Presence of human cytomegalovirus DNA in blood of patients with community-acquired pneumonia.

After a primary infection, human cytomegalovirus (HCMV) remains latent in certain human cells. Different stimuli, including immune deficiency and severe infection, can trigger the reactivation of latent HCMV infection. In the last decade, the role of the reactivation in immunocompetent patients with serious illness has been intensely studied; however, the knowledge of the potential role of moderately severe infections on HCMV dynamics is limited. In the prospective study, 80 HCMV-seropositive, immunocompetent adult patients with community-acquired pneumonia (CAP), treated outside the intensive care unit (ICU), were monitored with real-time polymerase chain reaction (PCR) for the presence of HCMV DNA. Detection of HCMV DNA in whole blood and/or plasma was interpreted as reactivation of latent HCMV infection. HCMV DNA was detected in 6 of 80 (7.5%) patients. All HCMV DNA-positive patients were classified according to the pneumonia severity index (PSI) as high-risk classes IV or V; thus, HCMV DNAaemia rate within these two PSI classes was 16.7%. All of the patients had positive whole blood samples, whereas plasma samples were positive in a single patient. We did not detect any significant differences comparing six patients with proven HCMV DNAaemia and 74 patients in whom HCMV DNAaemia was not demonstrated regarding the levels of inflammatory parameters on admission, length of treatment with supplemental oxygen, and length of hospital stay. In conclusion, the finding of HCMV DNAaemia in patients with CAP treated outside the ICU is a rare event and occurs only in patients with PSI classes designating more severe pneumonia.