Epstein-Barr Virus DNA in Parental Oral Secretions: A Potential Source of Infection for Their Young Children.

Background. A potential source of primary Epstein-Barr virus (EBV) infection for young children is parental oral secretions. If parents who identify with racial/ethnic categories other than white have a higher prevalence of oral EBV DNA, this difference could explain why their children acquire primary EBV infection at an earlier age than white children. Methods. To test this hypothesis, we recruited parents who brought their children <8 years old to routine clinic visits, and tested the parents' oral washes for EBV DNA by real-time polymerase chain reaction. Positive samples were assayed for encapsidated EBV DNA, which is potentially infectious, versus naked EBV DNA, which is not infectious. Results. Overall, 221/800 parents (28%) had EBV DNA in their oral washes. Oral EBV DNA was more prevalent in parents who identified as non-white as compared with white parents (P = .0004), and was more prevalent in male vs female parents (P = .04). The mean quantity of EBV DNA in positive samples was 5000 copies/mL. Encapsidated viral DNA comprised 40.3% of the total EBV DNA found in parental oral secretions. Conclusions. Our data support the hypothesis that parents could be a source of virus for their young children, because 28% of parents had a mean of 5000 EBV copies/mL of oral wash and 40.3% of the EBV DNA was encapsidated. The higher prevalence of EBV DNA in non-white parents could explain why their children acquire EBV at an earlier age than children of white parents.