Based on five studies where CMV infection was assessed at least weekly, the mean (or median) time to onset of CMV infection ranged from 4 to 28 days [7, 8, 10, 11, 16] . Among studies where PCR was used, the mean (or median) time ranged from 4 to 12 days [7, 10, 11] . A PCR assay seems to help diagnose CMV infection earlier than the antigenemia assay. In a study that used both methods for the diagnosis of CMV infection, the median time between onset of sepsis and CMV infection determined by PCR and antigenemia were four days (range 1 to 23 days) and 11 days (range 1 to 23 days), respectively [7] .