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HelpTest Code SPNEU Streptococcus pneumoniae Antigen, Random, Urine
Reporting Name
Streptococcus pneumoniae Ag, UUseful For
Rapid diagnosis of pneumococcal pneumonia
Method Name
Immunochromatographic Membrane Assay
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
UrineOrdering Guidance
Pneumococcal pneumonia is best diagnosed by sputum culture. For more information, see SPUTS / Bacterial Culture, Aerobic, Respiratory with Antimicrobial Susceptibilities, Varies.
Specimen Required
Supplies: Urine Tubes, 10 mL (T068)
Container/Tube: Plastic, 10-mL urine tube
Specimen Volume: 2 mL
Collection Instructions:
1. Collect a random urine specimen.
2. No preservative.
3. Excessively bloody or very turbid specimens containing protein, cells, or particulates will be canceled as they can inhibit the function of the test.
4. Centrifuging to remove particulates is not approved.
5. Specimens with any dyes or unnatural color are not acceptable and will be canceled.
Specimen Minimum Volume
0.25 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Urine | Refrigerated (preferred) | 14 days | |
| Frozen | 14 days | ||
| Ambient | 24 hours |
Reject Due To
| Gross hemolysis | Reject |
| Turbid Dyes/unnaturally colored | Reject |
Reference Values
Negative
Day(s) Performed
Sunday through Friday
CPT Code Information
87899
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| SPNEU | Streptococcus pneumoniae Ag, U | 77949-6 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 83150 | Streptococcus pneumoniae Ag, U | 77949-6 |
Clinical Information
Streptococcus pneumoniae is the most frequently encountered bacterial agent of community-acquired pneumonia (CAP). 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 provided for CAP without culture confirmation of S pneumoniae, antigen testing may be useful.
Interpretation
A positive result is indicative of pneumococcal pneumonia.
Negative:
Negative for pneumococcal pneumonia, suggesting no current or recent pneumococcal infection. Infection due to Streptococcus pneumoniae cannot be ruled out since the antigen present in the sample may be below the detection limit of the test.
Cautions
A negative result does not exclude Streptococcus pneumoniae infection.
A diagnosis of S pneumoniae infection must take into consideration all test results, culture results, and the clinical presentation of the patient.
S pneumoniae vaccine may cause false-positive results, especially in patients who have received the vaccine within 5 days of having the test performed.
This assay has not been validated for use with body fluids other than urine or cerebrospinal fluid.
The performance of this assay in patients who have received antibiotics for more than 24 hours has not been established.
The accuracy of this assay has not been proven in small children.
Method Description
The Binax NOW Streptococcus pneumoniae test is an immunochromatographic membrane assay used to detect pneumococcal soluble antigen in human urine and cerebrospinal fluid. Rabbit anti-S pneumoniae and anti-species antibodies are conjugated to visualizing particles that are dried onto an inert fibrous support. The resulting conjugate pad and the striped membrane are combined to construct the test strip.
To perform the test, a swab is dipped into the specimen, removed, and then inserted into the test device. Reagent A, a buffer solution is added from a dropper bottle. The device is then closed, bringing the sample into contact with the test strip. Pneumococcal antigen present in the sample reacts to bind anti-S pneumonia-conjugated antibody. The resulting antigen-conjugate complexes are captured by immobilized anti-S pneumoniae-conjugated antibody. The resulting antigen-conjugate complexes are captured by immobilized anti-S pneumoniae antibody, forming the sample line. Immobilized control antibody captures anti-species conjugate forming the control line.
Test results are interpreted by the presence or absence of visually detectable pink-to-purple colored lines. A positive test result, read in 15 minutes depending on the concentration of antigen present in the sample, will include the detection of both a sample and control line. A negative test result, read in 15 minutes, will produce only a control line, indicating that S pneumoniae antigen was not detected in the sample. Failure of the control line to appear, whether the sample line is present or not, indicates an invalid assay.(Package insert: BinaxNOW Streptococcus pneumoniae Antigen Card. Abbott Diagnostics; 01/2020)