Early and reliable detection of herpes simplex virus type 1 and varicella zoster virus DNAs in oral fluid of patients with idiopathic peripheral facial nerve palsy: Decision support regarding antiviral treatment?

Idiopathic peripheral facial nerve palsy has been associated with the reactivation of herpes simplex virus type 1 (HSV-1) or varicella zoster virus (VZV). In recent studies, detection rates were found to vary strongly which may be caused by the use of different oral fluid collection devices in combination with molecular assays lacking standardization. In this single-center pilot study, liquid phase-based and absorption-based oral fluid collection was compared. Samples were collected with both systems from 10 patients with acute idiopathic peripheral facial nerve palsy, 10 with herpes labialis or with Ramsay Hunt syndrome, and 10 healthy controls. Commercially available IVD/CE-labeled molecular assays based on fully automated DNA extraction and real-time PCR were employed. With the liquid phase-based oral fluid collection system, three patients with idiopathic peripheral facial nerve palsy tested positive for HSV-1 DNA and another two tested positive for VZV DNA. All patients with herpes labialis tested positive for HSV-1 DNA and all patients with Ramsay Hunt syndrome tested positive for VZV DNA. With the absorption-based oral fluid collection system, detections rates and viral loads were found to be significantly lower when compared to those obtained with the liquid phase-based collection system. Collection of oral fluid with a liquid phase-based system and the use of automated and standardized molecular methods allow early and reliable detection of HSV-1 and VZV DNAs in patients with acute idiopathic peripheral facial nerve palsy and may provide a valuable decision support regarding start of antiviral treatment at the first clinical visit.