The optimal length of treatment has not been established and relapse rates as high as 25% are common upon cessation of the antiviral agent.6 Patients with CMV disease are initially treated with intravenous ganciclovir for two or more weeks, and then with an oral agent for many weeks thereafter. Current laboratory technology allows detection of active viral replication, either through the detection of the pp65 antigen on the surface of infected leukocytes or through the use PCR amplification for the detection of viral DNA. It is however, still unclear whether the best therapeutic option is to treat until symptoms disappear or to treat until evidence of active viral replication ceases.