Epstein-Barr virus reactivation in critically ill immunocompetent patients

Herpes viruses can be reactivated among immunocompetent patients in intensive care unit (ICU). Cytomegalovirus (CMV) and herpes simplex virus (HSV) have been the most studied. We hypothesized that Epstein-Barr virus (EBV) could also be reactivated in immunocompetent patients during their stay in ICU and that this would be associated with morbidity and mortality.

This prospective observational study included 90 patients with an ICU stay of ≥ 5 days. CMV and HSV were considered when clinically suspected and DNA was researched in blood or bronchoalveolar lavage (BAL). EBV DNA viral quantification was performed in the blood samples.

EBV DNA was detected in blood of 61 patients (median length for positivity of 7.5 days). CMV DNA was detected in blood of 16 patients (median length for positivity of 13.5 days) and BAL of 6 patients. HSV1 DNA was detected in the BAL of 28 patients (median length for positivity of 7.5 days). Nineteen patients had no viral reactivation, 1 experienced only CMV, 32 had only EBV, 5 had only HSV, 6 had EBV and CMV, 14 had EBV and HSV, and 9 patients reactivated three viruses. Mortality was higher among patients with EBV reactivation (33/61 vs. 7/25, p = 0.02). Length of stay (21 vs. 10 days, p < 0.001) and length of mechanical ventilation (15 vs. 7 days, p < 0.001) were higher among patients with EBV reactivation.

This study shows that EBV DNA is detected in blood of diverse ICU patients with ≥ 5 days of stay and that it is associated with morbidity and mortality. Larger dynamic prospective studies are needed to correlate viral reactivation with immune system evolution during ICU stay and to determine the role of polyviral reactivations.