Detection of herpes simplex virus type 1, herpes simplex virus type 2 and varicella-zoster virus in skin lesions. Comparison of real-time PCR, nested PCR and virus isolation.
BACKGROUND
Herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2 (HSV-2) and varicella-zoster virus (VZV) cause a wide range of signs and symptoms, varying from trivial mucocutaneous lesions to life-threatening infections, especially in immuno-suppressed patients. Since antiviral drugs are available, rapid and sensitive laboratory diagnosis of these virus infections is important.


OBJECTIVE
To set up and evaluate HSV-1, HSV-2 and VZV qualitative real-time PCR on the Lightcycler system and to compare the results with those of the 'in-house' nested PCR and virus isolation.


METHODS
110 consecutive samples from dermal or genital lesions from patients suspected of having HSV infections and another 110 samples from patients with suspected VZV infections were tested with real-time PCR, nested PCR and virus isolation.


RESULTS
24 samples (22%) were positive for HSV-1 by virus isolation and nested PCR, whereas 26 (24%) were positive by real-time PCR. HSV-2 was detected in 28 samples (25%) by virus isolation, in 41 (37%) by nested PCR and in 40 (36%) by real-time PCR. VZV was isolated in 15 samples (14%) and VZV DNA was detected in 51 samples (46%) by nested PCR as well as by real-time PCR. Nucleic acid amplification increased the detection rate of HSV-2 and VZV DNA in particular compared to virus isolation. No significant difference in sensitivity was found between real-time PCR and nested PCR.


CONCLUSIONS
Real-time PCR has the advantage of rapid amplification, a reduced risk for contamination and it is a suitable method for diagnosis of VZV and HSV in specimens from skin lesions.
Schmutzhard
Julia
J
Department of Clinical Microbiology, Section of Virology, Karolinska Hospital, SE-17176 Stockholm, Sweden.
Merete Riedel
Hilde
H
Zweygberg Wirgart
Benita
B
Grillner
Lena
L
D002644:Chickenpox / Q000175:diagnosis / Q000821:virology; D019411:Clinical Laboratory Techniques / Q000379:methods; D004279:DNA, Viral / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D005814:Genes, Viral; D006558:Herpes Genitalis / Q000175:diagnosis / Q000821:virology; D006561:Herpes Simplex / Q000175:diagnosis / Q000821:virology; D018259:Herpesvirus 1, Human / Q000145:classification / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification*; D018258:Herpesvirus 2, Human / Q000145:classification / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification*; D014645:Herpesvirus 3, Human / Q000145:classification / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification*; D006801:Humans; D016133:Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D017193:Skin Diseases, Viral / Q000175:diagnosis / Q000821:virology*; D044366:Transition Temperature
D004279:DNA, Viral