[Difficulties in the diagnosis of prolonged fever in infants]

We report the case of an infant with cytomegalovirus (CMV) infection who developed a nosocomial sepsis of mixed etiology. Fever failed to decrease despite long-time and sustained antibiotic therapy. Treatment with an antiviral agent following the detection of CMV antibody of the IgM class resulted in clinical improvement and subsequent full recovery. We suggest that the diagnosis of CMV infection should be considered even in immunocompetent patients in whom antibiotic therapy fails.