Community-Acquired Pneumonia (CAP) is an acute infection of the pulmonary parenchyma accompanied by symptoms of acute illness and abnormal chest findings.
It is a lower respiratory tract infection acquired in the community within 24 hours to <2 weeks or occurring ≤48 hours of hospital admission in patients who do not meet the criteria for healthcare-associated pneumonia.
It occurs at the highest rates in the very young and the very old.
Potentially life-threatening especially in older adults and those with comorbid disease.


  • Pneumococcal and influenza vaccines are recommended for the prevention of community-acquired pneumonia (CAP)

Pneumococcal Vaccine1

  • There are 2 different types of pneumococcal vaccines: pneumococcal polysaccharide conjugate vaccine (PCV) and pneumococcal polysaccharide vaccine 23-valent (PPSV23)
  • Pneumococcal vaccination is routinely recommended for the following:
    • Persons ≥65 years old
    • Persons aged 19-64 years who smoke cigarettes, with chronic heart disease (including CHF and cardiomyopathy but excluding HPN), chronic lung disease (including chronic obstructive lung disease, asthma and emphysema), chronic liver disease (including liver cirrhosis), alcoholism and DM
    • People living in nursing homes or other long-term care facility
  • Immunocompromised conditions that require pneumococcal vaccination:
    • B- or T-lymphocyte deficiency, complement deficiencies and phagocytic disorders (excluding chronic granulomatous disease)
    • HIV infection (vaccine should be given as soon as possible)
    • Chronic renal failure and nephrotic syndrome
    • Leukemia, Hodgkin lymphoma, generalized malignancy and multiple myeloma
    • Organ transplant (solid)
    • Iatrogenic immunosuppression (including long-term systemic corticosteroid and radiation therapy)
      • Should be given at least 2 weeks before starting immunosuppressive therapy
    • Anatomical or functional asplenia (eg sickle cell disease and other hemoglobinopathies, congenital or acquired  asplenia, splenic dysfunction and splenectomy)
      • Should be given at least 2 weeks before an elective splenectomy
  • For ≥19 years old with cochlear implant and CSF leak, PCV13 should be given 1st then PPSV23 after 8 weeks
    • If the recent dose of PPSV23 is given ≤65 years old or ≥65 years old, another dose of PPSV23 must be given at least 8 weeks after the administration of PCV13 and at least 5 years after the most recent dose of PPSV23 
  • Pneumococcal 13-valent conjugate vaccine can be given to patients age >50 years to prevent pneumonia and other invasive pneumococcal diseases
  • Pneumococcal vaccine is not recommended for persons with history of serious allergic reaction to a vaccine component, moderate or severe acute illness, and pregnancy
  • Based on the recommendation made by the Advisory Committee on Immunization Practices (ACIP) of the Centers for Disease Control and Prevention (CDC), for patients >65 years w/ indications for both PCV13 and  PPSV23 vaccination with no history of any pneumococcal vaccination, PCV13 should be administered first, then followed by the PPSV23 dose 6-12 months subsequently
    • PCV13 & PPSV23 should not be administered concurrently in the same visit
    • If patient is PCV13-naive but with PPSV23 vaccination received at age 65 years or older, PCV13 should be given >1 year after the previous PPSV23 dose
    • For patients PCV13-naive but with PPSV23 vaccination/s received before age 65, PCV13 should be given >1 year after the most recent PPSV23 dose or as soon as possible if this window has passed, and at least 5 years after the most recent PPSV23 dose
    • If patient was previously vaccinated with PCV13 only before reaching 65 years of age and is now recommended for a PPSV23 dose, PPSV23 may be given 6-12 months after the PCV13 dose or as soon as possible if this window has passed
    • For patients with both PPSV23 and PCV13 doses given before age 65 years, PPSV23 may be given 6-12 months after the PCV13 dose or as soon as possible if this window has passed, and >5 years after the most recent PPSV23 dose
  • Revaccination of PPSV23 at age >65 years is recommended 5 years after the last dose of PPSV23 for persons who have received PPSV23 before age 65 years
    • 2nd dose of PPSV23 given 5 years after the 1st dose is advised in persons 19-64 years old with functional or anatomical asplenia and for persons who are immunocompromised

