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.

Age-specific prevalence of Epstein-Barr virus infection among Minnesota children: effects of race/ethnicity and family environment.

BACKGROUND: Primary Epstein-Barr virus (EBV) infection affects the host differently according to when in life it is acquired. Understanding risk factors for infection could be important for disease prevention, and the age-specific prevalence of infection must be known to optimize use of a prophylactic vaccine. METHODS: Children 18 months to 19.9 years of age who had blood drawn for medical indications during an outpatient visit were eligible. Sera were tested for immunoglobulin G antibodies against EBV viral capsid antigen by enzyme immunoassay. Family demographic and socioeconomic data were obtained via scripted telephone questionnaires. RESULTS: Consent was given for 876 of 914 (96%) subjects approached. Sera were available for 782 of 876 (89%) subjects and demographic/socioeconomic data obtained for 705 (90%) of them. Antibody prevalence, adjusted for age and sex, was as follows: non-Hispanic blacks, 74%; Asians, 62%, multiracial children, 54%; Hispanics, 50%; and non-Hispanic whites, 26%. The pattern of increases in antibody prevalence with age differed significantly by race/ethnicity, and was most divergent in the 2 youngest age groups. Adjusted EBV antibody prevalence decreased with greater household education among non-Hispanic whites, but was not associated with any other socioeconomic factor. In 42 of 51 (82%) families with >1 child in the study, the siblings' EBV antibody status was concordant (bootstrap P < .001). CONCLUSIONS: Racial/ethnic differences in EBV antibody prevalence and concordance of antibody status among siblings prompt us to speculate that both genetics and family environment contribute to acquisition of EBV infection. The ideal age to give a prophylactic vaccine may differ according to race/ethnicity.