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HelpEpic Test Code LAB4959 Herpes Simplex Virus (HSV), Molecular Detection, PCR, Spinal Fluid
Additional Codes
MML:HSVC
Useful For
Aiding in the rapid diagnosis of herpes simplex virus (HSV)-1 and HSV-2 infections of the central nervous system
Method Name
Real-Time Polymerase Chain Reaction (RT-PCR)
Reporting Name
Herpes Simplex Virus, PCR, CSFSpecimen Type
CSFSpecimen Required
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Container/Tube: Plastic vial
Specimen Volume: 0.2 mL
Collection Instructions:
1. Submit from second spinal fluid collection vial.
2. Transfer into aliquot vial using sterile technique.
3. Do not centrifuge or heat inactivate.
Additional Information:
1. The high sensitivity of amplification by polymerase chain reaction (PCR) requires the specimen to be processed in an environment in which contamination of the specimen by herpes simplex virus DNA is not likely.
2. Specimens that are received with less than the minimum volume required for all testing requested will be canceled.
Specimen Minimum Volume
0.1 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| CSF | Refrigerated (preferred) | 7 days | |
| Frozen | 7 days |
Reject Due To
| Heat-treated spinal fluid | Reject |
Clinical Information
Herpes simplex virus (HSV)-1 and HSV-2 are members of the Alpha herpesviridae subfamily. HSV is an enveloped virus with a capsid containing viral DNA. Although HSV-1 and HSV-2 are closely related, the 2 viruses are serologically and genetically distinct.(1,2)
HSV-1 and -2 are common causes of dermal and genital infections; however, in some cases, infection with HSV may result in central nervous system (CNS) disease that is considered a medical emergency. HSV infection of the CNS may result in encephalitis (more commonly associated with HSV-1) or meningitis (more commonly associated with HSV-2).
Encephalitis is inflammation of the brain associated with clinical evidence of neurologic dysfunction. Of the pathogens reported to cause encephalitis, the majority are viruses.(3) In general, the most frequently identified etiologies in the United States are HSV, West Nile virus, and the enteroviruses, followed by other herpesviruses.(3)
HSV causes about 5% to 10% of all encephalitis cases and is one of the most common causes of identified sporadic encephalitis globally.(3) HSV encephalitis occurs in all ages, and during all seasons. HSV-1 encephalitis is more common in adults, and HSV-2 encephalitis is more common in neonates.(3) One study reported a neonatal herpes rate of 1 case per 3200 live births in the United States.(4)
Clinical features involved with HSV encephalitis include fever, hemicranial headache, language and behavioral abnormalities, memory impairment, and seizures.(3)
Reference Values
Negative
Interpretation
A positive result suggests the presence of herpes simplex virus (HSV)-1 and/or HSV-2 DNA in the cerebrospinal fluid (CSF) sample.
A negative result suggests that HSV-1 and HSV-2 DNA are not present in the CSF sample.
An invalid result points to the inability to determine presence or absence of HSV-1 or HSV-2 DNA in the CSF sample.
Cautions
This test is not validated for sample types other than cerebrospinal fluid (CSF).
Negative results do not preclude herpes simplex virus (HSV)-1 or HSV-2 infection and should not be used as the sole basis for treatment or other patient management decisions.
False-negative results may occur if the viruses are present at a level that is below the analytical sensitivity of the assay or if the virus has genomic mutations, insertions, deletions, or rearrangements, or if the assay is performed very early in the course of illness.
For encephalitis patients with a negative herpes simplex PCR result, consideration should be given to repeating the test 3 to 7 days later for patients demonstrating a compatible clinical syndrome or temporal lobe localization on neuroimaging.(3)
The performance of this test has not been established for immunocompromised individuals, nor has it been established for monitoring treatment of HSV infection of the central nervous system.
Supportive Data
Accuracy:
To assess the accuracy of the Diasorin Simplexa HSV (herpes simplex virus)-1 and -2 Direct assay, clinical spinal fluid (CSF) specimens (n=100) were tested and the results compared to those of the Roche HSV-1/2 analyte specific reagents.(6) Samples showing discordant results were tested by a third method (artus HSV-1/2; Qiagen). The results are summarized below in Tables 1 and 2:
Table 1. Comparison of the Simplexa HSV-1 Direct Assay to the Roche ASR using Clinical CSF Samples (n=100)(a).
|
Simplexa HSV-1 |
|
Roche HSV-1 ASR (b) |
|
|
Positive |
Negative |
||
|
Positive |
11 |
0 |
|
|
Negative |
0 |
85 |
|
|
Total |
11 |
85 |
|
Sensitivity (95% CI): 100% (70-100)
Specificity (95% CI): 100% (94.8-100)
Table 2. Comparison of the Simplexa HSV-2 Direct Assay to the Roche ASR using Clinical CSF Samples (n=100)(a).
|
Simplexa HSV-2 |
|
Roche HSV-2 ASR (b) |
|
|
Positive |
Negative |
||
|
Positive |
37 |
1 |
|
|
Negative |
0 |
58 |
|
|
Total |
37 |
59 |
|
Sensitivity (95% CI): 100% (88.8-100)
Specificity (95% CI): 98.3% (90.2-99.9)
(a) Only 96 samples are summarized. This is because 4 samples were found to be HSV detected-type indeterminate by the Roche ASR. These results are summarized in footnote b.
(b) One sample was HSV detected-type indeterminate by the Roche ASR and positive for HSV-1 by the Diasorin Simplexa assay. In addition, 3 samples were HSV detected-type indeterminate by the Roche ASR but negative by the Simplexa HSV-1 assay. These 3 samples were tested by a third method (artus HSV-1/2; Qiagen) and were negative for HSV-1 and -2. Testing was also repeated by the Roche ASR and the results were negative upon repeat testing.
Day(s) Performed
Monday through Sunday
Report Available
Same day/1 to 2 daysSpecimen Retention Time
7 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
87529 x 2
87529 (if appropriate for government payers)
NY State Approved
YesTesting Algorithm
For more information see Meningitis/Encephalitis Panel Algorithm.
Special Instructions
Forms
If not ordering electronically, complete, print, and send a Microbiology Test Request (T244) with the specimen.