Background Genital lesions can be caused by herpes simplex virus types 1 and 2 (HSV-1 and HSV-2), varicella zoster virus (VZV) and Treponema pallidum (TP). Clinical presentations can be indistinguishable, and correct identification of the etiology is essential for patient management. PCR is the gold standard for identification of herpes viruses, and PCR can also be used for direct detection of TP from genital lesions. Given the recent global resurgence of syphilis, early diagnosis using PCR is an important tool to supplement serology-based diagnosis of syphilis.

Methods The PlexPCR^® VHS assay (SpeeDx) has been developed to detect and differentiate HSV-1, HSV-2, VZV and TP. 211 samples (157 positive and 54 negative) were collected from Melbourne Sexual Health Centre (Victoria, Australia) from January-April 2018. Samples consisted of genital, anal/rectal, oral and non-genital swabs. The performance of the assay was evaluated at the Victorian Infectious Diseases Reference Laboratory (Victoria, Australia) and compared to reference results from in-house qPCR tests (HSV-1/HSV-2/VZV/CMV multiplex and TP singleplex). TP detection was also compared to serology results.

Results The sensitivity/specificity of each target compared to in-house qPCR was 100%/99.4% for HSV-1, 96.0%/98.8% for HSV-2, 100%/100% for VZV and 100.0%/100.0% for TP. Analysis of TP PCR results compared to serology are still pending.

Conclusion Molecular diagnosis of genital lesions using PlexPCR VHS allows rapid identification of pathogens with high sensitivity and specificity, enabling appropriate patient management.

Disclosure No significant relationships.