Streptococcus pneumoniae

  • Diagnosis
  • Background
  • Lab Tests
  • References
  • Related Content

Indications for Testing

Laboratory Testing

  • CDC – testing recommendations
  • Initial testing – CBC, arterial blood gas, chemistry profile
  • Antigen-based testing
    • Immunochromatographic urinary antigen testing in symptomatic adults – 70-80% sensitivity, >90% specificity
      • Most sensitive with bacteremia
      • Prior antibiotic use does not affect antigen test
      • Urine antigen test may stay positive for up to one month; not useful for recurrences or for assessing therapy success
    • Caution – children may asymptomatically shed S. pneumoniae antigen in urine, decreasing clinical specificity of test
  • Culture
    • Gold standard – defined as isolation from blood or normally sterile site
    • Blood, cerebrospinal fluid (CSF), respiratory sources
  • Nucleic amplification tests and PCR – under investigation
  • Meningitis – Gram stain and CSF culture detect most cases of meningitis
  • Bacteremia and pneumonia
    • Blood cultures are positive in a minority of cases of invasive disease
    • High-quality sputum with gram stain and culture may yield results
  • Other testing for community-acquired pneumonia

Differential Diagnosis

Streptococcus pneumoniae causes pneumonia, otitis media, sinusitis, and meningitis.

Epidemiology

  • Incidence (CDC, 2015)
    • Invasive pneumococcal disease – 12,000 cases/year in U.S.
    • Meningitis – 3-6,000 cases/year in U.S.
    • Pneumonia – >400,000 hospitalization cases/year in U.S.
  • Transmission – humans are the natural reservoir for S. pneumoniae; organism colonizes in nasopharynx
    • Most common in winter and early spring

Organism

  • S. pneumoniae are gram-positive, typically lancet-shaped diplococci
  • More than 80 serotypes
  • S. pneumoniae serotypes that are pathogenic in humans are not always heavily encapsulated
    • Virulence determined by composition of capsular polysaccharide
    • Antibodies to capsular polysaccharides confer type-specific immunity

Risk for Invasive Disease

  • Asplenia
  • HIV infection
  • Alaska Native American Indian, African American
  • Immunocompromised disease states
  • <2 or ≥65 years
  • Chronic diseases (cardiac, pulmonary, liver, renal, DM)
  • Alcohol abuse
  • Smoking

Clinical Presentation

  • Pneumonia
    • 50% of community-acquired pneumonia cases are S. pneumoniae
      • Often develops as a secondary pneumonia during upper respiratory tract infections
      • Abrupt onset of fever, shaking chills, cough, dyspnea, tachypnea and fatigue
  • Otitis media (OM)
    • 30-50% of OM cases are S. pneumoniae
      • ~90% of children in U.S. have ≥1 episode by age 3
      • 50% have >6 episodes/year
      • Penicillin-resistant pneumococcus is the most common cause of recurrent or persistent OM
  • Sinusitis
    • Up to 40% of nonviral sinusitis cases are S. pneumoniae
  • Invasive disease
    • Meningitis
      • Neurologic sequelae common in survivors
    • Bacteremia in 25-40% of pneumonia
      • Causes 85% of all cases of bacteremia in pediatric population
      • Mortality rate for bacteremia is 20%; up to 60% in elderly
    • Endocarditis
    • Other – pericarditis, abdominal infections (eg, peritonitis), osteomyelitis, septic arthritis

Indications for Laboratory Testing

Tests generally appear in the order most useful for common clinical situations.
Click on number for test-specific information in the ARUP Laboratory Test Directory

Streptococcus pneumoniae Antigen, Urine 0060228
Method: Qualitative Immunochromatography

Limitations

False positives may occur because of cross-reactivity with other members of S. mitis group or asymptomatic colonization of S. pneumonia

Clinical correlation is recommended

Patients who have received the S. pneumoniae vaccines may test positive in the 48 hours following vaccination; avoid testing within 5 days of receiving vaccination

Streptococcus pneumoniae Antigen, CSF 0061162
Method: Qualitative Immunochromatography

Limitations

False positives may occur because of cross-reactivity with other members of S. mitis group

Clinical correlation is recommended

Patients who have received the S. pneumoniae vaccines may test positive in the 48 hours following vaccination; avoid testing within 5 days of receiving vaccination

Respiratory Culture and Gram Stain 0060122
Method: Stain/Culture/Identification

Blood Culture 0060102
Method: Continuous Monitoring Blood Culture/Identification

Limitations

Testing is limited to the University of Utah Health Sciences Center only

Cerebrospinal Fluid (CSF) Culture and Gram Stain 0060106
Method: Stain/Culture/Identification

Aerobic Organism Identification with Reflex to Susceptibility 0065070
Method: Identification. Methods may include biochemical, mass spectrometry, or sequencing.

