Successful treatment of human herpesvirus-6 encephalitis after bone marrowtransplantation

We report two cases of human herpesvirus-6 (HHV-6)-associated encephalitis in patients after BMT. Both patients reported distinct neurological symptom s with disorientation, sleepiness and loss of short-term memory. Diagnosis was based on PCR analysis of the cerebrospinal fluid (CSF) positive for HHV -6 variant B-DNA. After institution of therapy with foscarnet in both cases , neurological symptoms improved and in one patient clearance of HHV-6-DNA from CSF was demonstrated. These cases show that HHV-6 infection has to be considered in patients with neurological symptoms following BMT and effecti ve treatment of HHV-6 encephalitis is possible if instituted early.