Performance characteristics of the SpeeDx PlexPCR VHS assay for the molecular detection of herpes simplex virus, varicella zoster virus, and Treponema pallidum in lesion swabs.

This study compares the performance of a commercial polymerase chain reaction (PCR) assay for detection of herpes simplex virus (HSV) 1 and 2, varicella zoster virus (VZV), and Treponema pallidum with laboratory-developed assays. A panel of 250 samples, previously tested using in-house assays, was tested on the PlexPCR® VHS assay. The panel consisted of 202 positive specimens [HSV-1 (n=51); HSV-2 (n=51); VZV (n=51); T. pallidum (n=49)] and 48 negative specimens. Genital samples had been previously tested for HSV-1/2 and T. pallidum and nongenital or unspecified samples for HSV-1/2 and VZV. The overall agreement between the PlexPCR® VHS and in-house assays was 97%. Negative agreement was ≥99%, and positive agreement for individual targets was 96% (47/49) for T. pallidum, 98% for HSV-1 and HSV-2 (50/51), and 100% (51/51) for VZV. Adoption of this assay would allow greater availability of molecular syphilis detection and enhance the diagnostic yield of samples collected from cutaneous/mucocutaneous lesions.