Herpes Simplex Virus (HSV) and Varicella-Zoster Virus (VZV), Molecular Detection, PCR
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Herpes simplex virus (HSV) types 1 and 2 are members of the Herpesviridae family, and produce infections that may range from mild stomatitis to disseminated and fatal disease. Clinical conditions associated with HSV infection include gingivostomatitis, keratitis, encephalitis, vesicular skin eruptions, aseptic meningitis, neonatal herpes, genital tract infections, and disseminated primary infection.
Infections with HSV types 1 and 2 can differ significantly in their clinical manifestations and severity. HSV type 2 primarily causes urogenital infections and is found almost exclusively in adults. HSV type 1 is closely associated with orolabial infection, although genital infection with this virus can be common in certain populations.
The diagnosis of HSV infections is routinely made based on clinical findings and supported by laboratory testing using PCR or viral culture.
HSV causes various clinical syndromes. Anatomic sites infected include skin, lips and oral cavity, eyes, genital tract, and central nervous system.(1) Varicella-zoster virus (VZV) causes both varicella (chickenpox) and herpes zoster (shingles). VZV produces a generalized vesicular rash on the dermis (chickenpox) in normal children, usually before age 10. After primary infection with VZV, the virus persists in latent form and may emerge (usually in adults age 50 and older) clinically to cause a unilateral vesicular eruption, generally in a dermatomal distribution (shingles).
Rapid diagnosis of herpes simplex virus and varicella-zoster virus infections
Herpes Simplex Virus (HSV) PCR:
This is a qualitative assay; results are reported either as negative, positive or indeterminate for HSV type 1 or HSV type 2.
Detection of HSV DNA in clinical specimens supports the clinical diagnosis of infection due to the virus.
Varicella-Zoster Virus (VZV) PCR:
Detection of VZV DNA in clinical specimens supports the clinical diagnosis of infection due to this virus.
VZV DNA is not detected in cerebrospinal fluid from patients without central nervous system disease caused by this virus.
This LightCycler PCR assay does not yield positive results with other herpesvirus gene targets (cytomegalovirus, Epstein-Barr virus).
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
A negative result does not eliminate the possibility of herpes simplex virus (HSV) or varicella-zoster virus (VZV) infection. Inhibitors of PCR may be present in some specimens.
The reference range is typically "negative" for this assay. This assay is only to be used for patients with a clinical history and symptoms consistent with VZV or HSV infection, and must be interpreted in the context of the clinical picture. This test is not used to screen asymptomatic patients.
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.
Herpes Simplex Virus PCR
Varicella-Zoster Virus PCR
Clinical References Provides recommendations for further in-depth reading of a clinical nature
1. Schiffer JT, Corye L: New concepts in understanding genital herpes. Curr Infect Dis Rep Nov 2009;11(6):457-464
2. Espy MJ, Uhl JR, Svien KA: Laboratory diagnosis of herpes simplex virus infections in the clinical laboratory by LightCycler PCR. J Clin Microbiol 2000;38(2):795-799
3. Espy MJ, Ross TK, Teo R: Evaluation of LightCycler PCR for implementation of laboratory diagnosis of herpes simplex virus infections. J Clin Microbiol 2000;38(8):3116-3118
4. Sauerbrei A, Eichhorn U, Hottenrott G, Wutzler P: Virological diagnosis of herpes simplex encephalitis. J Clin Virol 2000;17(1):31-36
5. Mitchell PS, Espy MJ, Smith TF, et al: Laboratory diagnosis of central nervous system infections with herpes simplex virus by PCR performed with cerebrospinal fluid specimens. J Clin Microbiol 1997;35(11):2873-2877
6. Yi-Wei T, Mitchell PS, Espy MJ, et al: Molecular diagnosis of herpes simplex virus infections in the central nervous system. J Clin Microbiol 1999;37(7):2127-2136
7. Cinque P, Bossolasco S, Vago L, et al: Varicella-zoster virus (VZV) DNA in cerebrospinal fluid of patients infected with human immunodeficiency virus: VZV disease of the central nervous system or subclinical reactivation of VZV infection? Clin Infect Di1997;25(3):634-639
8. Brown M, Scarborough M, Brink N, et al: Varicella zoster virus-associated neurological disease in HIV-infected patients. Int J STD AIDS 2001;12(2):79-83
9. Studahl M, Hagberg L, Rekabdar E, Bergstrom T: Herpesvirus DNA detection in cerebrospinal fluid: differences in clinical presentation between alpha-, beta-, and gamma-herpesviruses. Scand J Infect Dis 2000;32(3):237-248
10. Iten A, Chatelard P, Vuadens P, et al: Impact of cerebrospinal fluid PCR on the management of HIV-infected patients with varicella-zoster virus infection of the central nervous system. J Neurovirol 1999;5(2):172-180