Limitations

For suspected agents of bioterrorism, Salmonella or Shigella, notify your state department of health and refer isolates to your state laboratory for identification; susceptibilities on agents of bioterrorism are not performed at ARUP

Additional Tests Available

CBC with Platelet Count and Automated Differential 0040003
Method: Automated Cell Count/Differential

Renal Function Panel 0020144
Method: Quantitative Chemiluminescent Immunoassay/Quantitative Enzyme-Linked Immunosorbent Assay

Comments

Test for renal function

Panel includes albumin, calcium, carbon dioxide, creatinine, chloride, glucose, phosphorous, potassium, sodium, and BUN

Streptococcus pneumoniae Antibodies, IgG (14 Serotypes) 0050725
Method: Quantitative Multiplex Bead Assay

Comments

Quantify antibody levels to pneumococcal polysaccharides in persons receiving vaccine to determine response to vaccine and whether protective antibody levels are reached at 1 month post-immunization

Vaccination pre- and post-antibody titer may aid in diagnosis of patients with suspected antibody deficiency with chronic/recurrent sinopulmonary infections

Test not designed to determine protection against S. pneumoniae based on a single sample

Streptococcus pneumoniae Antibodies, IgG (9 Serotypes) 2008919
Method: Quantitative Multiplex Bead Assay

Comments

Quantify antibody levels to pneumococcal polysaccharides in persons receiving vaccine to determine response to vaccine and whether protective antibody levels are reached at 4 weeks post-immunization

Legionella pneumophila Antigen, Urine 0070322
Method: Qualitative Enzyme-Linked Immunosorbent Assay

Mycoplasma pneumoniae by PCR 0060256
Method: Qualitative Polymerase Chain Reaction

Chlamydia pneumoniae by PCR 0060715
Method: Qualitative Polymerase Chain Reaction

Comments

Confirm C. pneumoniae as infectious agent in nasal wash, nasopharyngeal aspirate, bronchoalveolar lavage (BAL) or pleural fluid

General References

Anjay M, Anoop P. Diagnostic utility of rapid immunochromatographic urine antigen testing in suspected pneumococcal infections. Arch Dis Child. 2008; 93(7): 628-31. PubMed

Avni T, Mansur N, Leibovici L, Paul M. PCR using blood for diagnosis of invasive pneumococcal disease: systematic review and meta-analysis. J Clin Microbiol. 2010; 48(2): 489-96. PubMed

Centers for Disease Control and Prevention (CDC). Streptococcus pneumoniae. CDC. [Accessed: Jan 2016]

Charles P. Early diagnosis of lower respiratory tract infections (point-of-care tests). Curr Opin Pulm Med. 2008; 14(3): 176-82. PubMed

Couturier M, Graf E, Griffin A. Urine antigen tests for the diagnosis of respiratory infections: legionellosis, histoplasmosis, pneumococcal pneumonia. Clin Lab Med. 2014; 34(2): 219-36. PubMed

Lynch J, Zhanel G. Streptococcus pneumoniae: epidemiology, risk factors, and strategies for prevention. Semin Respir Crit Care Med. 2009; 30(2): 189-209. PubMed

Madeddu G, Fois A, Pirina P, Mura M. Pneumococcal pneumonia: clinical features, diagnosis and management in HIV-infected and HIV noninfected patients. Curr Opin Pulm Med. 2009; 15(3): 236-42. PubMed

Niederman M. Community-acquired pneumonia: the U.S. perspective. Semin Respir Crit Care Med. 2009; 30(2): 179-88. PubMed

van der Poll T, Opal S. Pathogenesis, treatment, and prevention of pneumococcal pneumonia. Lancet. 2009; 374(9700): 1543-56. PubMed

References from the ARUP Institute for Clinical and Experimental Pathology®

Petti C, Woods C, Reller B. Streptococcus pneumoniae antigen test using positive blood culture bottles as an alternative method to diagnose pneumococcal bacteremia. J Clin Microbiol. 2005; 43(5): 2510-2. PubMed

Pickering J, Hill H. Measurement of antibodies to pneumococcal polysaccharides with Luminex xMAP microsphere-based liquid arrays. Methods Mol Biol. 2012; 808: 361-75. PubMed

Pickering J, Hoopes J, Groll M, Romero H, Wall D, Sant H, Astill M, Hill H. A 22-plex chemiluminescent microarray for pneumococcal antibodies. Am J Clin Pathol. 2007; 128(1): 23-31. PubMed

Pickering J, Martins T, Greer R, Schroder C, Astill M, Litwin C, Hildreth S, Hill H. A multiplexed fluorescent microsphere immunoassay for antibodies to pneumococcal capsular polysaccharides. Am J Clin Pathol. 2002; 117(4): 589-96. PubMed

Waddle E, Hanson K, Jhaveri R. Follow-up analysis of serious bacterial infections in children with fever without localising signs: how do the National Institute for Clinical Excellence guidelines perform with the emergence of non-vaccine pneumococcal serotypes? Arch Dis Child. 2009; 94(3): 247. PubMed

Medical Reviewers

Last Update: February 2016