Pediatric Epstein-Barr Virus Carriers With or Without Tonsillar Enlargement May Substantially Contribute to Spreading of the Virus

Background. Human-to-human transmission of the persistent infection establishing Epstein-Barr virus (EBV) occurs via saliva. Tonsils act as important portal of entry and exit of EBV. The contagiousness of pediatric EBV carriers and the role played by tonsillar enlargement (TE) are not known. Methods. We compared EBV shedding in mouthwash samples from pediatric EBV carriers with or without TE to that in mouthwash samples from pediatric patients with infectious mononucleosis (IM), the symptomatic form of primary infection if delayed after the age of 5 years. EBV DNA was quantified by polymerase chain reaction, and contagiousness was assessed using the cord lymphocyte transformation assay. Results. EBV carriers with TE shed EBV DNA at an almost similar frequency (although in lower amounts) as pediatric patients with acute IM but more frequently ( ) and in higher amounts ( ) than EBVP!.001 Pp.038 carriers without TE. EBV DNA levels in mouthwash samples from EBV carriers with TE mirrored levels in tonsils and gradually declined after tonsillectomy. Almost half of the mouthwash samples from pediatric EBV carriers contained infectious EBV. Conclusions. Pediatric EBV carriers—in particular, those with TE—may considerably contribute to the spread-ing of EBV in industrialized countries. More than 90 % of the adult population carry Epstein-Barr virus (EBV), a human gammaherpesvirus that es-tablishes latency in memory B cells to persist in the host [1]. Thus, EBV is one of the most successfully spreading viruses [2]. The members of the population involved in the spreading of EBV are only incompletely defined. Human-to-human transmission of EBV occurs main-ly via saliva [1]. Palatine tonsils act as an important sit