Detection of EBV DNA in post-nasal space biopsy tissue from asymptomatic EBV-seropositive individuals

The association between EBV and nasopharyngeal carcinoma (NPC) has been well documented although the precise role of the virus in the genesis of the tumour is not understood. We undertook this study to examine the prevalence of EBV infection in nasopharyngeal tissue obtained from 33 healthy individuals not considered to be at risk of developing NPC. Using polymerase chain amplification (PCR) and in situ hybridization we have identified EBV DNA in 70% (23/33) of the tissues examined. Our data demonstrate that EBV is present at the site of tumour development in the low-risk population and by inference that the virus is also present before the onset of disease in the high-risk group. This survey supports the concept of NPC pathogenesis as a multifactorial process.