CPA, RSV, Flu, COVID

• Other Respiratory Disorders

  • CAP
  • RSV
  • Flu
  • COVID-19
• Community Acquired Pneumonia (CAP) is the leading cause of death from an infectious disease and the 6th leading cause of death, with 45,000 deaths in the US yearly and highest incidence in the winter months
• CAP in adults

  • Viruses including influenza are a common cause
  • Bacterial infections, with Streptococcus pneumoniae being the most common
  • Other bacterial causes include Haemophilus influenzae, Staph Aureus, Mycoplasma pneumoniae, Chlamydia pneumoniae, Legionella pneumophila
• CAP in young adults and older children

  • Mycoplasma pneumoniae is the most common cause
  • Viruses are also a common cause
  • Chlamydia pneumoniae (not the same as chlamydial pneumonia in newborns)
• CAP in children and infants


  • Viral agents are the most common cause, including RSV, adenovirus, parainfluenza, influenza A and B
  • Bacterial causes include Streptococcus pneumoniae and Haemophilus influenzae
• Risk factors for CAP

  • Neonates (Group B strep)
  • Very young or very old
  • Other viral infections
  • Cigarette smoking
  • Chronic diseases
  • Alcoholism
  • Institutionalization
  • Poor cough effort
  • GERD
  • Immunosuppression
• Symptoms of CAP

  • Cough
  • Fever
  • Tachypnea, tachycardia
  • Malaise/fatigue
  • Sudden chills
  • Chest pain
  • Sputum production
  • Decreased breath sounds
  • Consolidation on percussion
  • Egophony
  • Bronchophony
  • Whispered pectoriloquy
  • Tactile fremitus
• Specific findings in CAP

  • Pneumococcal: rust colored sputum, GI symptoms, myalgias
  • Mycoplasma pneumoniae: < 35, malaise, sore throat, dry cough, maculopapular rash (10-20% of time)
  • Klebsiella pneumoniae: Upper lobe, currant jelly sputum, tissue necrosis, mortality rate 25-50%
  • Haemophilus influenzae: younger group if not vaccinated, coryza as prodrome, underlying lung disease in adults
  • Legionella pneumophila: middle-aged men, smokers, alcohol abusers, immunosuppressed, prodrome with flu like symptoms, neurological manifestations, mucoid sputum, relative bradycardia
  • Chlamydial: not seriously ill
  • Viral: headache, fever, myalgia, cough with mucopurulent sputum, milder symptoms than bacterial
• CURB-65 Score

  Confusion<|>Urea > 7 mmol/L (BUN > 19 mg/dL)<|>Respiratory rate > 30/min<|>Systolic blood pressure < 90 mm OR Diastolic blood pressure < 60 mm Hg<|>Age > 65 years of age
• CURB-65 Score Interpretation

  • CURB > 4: ICU management (27.8% 30-day mortality)
  • CURB = 3: Hospital admission (consider ICU) (14% 30-day mortality)
  • CURB = 2: Hospital admission or outpatient management with very close follow-up (6.8% 30-day mortality)
  • CURB = 0 - 1: Outpatient management (2.7% 30-day mortality)
• IDSA/ATS Criteria for Defining Severe Pneumonia

  • One major or three minor criterion suggests severe pneumonia

  Minor: RR > 30 breaths/min; Multilobar infiltrates; Confusion or disorientation; BUN > 20 mg/dL; WBC < 4000 cells; Thrombocytopenia < 100,000; Hypothermia < 36 degrees C; Hypotension requiring aggressive fluid resuscitation

  Major: septic shock, Respiratory failure requiring mechanical ventilation
• Metamyelocyte

  Crescent-shaped nucleus
• Myelocyte

  Round nucleus, small number of granules
• Degenerative Left Shift

  When available and more mature neutrophils forms are exhausted, less mature forms are accessed, and the total number of WBCs begin to fall
• CAP Outpatient Diagnosis

  1. All patients suspected of pneumonia need to have a chest x-ray to confirm or establish the diagnosis

  2. 2019 New Guideline: Sputum gram stain only in those with severe disease or those with suspected MRSA or Pseudomonas aeruginosa

  3. CBC, BUN should be obtained with other labs dictated by comorbidities
• Four potential causes of a false negative chest x-ray for CAP: early disease (delay up to 10 days), dehydration, neutropenia, and Pneumocystis Carinii (10-40% of patients have a normal x-ray)
• Additional CAP Diagnostics

  1. Pretreatment blood cultures for those with severe disease managed inpatient and those inpatients with suspected MRSA or P. aeruginosa

  2. Procalcitonin: not addressed in guideline

  3. Pretreatment urinary antigens for Legionella and Mycoplasma are NOT recommended

  4. Obtain influenza cultures if influenza circulating
• IDSA/ATS CAP Outpatient Treatment

  1. For healthy outpatient adults without comorbidities or risk factors for antibiotic resistant pathogens: Amoxicillin, Doxycycline, or a Macrolide (in areas with pneumococcal resistance to macrolides <25%)

