Definition and Use
- This test in intended for the rapid initial detection of Streptococcus pneumoniae, Haemophilus influenzae type b, group B beta-hemolytic Streptococcus (GBS), or Neisseria meningitidis in CSF. The indication for this test is limited. Published reports have demonstrated limited sensitivity for the detection of patients with meningitis caused by common pathogens, and test results rarely result in changes to the management or therapy of patients. There may be some utility in patients who have been treated with antibiotics prior to CSF collection. There is some evidence that the performance for initial detection of GBS meningitis in neonates is acceptable.
- Latex particles are coated with antibodies directed against specific antigens of the pathogens noted above. Agglutination should occur if the antigen is present in CSF, as either a free antigen or intact bacterial cells. Specimens are collected and transported according to directions for CSF culture.
- Turnaround time: <4 hours
Interpretation
- Expected results: Negative; no agglutination means that a CSF infection caused by specific pathogen is less likely. Positive agglutination for specific latex reagent: CSF infection caused by the specific pathogen is more likely.
Limitations
- The sensitivity and specificity are too low to be recommended for routine use. Results are unlikely to change patient therapy or management.
Suggested Readings
1Perkins ‚ MD, Mirrett ‚ S, Reller ‚ LB. Rapid bacterial antigen detection is not clinically useful. J Clin Microbiol. 1995;30(06):1486 " “1491. 2Ringelmann ‚ R, Heym ‚ B, Kniehl ‚ E. Role of immunologic tests in diagnosis of bacterial meningitis. Antibiot Chemother. 1992;45:68 " “78.