Influenza Vaccine1

  • Influenza vaccine is recommended for any person who is at increased risk for complications from influenza:
    • Persons >50 years old
    • Those w/ chronic illnesses [eg lung diseases, cardiovascular disease (CVD), diabetes mellitus (DM), renal dysfunction, hemoglobinopathies]
    • Immune system disorders [eg human immunodeficiency virus (HIV) infection, malignancies, use of immunosuppressive drugs, radiation therapy, organ or bone marrow transplantation]
    • Residents of nursing homes and other chronic care facilities
    • Healthcare workers and other persons (including household members) in close contact with persons at high-risk should be vaccinated to decrease the risk for transmitting influenza to persons at high-risk

1Recommendations for vaccination may vary between countries. Please refer to the local guidelines

Principles of Vaccine Administration

  • Both pneumococcal and influenza vaccines can be administered simultaneously at different sites without increasing side effects
  • No contraindication for use of either pneumococcal or influenza vaccine immediately after an episode of pneumonia

Smoking Cessation

  • Decreases the risk for pneumonia and other invasive pneumococcal diseases (IPD)
  • Lowers the risk of IPD by 14% each year after quitting smoking & will return to risk level similar to persons who had never smoked after 13 years

Management of Non-Responders

Treatment Failure

  • Generally defined as lack of response or worsening of clinical status
    • Hemodynamic instability
    • Impairment of respiratory function
    • Need for mechanical ventilation
    • Radiographic progression
    • Appearance of new metastatic infectious foci


  • Reassess patient for possible resistance to antibiotics being given
  • Consider presence of other pathogens (eg M tuberculosis, viruses, parasites or fungi)
  • In addition to microbiological diagnostic procedures, consider the following exam:
    • Chest computed tomography (CT) scan
    • Thoracentesis
    • Bronchoscopy with bronchoalveolar lavage (BAL) and transbronchial biopsies
    • Follow up chest X-ray to identify pneumothorax, cavitation and extension to previously uninvolved lobes, pulmonary edema and acute respiratory distress syndrome (ARDS)
  • Revise treatment accordingly

Follow Up

Low-risk Pneumonia

  • Most patients respond to treatment within 24-72 hours
  • Indicators of response to therapy:
    • Decline of fever within 72 hours & return of temperature to normal within 5 days
    • Resolution of respiratory signs

Patients with Poor Treatment Response

  • Do a follow-up chest X-ray
  • Reassess for possible resistance to antibiotics being given
  • Consider other pathogens (eg M tuberculosis, viruses, parasites or fungi)
  • Consider other conditions [eg pneumothorax, cavitation and extension to previously uninvolved lobes, pulmonary edema and acute respiratory distress syndrome (ARDS)]
  • Revise treatment accordingly

Moderate-risk and High-risk Pneumonia

  • Streamlining initial empiric broad-spectrum parenteral therapy to a single narrow-spectrum parenteral or oral
  • agent based on available lab data is recommended as early as 72 hours following initiation of empirical treatment
  • Indications for streamlining of antibiotic therapy:
    • Less cough and normalization of respiratory rate
    • Afebrile for >24 hours
    • Blood cultures are negative or etiology is not a high-risk (virulent/resistant) pathogen
    • No unstable comorbid condition or life-threatening complication [eg myocardial infarction (MI), congestive heart failure (CHF), complete heart block, new atrial fibrillation, supraventricular tachycardia]
    • No obvious reason for continued hospitalization [eg hypotension, acute mental changes, blood urea nitrogen (BUN):creatinine ratio of >10:1, hypoxemia, metabolic acidosis, etc]
    • Able to initiate & maintain oral intake
  • Switching therapy to an oral agent will allow discharge from the hospital as early as the 4th day of hospitalization & will lead to cost savings
  • Inpatient observation while receiving oral therapy is not necessary

Criteria for Discharge

  • Temperature of 36-37.5°C
  • Pulse <100 beats/minute
  • Respiratory rate (RR) 16-24 breaths/minute
  • Systolic blood pressure (SBP) >90 mmHg
  • Blood oxygen saturation >90%
  • Ability to eat & take oral antibiotics
  • Absence of active clinical or psychosocial problems requiring hospital stay
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