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Test ID: HHV6 Human Herpesvirus-6, Molecular Detection, PCR, Plasma

Reporting Name


Useful For

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

Clinical Information

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 [VZV], CMV, Epstein-Barr virus [EBV], 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)


A positive result indicates the presence of specific DNA from human herpesvirus-6 (HHV-6) and supports the diagnosis of infection with this virus.


A negative result indicates the absence of detectable DNA from HHV-6 in the specimen, but it does not negate the presence of the virus or active or recent disease.

Report Available

2 to 5 days

Day(s) Performed

Monday through Friday

Clinical Reference

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 Name

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

Specimen Type

Plasma EDTA

Specimen Required

Supplies: Aliquot Tube, 5 mL (T465)

Collection Container/Tube: Lavender top (EDTA)

Submission Container/Tube:

Preferred: Aliquot Tube, 5 mL (T465)

Acceptable: Screw-capped, sterile container

Specimen Volume: 1 mL

Collection Instructions: Spin down promptly.

Specimen Minimum Volume

0.3 mL

Specimen Stability Information

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

Reference Values


Test Classification

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


LOINC Code Information

Test ID Test Order Name Order LOINC Value
HHV6 HHV-6 PCR, P 29495-9


Result ID Test Result Name Result LOINC Value
87532 HHV-6 PCR, P 29495-9


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

Mayo Clinic Laboratories | Neurology Catalog Additional Information:

mml-CNS-Infections, mml-Pediatric