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Lab Dept:
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Microbiology/Virology
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Test Name:
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ENTEROVIRUS RNA DETECTION BY NASBA, CSF
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General Information
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Lab Order Codes:
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EVNA
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Synonyms:
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Enterovirus RT PCR; PCR for Enterovirus; CSF for Enterovirus; Enterovirus NASBA
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CPT Codes:
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87498 – Enterovirus, amplified probe technique
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Test Includes:
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Detection of enterovirus by nucleic acid sequenced-based amplification (NASBA)
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Logistics
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Lab Testing Sections:
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Microbiology/Virology
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Phone Numbers:
Minneapolis:
Saint Paul:
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612-813-7103
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612-813-7103
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Test Availability:
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Specimens accepted daily, 24 hours
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Turnaround Time:
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24 – 48 hours
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Special Instructions:
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Requisition must state specific site of specimen and date/time of collection.
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Specimen
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Specimen Type:
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CSF
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Container:
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Sterile container
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Collection:
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1. Disinfect skin site with 2% tincture of iodine.
2. Insert needle with stylet at L3 – L4, L4 – L5, or L5 –S1 interspace.
3. Upon reaching the subarachnoid space, remove the stylet and collect
1–2 mL of fluid into each of 3 sterile CSF tubes.
4. Deliver to Laboratory immediately.
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Transport/Storage:
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Transport to the Laboratory immediately at room temperature. If a delay is anticipated, refrigerate specimen up to 48 hours at 4 degrees C. If specimens cannot be processed within 24 hours, then the specimen should be frozen immediately upon receipt and transported on dry ice.
Stability:
Ambient: 1 hour
Refrigerated: 48 hours
Frozen: 3 months
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Specimen Volume:
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CSF: 1.0 mL (Minimum: 0.5 mL)
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Special Processing:
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Lab Staff: Accession and refrigerate specimen. Do not enter tube unless absolutely necessary to prevent nuclease contamination which will destroy the virus. If aliquoting is required, remove aliquot using sterile technique. An RMK tube will be set up if volume permits by Molecular staff. Priority will be NASBA testing (Nucleic acid sequenced based amplification) due to the increased assay sensitivity.
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Sample Rejection:
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Specimen submitted in a non-sterile or leaking transport container; improperly labeled specimen; insufficient volume; samples exposed to repeated freeze/thaw cycles; prolonged transport time; improper storage conditions. If an unacceptable specimen is received, the patient’s caregiver will be notified.
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Interpretive
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Reference Range:
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Negative: Enterovirus nucleic acid not detected by NASBA
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Critical Values:
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Positive: Enterovirus nucleic acid detected by NASBA. All positive results will be called to the physician or patient’s caregiver.
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Limitations:
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A negative result does not rule out the possibility of enterovirus infection in the CNS.
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Methodology:
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Nucleic acid sequenced-based amplification (NASBA). The NASBA assay amplifies a highly conserved region of the enterovirus genome. The detection uses target-specific molecular beacons comprised of a specific nucleotide sequence that recognizes the enterovirus RNA sequence.
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Additional Information:
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- Proper handling and storage is very important to prevent the destruction of the target RNA by RNases that can be introduced by human hands. Gloving is recommended when handling these specimens. Storage at -70º C also helps stabilize the nucleic acid.
- The enterovirus group includes the polioviruses, echoviruses, coxsackievirus A and coxsackievirus B.
- This assay does not detect parechovirus 1-6.
- During the summer and the fall, enteroviruses account for over half of the cases involving infants seen in the emergency room presenting with a fever and no other symptoms. More than 90% of community-acquired cases of viral meningitis are caused by coxsackievirus serotypes B2 and B5, and echoviruses 4,6,9,11,16, and 30.
- Children’s Hospitals and Clinics of Minnesota submits all isolates to MDH for serotyping and surveillance to monitor patterns of enterovirus circulation.
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References:
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York, M., 2004, Section 3. Aerobic bacteriology, 3.7.2. In H.D. Isenberg (ed) Clinical Microbiology Procedures Handbook. 2nd edition, vol. 1, American Society for Microbiology, Washington, D.C.
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Miller, J. Michael, 1999, A Guide To Specimen Management in Clinical Microbiology, American Society for Microbiology, Washington, D.C.
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Nolte, F.S. and A. Caliendo, 2003, Molecular Detection and Identification of Microorganisms, In P.R. Murray et al., (ed.), Manual of Clinical Microbiology, 8th edition, American Society for Microbiology, Washington, D.C., pg 247.
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Virus Particles, volume 5.5, Chemicon International, Inc., 28820 Single Oak Drive, Temecula, CA 92590.
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Updates:
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8/10/2009: Minimum volume increased from 0.3 mL to 0.5 mL.
11/30/2011: CPT update, previously listed as 87798. Limitation addition regarding parechovirus detection. Extended refrigerated storage from 24 to 48 hrs after collection.
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