In this study, plasma (stored frozen at -80°C within 48 hours after collection, without any additional RNA preservative) from residual blood samples of 22 immunocompromised patients experiencing HCMV DNAemia episodes in whole blood (WB) were retrospectively analysed. HCMV infection was monitored at the Fondazione IRCCS Policlinico San Matteo, Pavia, by weekly determination of WB DNAemia. Pre-emptive antiviral therapy with GCV or VGCV was administered in 20 episodes of WB DNAemia of 18 patients (two of whom had two different episodes of HCMV DNAemia), while four patients had a transient, self-resolving episode of WB DNAemia that did not require pre-emptive therapy (Table 1).