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Test ID: SPNC Streptococcus pneumoniae Antigen, Spinal Fluid

Reporting Name

Streptococcus pneumoniae Ag, CSF

Useful For

Rapid diagnosis of pneumococcal meningitis

Clinical Information

Streptococcus pneumoniae is the most frequently encountered bacterial agent of community-acquired pneumonia, and can also be an agent of bacterial meningitis. Because of the significant morbidity and mortality associated with pneumococcal pneumonia, septicemia, and meningitis, it is important to have diagnostic test methods available that can provide a rapid diagnosis. In instances where empirical antibiotics are being considered prior to culture confirmation, antigen testing may be useful.


A positive result supports a diagnosis of pneumococcal meningitis.


A negative result suggests that pneumococcal antigen is absent in the cerebrospinal fluid (CSF). However, infection due to Streptococcus pneumoniae cannot be ruled out since the antigen present in the specimen may be below the lower limit of detection of the test.


If pneumococcal meningitis is suspected, bacterial culture and Gram stain analysis on CSF should be performed.

Report Available

Same day/1 day

Day(s) Performed

Monday through Sunday

Clinical Reference

1. Plouffe JF, Moore SK, Davis R, Facklam RR: Serotypes of Streptococcus pneumoniae blood culture isolates from adults in Franklin County, Ohio. J Clin Microbiol. 1994 Jun;32(6):1606-1607

2. Johnston RB Jr: Pathogenesis of pneumonococcal pneumonia. Rev Infect Dis. 1991;13:509-517

3. Janoff EN, Musher DM: Streptococcus pneumoniae. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Elsevier; 2020:2473-2491

Method Name

Immunochromatographic Membrane Assay

Specimen Type


Additional Testing Requirements

According to the College of American Pathologists (CAP, IMM.41830), cerebrospinal fluid (CSF) samples collected to make an initial diagnosis and submitted for detection of Streptococcus pneumoniae antigen testing should also be submitted for routine bacterial culture. Mayo Clinic Laboratories recommends that CSF bacterial cultures be performed at the originating site.

Specimen Required

Container/Tube: Sterile vial

Specimen Volume: 1 mL

Collection Instructions: Submit specimen collected in vial 2, if possible. If not possible, note which vial from which the aliquot was obtained.

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
CSF Refrigerated (preferred) 14 days
  Frozen  14 days

Reference Values


Reference values apply to all ages.

Test Classification

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
SPNC Streptococcus pneumoniae Ag, CSF 20489-1


Result ID Test Result Name Result LOINC Value
31667 Streptococcus pneumoniae Ag, CSF 20489-1


If not ordering electronically, complete, print, and send Infectious Disease Serology Test Request (T916) with the specimen.

Mayo Clinic Laboratories | Microbiology and Infectious Disease Catalog Additional Information: