Table 6.

Prevention of CMV disease in solid organ transplant recipients

Parameter	Commentsa
	Preemptive therapy	Antiviral prophylaxis
Strategy	Monitor patients for CMV reactivation by using highly sensitive and predictive laboratory assays (such as nucleic acid amplification tests)	Administer antiviral drug (valganciclovir) for a defined duration to all patients at risk for CMV disease (duration varies depending on the organ transplant and the risk profile of patients)
	Laboratory monitoring is performed once weekly. More frequent monitoring may be considered for patients at very high risk of CMV disease	Laboratory monitoring (NAT) for CMV reactivation is not routinely recommended for patients receiving antiviral prophylaxis
	Administer antiviral therapy (valganciclovir) only to patients who develop CMV reactivation above a predefined viral load threshold
	Monitor patients by use of CMV NAT once weekly to guide treatment duration; treatment is continued until the viral load falls to an undetectable level or below a predefined threshold
Recommended populations	CMV-seropositive (CMV D+/R+ and CMV D−/R+) heart, liver, kidney, and pancreas transplant recipients	All CMV D+/R− solid organ transplant recipients
	Considered but less preferred for CMV D+/R− heart, liver, kidney, and pancreas transplant recipients due to potential risk of breakthrough disease as a result of rapid replication dynamics	All CMV D+/R− and CMV R+ lung, intestinal, and composite tissue allograft transplant recipients
	Not recommended for lung, intestinal, and composite tissue allograft transplant recipients	All CMV-seropositive (CMV D+/R+ and CMV D−/R+) heart, liver, kidney, and pancreas transplant recipients
		All transplant patients in centers that do not have an available assay for sensitive detection of CMV reactivation
Advantages	Reduced no. of patients exposed to antiviral drugs	Prevents reactivation of other herpesviruses (i.e., herpes simplex virus, HHV-6)
	Reduced direct antiviral drug costs	Does not rely on a highly sensitive and predictive assay for CMV detection
	Reduced duration of antiviral drug use	Reduces incidence of indirect CMV effects
	Reduced toxicity related to antiviral drugs
	Lower risk of antiviral drug resistance
Disadvantages	Requires a predictive test for early identification of patients at risk of CMV disease	Prolonged antiviral drug use may lead to emergence of antiviral drug resistance
	Requires patients to comply with stringent laboratory surveillance schedule	Prolonged antiviral drug use may lead to higher incidence of adverse drug effects
	No widely accepted viral load threshold for initiation of antiviral therapy	Use of expensive drugs by all patients, including those who may not have viral reactivation
	Increased cost of diagnostic surveillance testing
	May not identify all patients at risk of CMV disease (breakthrough infection may occur in high-risk CMV D+/R− patients between scheduled weekly testing)
	CMV-selective nature does not prevent reactivation of other herpesviruses
	Prolonged duration of preemptive antiviral therapy may be associated with drug resistance

^aCMV, cytomegalovirus; HHV, human herpesvirus.