Acquisition of donor strains of cytomegalovirus by renal-transplant recipients.

To determine the source of post-transplantation cytomegalovirus (CMV) infection in renal-transplant recipients, viral isolates were collected from pairs of patients who received kidneys from the same cadaver. Among 36 pairs of recipients, CMV viruria or viremia occurred in both members of 4 pairs and in one member of 11 pairs. Restriction-enzyme analysis of viral DNA revealed 15 distinct strains of CMV among viral isolates from these 19 patients. In all four pairs in which both members shed CMV, both recipients shed the same strain, suggesting that the virus was of donor origin. In three of these pairs, one member had been seropositive for CMV before transplantation. One seropositive recipient was simultaneously shedding two strains of CMV after transplantation; one strain was of donor origin. Two patients who had CMV viruria before receiving grafts from a seropositive donor shed a different CMV strain two months after grafting. These findings indicate that cadaveric grafts can transmit an identifiable strain of CMV to recipients, and that seropositive recipients can be reinfected by a new CMV strain from the donor after transplantation.