequencing (mNGS) assay capable of evaluating the pulmonary microbiome and identifying diverse pathogens in the lungs of immunocompromised children. METHODS: We collected 41 lower respiratory specimens from 34 immunocompromised children undergoing evaluation for pulmonary disease at 3 children's hospitals from 2014-2016. Samples underwent mechanical homogenization, parallel RNA/DNA extraction, and metagenomic sequencing. Sequencing reads were aligned to the National Center for Biotechnology Information nucleotide reference database to determine taxonomic identities. Statistical outliers were determined based on abundance within each sample and relative to other samples in the cohort. RESULTS: We identified a rich cross-domain pulmonary microbiome that contained bacteria, fungi, RNA viruses, and DNA viruses in each patient. Potentially pathogenic bacteria were ubiquitous among samples but could be distinguished as possible causes of disease by parsing for outlier organisms. Samples with bacterial outliers had significantly depressed alpha-diversity (median, 0.61; interquartile range [IQR], 0.33-0.72 vs median, 0.96; IQR, 0.94-0.96; P < .001). Potential pathogens were detected in half of samples previously negative by clinical diagnostics, demonstrating increased sensitivity for missed pulmonary pathogens (P < .001). CONCLUSIONS: An optimized mNGS assay for pulmonary microbes demonstrates significant inoculation of the lower airways of immunocompromised children with diverse bacteria, fungi, and viruses. Potential pathogens can be identified based on absolute and relative abundance. Ongoing investigation is needed to determine the pathogenic significance of outlier microbes in the lungs of immunocompromised children with pulmonary disease.