Detection of a Transformation-Incompetent Epstein-Barr Virus Genotype in a Seronegative Host

Manifestations of Epstein-Barr virus (EBV) infection are diverse, ranging from asymptomatic seroconversion to active disease. There is no evidence that this pathogenic diversity is secondary to strain differences, although EBV genotypes with and without the capacity to immortalize lymphocytes have been described in vitro (1,2). Means to propagate and analyse nontransforming strains, should they exist in nature, have been unavailable. To assay for oropharyngeal virus which has not first been selected for its transformation potential by passage in lymphocyte culture, we employed the polymerase chain reaction (PCR) procedure to amplify, up to a billion fold, selected segments of the EBV genome (3). With this approach we have detected EBV in throat washings of four healthy seronegative adults, one of which is discussed here. Biologic assays and direct PCR analysis raise the posssibility of a deletion in the EBV nuclear antigen 2 (EBNA 2) encoding sequence.