  2. For outpatient adults with comorbidities: Combination therapy with Amoxicillin/clavulanate or a cephalosporin plus a Macrolide or Doxycycline, or Monotherapy with a Respiratory fluoroquinolone
• Recent therapy or a repeated course of therapy with beta-lactams, macrolides, or fluoroquinolones are risk factors for pneumococcal resistance to the same class of antibiotic, so an antimicrobial agent from an alternative class is preferred
• Duration of CAP Outpatient Antibiotic Treatment

  1. Minimum of 5 days

  2. Patient should be afebrile and clinically stable for 48 – 72 hours prior to discontinuation of antibiotics
• Corticosteroids are not recommended for use outpatient with pneumonia, but may be considered in patients with septic shock
• Follow-up chest imaging is not recommended for CAP patients, but patients eligible for lung cancer screening should have it performed
• Annually in the USA, 4-5 million children younger than 4 years acquire an RSV infection, and RSV is responsible for 177,000 hospitalizations and 4,000 deaths in adults ages ≥65 years
• Model of RSV infection

  Virion penetrates select respiratory tract cells in airways, leading to epithelial cell sloughing, impaired ciliary action, and edema, resulting in airway obstruction, often worse in exhalation
• Reason why immunity to RSV does not last

  Limited immunologic response due to the virus largely replicating in the airways (not systemically), resulting in signs and symptoms fairly limited to the respiratory tract with a low rate of fever, body aches, etc.
• Clinical manifestations of RSV

  • In infants, particularly <3 months: Bronchiolitis, Pneumonia, Tracheobronchitis, Acute otitis media

  In older adults: Pneumonia, COPD exacerbation, Heart failure exacerbation
• Risk factors for acquiring RSV disease in younger children

  • Childcare attendance
  • Older siblings in preschool or school
  • Crowding and lower socioeconomic status
  • Exposure to environmental pollutants (2nd hand smoke)
  • Multiple birth sets (especially triplets or greater)
  • No or limited breastfeeding
• Risk factors for severe RSV disease and hospitalization

  • Prematurity, especially ≤29 weeks gestation
  • Age younger than 3 months at time of infection
  • Chronic lung disease, including asthma
  • Congenital heart disease
  • Severe combined immunodeficiency (SCID)
  • Severe neuromuscular disease
• The majority of RSV disease admissions is in otherwise well full-term infants
• RSV in otherwise healthy children >3 months


  • Significant coughing and wheezing but child otherwise appears only mildly ill
  • Cough/wheeze usually lasts 2-3 weeks
  • Cessation of cough/wheeze corresponds with return on ciliary function
• RSV in otherwise healthy children <3 months

  • Clinical presentation may be atypical, with irritability, decreased activity including feeding, and periods of apnea
  • May require hospitalization
• Clinical presentation associated with risk for severe RSV disease and hospitalization

  • Toxic appearance at time of presentation
  • Respiratory rate higher than 70 breaths/min on room air
  • Atelectasis or pneumonitis on chest radiography
  • Oxygen saturation lower than 95% on room air
  • Periods of apnea
• Reasons for RSV testing

  Therapeutic decision making, especially to avoid unneeded antibiotic therapy

  Rule in/out COVID-19, influenza, where select antiviral therapy available

  Isolation of patients

  Parent/caregiver/staff education
• Palivizumab (Synagis®)

  Monoclonal antibody produced by recombinant DNA

  Used for RSV prevention in infants/children at high risk for severe RSV disease, noted to reduce RSV disease hospitalization rate by up to 55%

  Provides passive immunity against RSV, but plays no role in treatment of acute RSV

  Is not FDA-approved for use in adults at high risk for severe RSV disease
• Eligibility for Palivizumab (Synagis®)

  • Preterm infants age <1 year (chronologically) at start of RSV season, especially with chronic lung disease

  In second year of life, for children who continue to require medical intervention (supplemental oxygen, chronic corticosteroid or diuretic therapy)

  Age <24 months with hemodynamically significant congenital heart disease requiring medications for heart failure or will need transplant or infants with pulmonary HTN
• Factors associated with severe RSV illness in older adults

  • Age ≥65 years or older

  Chronic heart or lung disease, with heart failure being a particular risk

  COPD

  Asthma

  Immunosuppressive disease
• RSV Vaccination

  Currently >50 RSV vaccines in preclinical and clinical trials, with likely one vaccine to be approved in 2023

  Models include immunizing during pregnancy to provide passive immunity to infants, and direct immunization of at-risk adults, especially those age ≥60 years
• Commonly used therapies in outpatient RSV, such as inhaled and/or systemic corticosteroids and beta2-agonists, have little evidence of efficacy without underlying airway disease, and currently-available antivirals and antimicrobial therapy have little evidence of efficacy in all with RSV disease
• Maternal vitamin D supplementation during pregnancy and breastfeeding appear to provide a degree of infant protection from severe RSV
• Influenza is a highly contagious respiratory illness caused by influenza viruses