Prevention of cytomegalovirus disease.

Cytomegalovirus (CMV) disease is a significant cause of morbidity in allogeneic bone-marrow and solid-organ transplant recipients. Because of this, a number of strategies to prevent this disease have been attempted, many of which were investigated before the approval of agents that are effective in treatment. However, in bone-marrow transplantation, treatment of established disease, particularly CMV pneumonitis, carries a high mortality rate despite appropriate management. A patient-survival benefit has been shown for preemptive therapy with ganciclovir initiated on the basis of a positive CMV surveillance culture from any site before post-transplant day 100, and this should be considered the current standard of care. Among solid-organ transplant recipients, no clear standard of care has emerged, and for most patients, the basic question of whether prophylaxis is more beneficial than treatment of symptomatic infection goes unanswered.