Experimental studies have shown that ganciclovir prevented murine CMV reactivation and the development of pulmonary fibrosis in immunocompetent mice with sepsis [42] . Two retrospective studies where small subsets of ICU patients received antiviral agents for CMV infection have yielded inconclusive results and data on the utility and efficacy of antiviral therapy for CMV in critically ill immunocompetent patients are largely lacking [17, 18] . Employment of potent antiviral therapy in all critically ill patients may be impractical, logistically infeasible, and potentially harmful given a large number of ICU patients and potential adverse effects of ganciclovir such as bone marrow suppression or teratogenicity. A more prudent approach may be to identify subgroups of patients at high risk for developing CMV infection and targeting antiviral prophylaxis towards these patients. These subgroups may include patients with sepsis, persistent fever, or those receiving transfusion. An alternative approach is to employ antiviral therapy only in those with CMV viremia. Regardless, carefully conducted clinical trials are warranted to discern the impact of antiviral agents on clinically meaningful outcomes before employing antiviral therapy or even considering routine monitoring of CMV in critically ill patients.