[Common causes of infectious mononucleosis].

Most cases of infectious mononucleosis are caused by Epstein-Barr virus (EBV). However, other rare but potentially serious etiologies need to be considered. Cytomegalovirus (CMV) and Toxoplasma gondii infections, although generally benign, can cause severe congenital infections. An acute infection by the human immunodeficiency virus (HIV) can also mimic infectious mononucleosis. Laboratory diagnostic of those infections relies primarily on the detection of specific antibodies and antigens. The interpretation of laboratory results can be impeded by cross-reactions or persistence over several months of markers of acute infection. This article reviews the most common causes of infectious mononucleosis and their diagnosis.