The role of Epstein-Barr (EBV) virus in central nervous system (CNS) infections is not fully resolved. It is clearly associated with lymphoproliferative disease of immunosuppressed persons, and may cause encephalitis.

We reviewed the medical records, imaging and laboratory findings of all patients EBV DNA PCR positive in cerebrospinal fluid (CSF) during 2000 to 2009 in the Helsinki University Central Hospital.

We identified 32 patients with EBV DNA in CSF. 11 had history of allogeneic hematopoietic stem cell transplantation, 7 solid organ transplantation and 5 HIV/AIDS. 5 patients had no preceding immunodeficiency.In 8 of the cases, another pathogen was identified in CSF. These were M. tuberculosis (2), T. gondii (2), Aspergillus (1), Herpes simplex virus 1 (1), C. neoformans (1) and Human herpesvirus 6 (1). Altogether in 15/32 (47%) of the cases the clinician had a strong suspicion of cause other than EBV for the patients' CNS symptoms/findings.Of note, 7 of 11 (64%) patients with stem cell transplantation had encephalitis (univariate odds ratio 5.6; confidence Interval 1.1-27.4). Of these 6 had no other pathogen identified.

EBV DNA was often found together with other microbial findings in CSF of immunocompromised patients. EBV seems to be associated with encephalitis in stem cell transplant recipients.