Acute infectious mononucleosis-like syndrome due to infection with cytomegalovirus in immunocompetence

Background: Infections by cytomegalovirus (CMV) cause substantial morbidity and mortality in immunocompromised patients, whereas immunocompetent individuals generally experience mild disease or remain asymptomatic. Case Report: A 54-year-old immunocompetent man undergoing CMV mononucleosis and hepatitis after primary infection is reported. Symptoms were pronounced with considerably reduced general condition and sustained highly febrile temperatures. Only therapy with intravenous ganciclovir led to rapid resolution of the disease. A second case describes a 31-year-old woman who, having had contact with a CMV-infected infant, developed a mononucleosis-like illness during her pregnancy. Due to the risk of congenital CMV infection, the exclusion of CMV-caused infection or the discrimination between primary and secondary infection is of particular importance, and the second case illustrates the relevant diagnostic difficulties and pitfalls. Conclusion: As demonstrated by the two cases, even in immunocompetent patients and pregnant women CMV should be considered in the differential diagnosis of symptomatic viral infections. Particularly during pregnancy and after organ transplantation, early diagnosis and prognostic markers are necessary because of possible severe complications such as congenital CMV infection and organ transplant failure.