Detection of Epstein-Barr virus DNA in mouthwashes by hybridization

An assay for the presence of Epstein-Barr virus (EBV) DNA was developed by using a cloned EBV DNA probe. After preliminary testing showed the assay to be sensitive and specific, it was applied to 135 mouthwashes from bone marrow transplant recipients, and 21 of these tests were positive. The concentration of EBV DNA in mouthwashes in some cases was as high as 10(8) genome equivalents per ml. When compared with the lymphocyte transformation assay on the same samples, the sensitivity was 75% and the specificity was 97%. In contrast to the lymphocyte transformation assay, the hybridization was semiquantitative and yielded results in 72 h. Potential applications include monitoring the effects of various interventions, such as immunosuppressive and antiviral chemotherapy, on EBV shedding.