Test Catalog

Test Id : HHV6V

Human Herpesvirus-6, Molecular Detection, PCR, Spinal Fluid

Useful For
Suggests clinical disorders or settings where the test may be helpful

As an adjunct in the rapid diagnosis of human herpesvirus-6 infection in cerebrospinal fluid specimens

Method Name
A short description of the method used to perform the test

Real-Time Polymerase Chain Reaction (PCR)/DNA Probe Hybridization

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.


Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

HHV-6 PCR, Varies

Lists additional common names for a test, as an aid in searching

Exanthem Subitum

Herpes Virus-6

HHV-6 (Human Herpes Virus-6)

Human Herpes Virus-6 (HHV-6)

Roseola Infantum

Specimen Type
Describes the specimen type validated for testing



Question ID Description Answers
SS012 Specimen Source

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Supplies: Sarstedt 5 mL Aliquot Tube (T914)


Preferred: Aliquot Tube

Acceptable: Sterile vial

Specimen Volume: 0.5 mL

Collection Instructions: Do not centrifuge.


If not ordering electronically, complete, print, and send a Microbiology Test Request (T244) with the specimen.

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

0.3 mL

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
CSF Refrigerated (preferred) 7 days
Frozen 7 days

Useful For
Suggests clinical disorders or settings where the test may be helpful

As an adjunct in the rapid diagnosis of human herpesvirus-6 infection in cerebrospinal fluid specimens

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Human herpesvirus-6 (HHV-6) is a member of the Herpesviridae family. These viruses contain DNA surrounded by a lipid envelope. Among members of this group, this virus is most closely related to cytomegalovirus (CMV) and HHV-7. As with other members of the herpesvirus group (herpes simplex virus [HSV] 1, HSV 2, varicella zoster virus, CMV, Epstein-Barr virus, HHV-7, HHV-8), HHV-6 may cause primary and reactivated infections subsequent to latent association with cells.(1) Infection with HHV-6 occurs early in childhood. Most adults (80%-90%) have been infected with this virus.  


HHV-6 was first linked with exanthem subitum (roseola infantum) in 1998; since then, the virus has been associated with central nervous system disease almost exclusively in immunocompromised patients.(1) HHV-6 is commonly detected in patients posttransplantation. Clinical symptoms associated with this viral infection include febrile illness, pneumonitis, hepatitis, encephalitis, and bone marrow suppression. However, the majority of HHV-6 infections are asymptomatic.(2) The incidence of HHV-7 infection and its clinical manifestations posttransplantation are less well characterized.


HHV-6 is designated as variant A (HHV-6A) or variant B (HH6-B) depending on restriction enzyme digestion patterns and on its reaction with monoclonal antibodies. Generally, variant B has been associated with exanthem subitum, whereas variant A has been found in many immunosuppressed patients.(3)

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.


Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

The sensitivity of the assay is very dependent upon the quality of the specimen submitted.


A negative test does not exclude infection with human herpesvirus-6 virus. Therefore, the results obtained should be used in conjunction with clinical findings to make an accurate diagnosis.


This assay detects nucleic acid, and therefore, cannot distinguish between viable and nonviable virus. Test performance depends on viral load in the specimen and may not correlate with cell culture performed on the same specimen.

Supportive Data

A total of 32 plasma samples and 30 cerebrospinal fluid (CSF) samples were spiked with human herpesvirus-6 (HHV-6) plasmid control at the limit of detection (LoD) (25-50 copies/mcL). The 62piked specimens were run in a blinded manner along with 28 negative (nonspiked) plasma and 30 negative (nonspiked) CSF specimens. Of the spiked specimens, 100% were positive; of the nonspiked specimens, 100% were negative.

Analytical Sensitivity/LoD:

The lower LoD of this assay is 25 to 50 DNA target copies per mcL (in plasma).


Analytical Specificity:

No PCR signal was obtained from extracts of 25 viral, bacterial and fungal isolates that can cause similar symptoms as HHV-6 infection.



Interassay precision was 100% and intra-assay precision was 100%.


Reference Range:

Although the reference range is typically "negative" for this assay, this assay may detect viremia in asymptomatic individuals. However, this assay is only to be used for patients with a clinical history and symptoms consistent with HHV-6 infection, and must be interpreted in the context of the clinical picture. This test should not be used to screen asymptomatic patients.


Reportable Range:

This is a qualitative assay and results are reported either as negative or positive for targeted HHV-6 DNA.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. De Bolle L, Naesens L, De Clercq E: Update on human herpesvirus 6 biology, clinical features, and therapy. Clin Microbiol Rev 2005 Jan;18(1):217-245

2. Dockrell DH, Paya CV: Human herpesvirus-6 and -7 in transplantation. Rev Med Virol 2001 Jan-Feb;11(1):23-36

3. Abdel-Haq NM, Asmar BI: Human herpesvirus 6 (HHV6) infection. Indian J Pediatr 2004 Jan;71(1):89-96

4. Dockrell DH, Smith TF, Paya CV: Human herpesvirus 6. Mayo Clin Proc 1999 Feb;74(2):163-170

Method Description
Describes how the test is performed and provides a method-specific reference

Viral nucleic acid is extracted by the MagNA Pure automated instrument (Roche Applied Science) from clinical specimens. Primers directed to the immediate early gene of human herpesvirus-6 (HHV-6), produce a 195 bp amplicon. The LightCycler instrument (Roche Applied Science) amplifies and monitors the development of target nucleic acid sequences after the annealing step during PCR cycling. This automated PCR system can rapidly (1 hour) detect amplicon development through stringent air-controlled temperature cycling and capillary cuvettes. The detection of amplified products is based on the fluorescence resonance energy transfer (FRET) principle. For FRET product detection, a hybridization probe with a donor fluorophore, fluorescein, on the 3'-end is excited by an external light source and emits light that is absorbed by a second hybridization probe with an acceptor fluorophore, LC-Red 640, at the 5'-end. The acceptor fluorophore then emits light of a different wavelength that can be measured with a signal that is proportional to the amount of specific PCR product. LightCycler hybridization probes are designed for exact homology to HHV-6.(Cockerill FR III, Uhl JR: Applications and challenges of real-time PCR for the clinical microbiology laboratory. In Rapid Cycle Real-Time PCR Methods and Applications. Edited by U Reischel, C Wittwer, F Cockerill. Berlin, Germany, Springer-Verlag, 2002 pp 3-30)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information


Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday, Wednesday, Friday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

2 to 5 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

1 week

Performing Laboratory Location
Indicates the location of the laboratory that performs the test


Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their Regional Manager. For assistance, contact Customer Service.

Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.


LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
HHV6V HHV-6 PCR, Varies 33942-4
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
SS012 Specimen Source 31208-2
56092 HHV-6 PCR, Varies 33942-4

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports