Pneumococcal Disease

Cause and key clinical manifestations of pneumococcal disease

Pneumococcal disease is caused by a bacterium Streptococcus pneumoniae, or pneumococcus. Pneumococcal disease includes several key clinical manifestations that can be noninvasive or invasive.1

The major clinical manifestations of pneumococcal disease in adults include1

  • Pneumonia
  • Bacteremia
  • Meningitis

S pneumoniae is the most common cause of community-acquired bacterial pneumonia.1

S pneumoniae can also cause illnesses of the upper respiratory tract, such as otitis media and sinusitis.1

Patients at increased risk for invasive pneumococcal disease (IPD)

Age increases the risk for IPD

  • There is approximately a 2-fold risk for IPD in healthy adults aged ≥65 years compared to healthy adults aged 50–64 years.2,a
  • Certain chronic conditions increase the risk for IPD in adults (18–64 years).2,a
Chronic condition Chronic heart disease Chronic lung disease Diabetes mellitus
Risk versus healthy adultsa ~3X ~7X ~3X
  1. aRetrospective cohort study using data from January 1, 2006, through December 31, 2010, from 3 health care claims databases representing >35 million insured adults ≥18 years of age. Risk for IPD was compared between healthy adults ≥65 years of age and healthy adults 50 to 64 years of age. Risk for IPD in adults with chronic conditions was compared to age-matched healthy counterparts.2

Chronic conditions that increase the risk for pneumococcal disease
  • Diabetes mellitus may cause patients to be in a hyperglycemic state, which can functionally impair certain immune cells. This leads to reduced clearance of bacteria and increases the probability of infection.3
  • Chronic heart disease may cause inadequate cardiac output that causes lung congestion. This in turn leads to reduced clearance of bacteria and may increase the risk for infection.4,5,6
  • Chronic lung disease (COPD) causes chronic lung inflammation and impaired functionality of certain cells of the immune system, which reduces clearance of bacteria and potentially leads to infection.7
Advanced age increases the risk for pneumococcal disease

There are many reasons why older patients are more susceptible to pneumococcal disease. For example, the cough mechanism becomes less effective, and the immune system weakens, increasing the susceptibility to pneumococcal disease.8

The burden of pneumococcal disease
  • Although noninvasive pneumococcal pneumonia is more prevalent than invasive disease, the diagnosis is often difficult to make, and confirming, for example, that a case of pneumonia is definitively caused by Streptococcus pneumoniae can be challenging.9
  • For this reason, invasive pneumococcal disease is a reliable indicator of overall pneumococcal disease burden.9

CDC Disease Information

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CDC=Centers for Disease Control and Prevention; COPD=chronic obstructive pulmonary disease.



  1. Centers for Disease Control and Prevention (CDC). Prevention of Pneumococcal Disease: Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep. 1997;46(RR-8): 1–24.


  1. Shea KM, Edelsberg J, Weycker D, et al. Rates of pneumococcal disease in adults with chronic medical conditions. Open Forum Infect Dis. 2014;1(1):1–9.


  1. Boyanova L, Mitov I. Antibiotic resistance rates in causative agents of infections in diabetic patients: rising concerns. Expert Rev Anti Infect Ther. 2013;11(4):411–420.


  1. Lung congestion. Encyclopædia Britannica. Accessed September 13, 2019.


  1. Ware LB, Matthay MA. Clinical practice. Acute pulmonary edema. N Engl J Med. 2005;353(26):2788–2796.


  1. Mor A, Thomsen RW, Ulrichsen SP, et al. Chronic heart failure and risk of hospitalization with pneumonia: a population-based study. Eur J Intern Med. 2013;24(4):349–353.


  1. Barnes PJ. Cellular and molecular mechanisms of chronic obstructive pulmonary disease. Clin Chest Med. 2014;35(1):71–86.


  1. Weiskopf D, Weinberger B, Grubeck-Loebenstein B. The aging of the immune system. Transpl Int. 2009;22(11):1041–1050.


  1. World Health Organization (WHO). 23-valent pneumococcal polysaccharide vaccine. WHO position paper. Wkly Epidemiol Rec. 2008;83(42):373–384. Accessed September 13, 2019.

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US-PNX-00574 11/19