Reactivation of latent human cytomegaloviral infection in critically ill patients

BACKGROUND & OBJECTIVES: Human cytomegalovirus (HCMV) is a frequent participant in the infectious process in critically ill patients. This study aimed to determine the incidence of HCMV reactivation in critically ill patients and estimate the clinical effect of reactivation on the course of the pathological process. METHODS: To determine the incidence of HCMV reactivation, plasma and sputum samples were collected from 82 critically ill patients. HCMV reactivation was determined by quantitative PCR together with the presence of circulating HCMV IgG in the plasma. The statistical analysis of clinical data employed methods of descriptive (median with 95% confidence interval; minimum and maximum values, interquartile range) and nonparametric statistics [Mann-Whitney U test, odds ratio (OR), Kaplan–Meier survival analysis]. RESULTS: HCMV reactivation was found in 36.6 per cent of cases. An association between the presence of sepsis and the development of HCMV reactivation (P<0.001), as well as higher HCMV viral loads in septic patients, was found. There was also an association between the presence of HCMV DNA and the subsequent development of sepsis (OR=1.504). The involvement of HCMV in the emerging immunological shifts manifested by a decrease in CD8+ T-lymphocytes (P=0.01) and an increase in the immunoregulatory index (P=0.03) was found. INTERPRETATION & CONCLUSIONS: HCMV reactivation can influence the course of bacterial pathology with a deteriorating effect on such groups of patients. Monitoring the viral load of latent HCMV can be helpful in the assessment of the host immune status, the course of the pathological process, and its clinical prognosis.