Table 2.

Comparison of current CMV prevention strategies

Strategy	Prophylaxis	Preemptive Therapy
Principle	Antivirals administered to all at-risk patients for a defined period of time following transplantation	CMV DNA test (at least once weekly) Antiviral therapy started when viral load exceeds a certain threshold
Advantages	Effectively prevents early CMV reactivation	Reduced medication cost Lower risk of drug toxicity Allows immune reconstitution
Disadvantages	High rates of medication side effects Increased drug cost Risk for delayed-onset CMV disease	Does not prevent early CMV reactivation Escape CMV infections (not detected by weekly CMV NAT) Burden, logistics and cost of weekly surveillance labs

Abbreviations: CMV, Cytomegalovirus; NAT, Nucleic Amplification Test.