Intraoral Human Herpes Viruses Detectable in Majority of Immunocompetent Patients

Objectives: To quantify the intraoral prevalence of HHV using mucosal swabs, saliva samples and qPCR analysis in immunocompetent individuals with and without chronic mucosal abnormalities.
Methods: Matched saliva and oral swabs were collected from a total of 118 subjects: 70 immunocompetent subjects with no mucosal abnormalities, 22 with mucosal abnormalities and 26 therapeutically immunocompromised individuals. Extracted DNA was analyzed by multiplex qPCR for detection and quantification of Herpes simplex 1 (HSV-1), Herpes simplex 2 (HSV-2), Varicella Zoster Virus (VZV), Epstein Barr Virus (EBV), Cytomegalovirus (CMV) and HHV-6.
Results: At least one HHV was detected in 77.1% of immunocompetent individuals with no mucosal abnormalities, with EBV the most commonly detected at 63.0%. HHV-6 was detected in 23.9%, HSV-1 in 9.8% and CMV in 1.1%. Detection was higher in saliva than in swabs. There was no detection of HSV-2 or VZV. Neither presence of oral mucosal abnormality nor therapeutic immunocompromise was related to increased detection of HHV. Quantified detection levels of HSV-1 DNA was significantly higher than detection levels of EBV, HHV-6 or CMV in both swabs and saliva.
Conclusions: Commensal detection rates of EBV are high and caution in clinical interpretation of positive detection is warranted. Commensal CMV rates are low and detection by swab and saliva may be clinically relevant. The absence of HSV-2 or VZV suggests detection of these viruses by saliva or swab would be significant. This study presents the first comprehensive study into the commensal detection rates of HHV 1-6 by qPCR in non-invasive saliva and swab samples.