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respiratory tract infection

Includes: 1) upper respiratory tract infection 2) lower respiratory tract infection Pathology: - when air is forced over moist respiratory mucosa, it will generate more virus-laden respiratory particles - symptomatic patients are more likely to have active infection, more likely to have a large burden of virus, & more likely to be spreading virus into the surrounding air because they are coughing, sneezing, or breathing heavily - respiratory emissions are densest closest to their source - in poorly ventilated spaces, virus-laden aerosols can accumulate, leading to higher inocula & greater risk for infection even if distanced from source - a longer time of exposure to virus-laden aerosols, increases probability of infection [7] Clinical manifestations: - in older adults viral respiratory tract infections may present with nonspecific symptoms such as worsening fatigue Laboratory: - in older adults with viral respiratory tract infections, complete blood count, comprehensive metabolic panel & urinalysis may be normal - Respiratory virus antigen* - Respiratory virus DNA+RNA* * Loincs listed for 'Respiratory virus'; indication(s) unclear Radiology: - in older adults with viral respiratory tract infections, chest X-ray is generally normal Complications: - children's medical visits for respiratory tract infection (within 3 days) confer 12-fold increase in risk for ischemic stroke [2]* * Editorialist not impressed. Absolute risk is very low, No evidence that attempt to treat would mitigate risk. [2] Management: - delayed antibiotic prescription for outpatients is not associated with adverse outcomes [1] - fewer antibiotic prescriptions associated with a small increase in cases of pneumonia, but not mastoiditis, empyema, meningitis, intracranial abscess, or Lemierre syndrome [3] - association with peritonsillar abscess less clear [3] - penicillin or amoxicillin as effective & associated with fewer adverse events than amoxicillin clavulanate or cephalosporins for treatment of acute respiratory tract infections (otitis media, group A streptococcal pharyngitis, or sinusitis) in children [5] Comparative biology: - intranasal application of an ointment containing neomycin prevented aerosol transmission of respiratory viruses [8] - intranasal neomycin induces expression of multiple interferon-stimulated genes important in containing viral infections - this occurs independent of anti-bacterial effects of neomycin [8] - in mice, activation of these genes has dose-dependent benefits for prevention & treatment of multiple variants of SARS-CoV2 & influenza A viruses [8] - intranasal neomycin ointment (Neosporin) in healthy humans induces expression of multiple interferon-stimulated genes [8] Notes: - 11% of patients with acute respiratory tract infections receive systemic glucocorticoids* [6] * it is not known how many of these prescriptions may have been appropriate

Related

aerosol respiratory system

Specific

COVID-19 influenza lower respiratory tract infection (LRI) respiratory syncytial virus (RSV) upper respiratory tract infection (URI, common cold)

General

infection (infectious disease) respiratory tract disease

References

  1. Little P et al Delayed antibiotic prescribing strategies for respiratory tract infections in primary care: pragmatic, factorial, randomised controlled trial. BMJ 2014;348:g1606 PMID: 24603565 http://www.bmj.com/content/348/bmj.g1606
  2. Hills NK et al Timing and number of minor infections as risk factors for childhood arterial ischemic stroke. Neurology. August 20, 2014 PMID: 25142897 http://www.neurology.org/content/early/2014/08/20/WNL.0000000000000752 - Marquardt L A common cold is no stroke of luck. Risk for cerebral ischemia in Children. Neurology. August 20, 2014 PMID: 25142898 http://www.neurology.org/content/suppl/2014/08/20/WNL.0000000000000752.DC1/WNL.0000000000000760.pdf
  3. Gulliford MC, Moore MV, Little P et al Safety of reduced antibiotic prescribing for self limiting respiratory tract infections in primary care: cohort study using electronic health records. BMJ 2016;354:i3410 PMID: 27378578 - Del Mar C. Antibiotics for acute respiratory tract infections in primary care: Fresh reassurance that reducing prescribing is safe. BMJ 2016 Jul 5; 354:i3482 PMID: 27381415
  4. Loinc
  5. Gerber JS, Ross RK, Bryan M et al Association of Broad- vs Narrow-Spectrum Antibiotics With Treatment Failure, Adverse Events, and Quality of Life in Children With Acute Respiratory Tract Infections. JAMA. 2017;318(23):2325-2336 PMID: 29260224 https://jamanetwork.com/journals/jama/article-abstract/2666503
  6. Dvorin EL, Lamb MC, Monlezun DJ et al. High frequency of systemic corticosteroid use for acute respiratory tract illnesses in ambulatory settings. JAMA Intern Med 2018 Feb 26 PMID: 29482204
  7. Klompas M, Baker M, Rhee C What Is an Aerosol-Generating Procedure? JAMA Surg 2020. Dec 15 PMID: 33320188 https://jamanetwork.com/journals/jamasurgery/fullarticle/10.1001/jamasurg.2020.6643
  8. Mao T, Kim J, Pena-Hernandez MA et al. Intranasal neomycin evokes broad-spectrum antiviral immunity in the upper respiratory tract. Proc Natl Acad Sci U S A 2024 Apr 30; 121:e2319566121. PMID: 38648490 PMCID: PMC11067057 Free PMC article https://www.pnas.org/doi/10.1073/pnas.2319566121