Objective: To assess the incidence, risk factors, and outcome of active cytomegalovirus (CMV) infection in nonimmunosuppressed intensive care unit (ICU) patients.

Design: Prospective epidemiologic study.

Setting: A medical ICU in a university hospital.

Patients: Two hundred forty-two nonimmunosuppressed ICU patients mechanically ventilated for >or=2 days.

Interventions: Routine pp65 antigenemia and serology for CMV were performed at admission, and then weekly. Bronchoalveolar lavage viral cultures were done when pneumonia was suspected.

Measurements and main results: Thirty-nine of the 242 ICU patients (16.1%, confidence interval 11.5% to 20.7%) developed an active CMV infection, as diagnosed by positive antigenemia (85%) and/or positive rapid viral culture in bronchoalveolar lavage (26%). Antiviral treatment was initiated in 21 (54%) patients. ICU mortality (54% vs. 37%, p = 0.082) and in-hospital mortality (59% vs. 41%, p = 0.058) were increased in patients with active CMV infection, as compared with those without active CMV infection. Active CMV infection and Simplified Acute Physiology Score II at admission were associated with ICU death on multivariate analysis. The patients with active CMV infection had longer mechanical ventilation and longer ICU stay and were significantly more prone to developing bacterial nosocomial infections (p < 0.001). Logistic regression analysis showed that prior admission to other wards (p = 0.043; odds ratio [OR], 2.49), blood transfusions (p = 0.04; OR, 3.31), enteral feeding (p = 0.005; OR, 3.00), recent corticosteroid use before ICU admission (p = 0.08; OR, 2.26), and age (p = 0.07; OR, 1.026) were associated with the occurrence of active CMV infection.

Conclusions: : Active CMV infection is common among previously healthy patients under mechanical ventilation in a medical ICU. Further studies are needed to evaluate the role of antiviral treatments to reduce both the incidence and the outcome impact of active CMV infection.