[New lights on infectious mononucleosis]

This review focuses on recent studies that shed new lights on infectious mononucleosis (IM). The major transmission of Epstein-Barr virus (EBV) via saliva is opposed to the possibility of sexual transmission of EBV in developed countries. Multiple infections with different LMP-1 EBV genotypes are frequently observed during IM but with unclear significance. The strict lymphotropism of the virus during primary EBV infection is questioned. Prolonged high EBV-load in saliva is clearly demonstrated during IM and could be explained by a different immune response in tonsil versus blood. Benign and severe IM are also explained by the variability of the immune response. Correlations between severity of IM and high viral load in blood are controversial. A relationship between IM and Hodgkin's disease is suggested by several epidemiological studies. Despite potential new antiviral targets and preliminary human vaccine trials, the lack of curative or preventive treatment against IM is pointed out.