pneumococcal-disease-tests
Reviewed
Also called: Streptococcus pneumoniae test, S. pneumoniae test, Pneumococcal Culture, Pneumococcal Antigen Test, Pneumococcal PCR Test
Pneumococcal disease tests look for pneumococcus bacteria (Streptococcus pneumoniae) in body fluids such as blood, urine, sputum, or cerebrospinal fluid. These tests help diagnose infections that can range from mild (ear or sinus infections) to severe (pneumonia, bloodstream infection, meningitis). Your provider will decide which test(s) you need based on your symptoms.
Specimen: Blood, urine, sputum, nasopharyngeal swab, or cerebrospinal fluid (CSF)
Why this test may be ordered
- To find out whether you have pneumococcal disease
- To help guide antibiotic treatment, especially if bacteria may be resistant to certain antibiotics
Preparation and collection
For most pneumococcal disease tests, you don't need any special preparation. Talk to your provider about any special preparations. You may need to fast (not eat or drink) before the test or stop taking certain medicines. Do not stop taking any medicines unless your provider tells you to.
The type of sample collected depends on your symptoms. Options include: blood draw from a vein; clean-catch urine sample; sputum sample coughed up from the lungs; nasopharyngeal swab (a long swab inserted into the nostril); or cerebrospinal fluid obtained via a spinal tap (lumbar puncture). In some cases, a bronchoscopy with bronchoalveolar lavage (BAL) may be performed to collect a sample directly from the lungs.
Blood test: very little risk; slight pain or bruising at the needle site. Urine or sputum sample: no risk. Nasopharyngeal swab: may be uncomfortable and cause coughing or gagging; all effects are temporary. Spinal tap: very little risk; you may feel a pinch or pressure, and afterward some pain or tenderness in your back or a headache that may last hours to a week. Bronchoscopy/BAL: very little risk; serious complications are rare but may include bleeding in the airways, infection, or a pneumothorax (collapse of part of your lung).
Understanding results
Your results will show whether pneumococcus bacteria were found in your specimen. Your provider will consider your symptoms, medical history, physical exam, and possibly other tests to make a diagnosis and decide on the best treatment.
- Positive: Pneumococcus bacteria were found in your specimen. You most likely have pneumococcal disease. Limitation: A positive result does not indicate the severity or specific location of infection. Your provider will interpret the result along with your symptoms and other tests. Next step: Prompt
- Negative: No pneumococcus bacteria were found in your specimen. Most likely, your symptoms are not caused by pneumococcal disease. Limitation: A negative result does not completely rule out infection if the sample was not collected from the exact site of infection or if bacteria levels were too low to detect. Next step: Routine
- Results depend on the quality and site of the sample collected.
- A negative result does not completely rule out pneumococcal disease if the sample was not from the infected site.
- Some pneumococcal bacteria may be resistant to certain antibiotics; additional testing may be needed to guide treatment.
What to do next
If you have questions about your results, talk to your provider. They may also order other tests such as a chest x-ray, complete blood count (CBC), erythrocyte sedimentation rate (ESR), or C-reactive protein (CRP) test to help make a diagnosis.
- Which type of pneumococcal test did I have?
- What do my results mean for my symptoms?
- Do I need any other tests?
- What treatment do you recommend based on these results?
Evidence source
U.S. National Library of Medicine: pneumococcal-disease-tests