Both bLCV and bCMV were present in all 4 animals during immune reconstitution. Serum was obtained before transplantation (“Pre”) and at approximately 2, 4, and 6 months after transplantation and were subjected to PCR, as described in “Materials and methods.” DNA extracted from bCMV lysate (derived from bCMV-infected MRC5 cells) was used as a positive control (+) for bCMV and as a negative control (-) for bLCV. DNA extracted from bLCV-transformed B lymphoblastoid cells was used as a positive control for bLCV and a negative control for bCMV. The fact that bLCV was detected in all 4 animals before transplantation is consistent with the observation of Dittmer et al (D. Dittmer, unpublished information, April 2004, with permission), who detected bLCV in the blood of 71 of 90 normal seropositive baboons. The fact that bCMV was undetectable before transplantation and detectable at 2 to 4 months after transplantation is consistent with the expected viral reactivation, leading to increased viral load early after transplantation.