Screening of adult patients with fever of unknown origin. A prospective study on the role of primary cytomegalovirus infection

Patients and methods. In a three-year prospective survey of 135 consecutive adult patients referred for fever of unknown origin often associated with a broad spectrum of constitutional signs and symptoms, 21 (15.5%) were found to have a primary Cytomegalovirus infection. Results. In the majority of cases, this syndrome was consistently associated with altered white blood cell count, abnormal T-lymphocyte subsets and hepatosplenomegaly. On the other hand, altered white blood cell differential and serum hepatic enzymes, and constitutional signs and symptoms were absent with a rate ranging from 11.1% to 27.4% of cases, and an initial laboratory cross-reaction with anti-Epstein-Barr IgM antibodies was detected in 48.1% of episodes. Non-specific signs and symptoms were the only features in 27.4% of patients, thus confirming that this disorder may be still clinically underestimated in its real frequency, until virologic assays are carried out. An extensive and varied spectrum of subjective disturbances, sometimes of duration prolonged beyond six months involved nearly 30% of subjects, and lasted for 3-15 months after recovery of acute, primary Cytomegalovirus disease. Conclusions. In a multidiscliplinary (clinical, laboratory, and instrumental) workupt for a fever of unknown origin, a rapid recognition of a primary Cytomegalovirus disease is useful to exclude alternative diagnoses, avoid unnecessary exposure to antimicrobial agents, and reassure patients of the benign and self-limiting course of their illness.