[Epstein-Barr virus (EBV)]

Epstein-Barr virus (EBV) is a B-lymphotropic human herpesvirus that infects the vast majority of the world's population; it establishes lifelong latency in the infected host. The virus enters through the oropharyngeal mucus and replicates in epithelial cells. The infiltrating B lymphocytes become infected and normal resting B cells activated by the virus result in immortalised B cell populations. This growth program utilises all of the latent genes and proteins. Following primary infection, the virus is found in saliva for weeks and chronic shedding participates in transmitting the infection from person to person through intimate kissing contact. EBV causes infectious mononucleosis, leads to EBV-induced malignant B-cell lymphoma in immunosuppressed patients, and is implicated in the pathogenesis of several cancers in the immunocompetent. Laboratory confirmation of infectious mononucleosis employing serological testing is generally required. Chronic infection and reactivation however need additional investigations such as nucleic acids testing. Quantitative polymerase chain reaction is now used as the major marker in B-cell proliferations either for assessing risk factors or for evaluating the efficacy of anti-EBV treatments.