Cytomegalovirus blood reactivation in COVID-19 critically ill patients: risk factors and impact on mortality.

Purpose: Cytomegalovirus (CMV) reactivation in immunocompetent critically ill patients is common and relates to a worsening outcome. In this large observational study, we evaluated the incidence and the risk factors associated with CMV reactivation and its effects on mortality in a large cohort of COVID-19 patients admitted to the intensive care unit (ICU). Methods: Consecutive patients with confirmed SARS-CoV-2 infection and acute respiratory distress syndrome admitted to three ICUs from February 2020 to July 2021 were included. The patients were screened at ICU admission and once or twice per week for quantitative CMV-DNAemia in the blood. The risk factors associated with CMV blood reactivation and its association with mortality were estimated by adjusted Cox proportional hazards regression models. Results: CMV blood reactivation was observed in 88 patients (20,4%) of the 431 patients studied. SAPS II score (HR 1,031, 95% CI 1,010-1,053, p=0,006), platelet count (HR 0,0996, 95% CI 0,993-0,999, p=0,004), invasive mechanical ventilation (HR 2,611, 95% CI 1,223-5,571, p=0,013) and secondary bacterial infection (HR 5,041; 95% CI 2,852-8,911, p<0,0001) during ICU stay were related to CMV reactivation. Hospital mortality was higher in patients with (67,0%) than in patients without (24,5%) CMV reactivation but the adjusted analysis did not confirm this association (HR 1,141, 95% CI 0,757-1,721, p=0,528). Conclusion: The severity of illness and the occurrence of secondary bacterial infections were associated with an increased risk of CMV blood reactivation, which, however, does not seem to influence the outcome of COVID-19 ICU patients independently.