Establishment of multiplex Real-Time PCR assay for simultaneous detection of Herpes simplex virus and Varicella-zoster virus

The herpes simplex viruses types 1 and 2 (HSV-1 and HSV-2) and varicella-zoster virus (VZV) can cause life-threatening infections of the central nervous system and lead to severe disease in newborns and immunosuppressed patients. In these cases, rapid diagnosis is crucial. We have successfully established a process to simultaneously detect of HSV and VZV by multiplex real-time PCR using Taqman probes based on primers/probe from the DNA polymerase genes of those viruses. The performance of these techniques was assessed by analyzing serial dilutions of DNA known concentrations and the lowest limit of detection was found to be 102 DNA copies/ml. Of the 83 clinical samples collected from Tropical Diseases Hospital in HoChiMinh city and National Dermatology Hospital, 8/83 samples were infected with HSV, 10/83 samples were infected with VZV and 1/83 sample was co-infected with both HSV and VZV. The PCR results were confirmed by DNA sequencing showing 100% specificity. The method will be further tested on larger number of samples before being put into clinical application.