Evaluation of the Cepheid herpes simplex virus typing real-time PCR assay using dermal and genital specimens

Clinical validation of the Lyra direct HSV 1+2/VZV assay for simultaneous detection and differentiation of three herpesviruses in cutaneous and mucocutaneous lesions

We evaluated the Lyra Direct HSV 1+2/VZV multiplex real-time PCR assay for the detection and differentiation of herpes simplex virus 1 (HSV-1), HSV-2, and varicella-zoster virus (VZV) on 695 consecutive cutaneous and mucocutaneous lesion specimens. The intra-assay and interassay coefficient of variation values for the Lyra assay were 0.29 to 1.30% and 2.33 to 2.61%, respectively. The sensitivities, specificities, and positive and negative predictive values were 93.4 to 95.0%, 96.1 to 96.8%, 78.0 to 80.3%, and 99.0 to 99.1%, respectively, in comparison to those of viral culture. The values were further improved when a resolution analysis was performed with a laboratory-developed PCR assay.

Comparison of two multiplexed PCR assays for the detection of HSV-1, HSV-2, and VZV with extracted and unextracted cutaneous and mucosal specimens

BACKGROUND

Several analyte specific reagents (ASRs) are available for the detection and differentiation of HSV-1, HSV-2, and VZV in clinical specimens. However, there is limited data on the test performance of these reagents used in multiplexed PCR assays.

OBJECTIVE

This study compared the performance of two multiplexed ASR sets for detection of HSV-1, HSV-2, and VZV in dermal specimens.

STUDY DESIGN

Two commercially available ASRs were combined to produce multiplexed PCR assays for simultaneous detection of HSV-1, HSV-2, and VZV. Seeded samples were used to determine the limit of detection (LOD) for each assay. Patient samples (n=156) were tested in duplicate and results for each method compared to the reference standard of culture. Both extracted and unextracted specimens were used in the study.

RESULTS

Both multiplexed PCR assays showed similar test performance, with minimal LOD differences observed. The LOD was 10(3) copies/mL for HSV-1 and HSV-2 using the Focus assay compared to 5×10(3) copies/mL and 2×10(4) copies/mL, respectively for the EraGen assay. Both assays showed equal performance for VZV with a LOD of 5×10(3) copies/mL. Analytical specificity testing showed no cross reactivity with other selected DNA viruses. Both assays showed similar performance when clinical samples were tested using both extracted and unextracted specimens.

CONCLUSION

Commercially available ASRs can be successfully multiplexed for the PCR detection of HSV-1, HSV-2, and VZV using dermal specimens. Either direct testing or nucleic acid extracted specimens can be used with similar performance in these assays.

Molecular detection of herpesviruses

In routine molecular diagnostics, detection of herpesviruses has made a major impact. Infection with herpesviruses is indicated by demonstrating the presence of the virus in selected specimens. Rapid and reliable detection of herpesvirus DNA helps to decrease the lethality as well as the sequelae of herpesvirus infection in patients at risk. This chapter discusses specimen types and both laboratory-developed and commercially available assays useful for molecular detection of herpesviruses. To meet the need for reliable laboratory results, it is advisable to employ maximum automated and standardized kits based on reagents and standards of reproducible high quality. In the routine diagnostic laboratory, introduction of IVD/CE and/or FDA-labeled tests is preferred.

Evaluation of real-time polymerase chain reaction assays for the detection of herpes simplex virus in swab specimens

An in-house herpes simplex virus (HSV) real-time polymerase chain reaction (PCR) hydrolysis probe assay and three commercial real-time HSV assays were evaluated for the detection of HSV from genital, oral, ocular and dermal clinical samples. Five hundred and sixty samples from patients displaying signs and symptoms of HSV infection were used to evaluate the in-house HSV assay. A representative 151 samples were processed using the artus HSV-1/2 TM PCR Kit, SmartCycler Non-typing and SmartCycler Typing ASR kits. The in-house PCR assay demonstrated an overall positivity rate of 38% (211/560), equating to a 14% increase in HSV detection compared to 24% for culture (135/560). All 76 culture-negative, in-house PCR-positive samples were confirmed using at least one HSV commercial kit. The in-house, SmartCycler Non-typing, artus and SmartCycler Typing assays showed improved sensitivity (100%, 100%, 98% and 99%, respectively) compared to culture (37%), and all real-time assays were highly specific (100%). The in-house and commercial real-time HSV PCR assays performed well and, combined with careful clinical interpretation, should improve the detection, differentiation and quantification of HSV from mucocutaneous swab samples.