Overview
Clinical Pattern and Mechanism
Epstein Barr virus (EBV, or human herpesvirus 4) infects B lymphocytes.
Epstein-Barr virus (EBV, or human herpesvirus 4) infects B lymphocytes. The most recognizable findings of infectious mononucleosis are caused less by direct tissue destruction than by the vigorous immune response to those infected cells. Activated T lymphocytes expand in response, producing the characteristic atypical lymphocytes seen in peripheral blood. The bedside pattern is fever, marked pharyngitis, posterior cervical lymphadenopathy, and fatigue. Tonsils may be enlarged and covered with exudate, which can resemble streptococcal pharyngitis. The spleen may enlarge as lymphoid tissue becomes congested and infiltrated. Splenomegaly can be present even when the abdominal examination is not dramatic, so feeling well does not establish that the spleen has returned to normal. EBV usually spreads through saliva, including kissing or sharing drinks, utensils, or toothbrushes. After primary infection, the virus remains latent in memory B lymphocytes and may be shed intermittently in saliva. This explains why transmission cannot be prevented by isolating a patient only during the period of obvious symptoms. Most illness is self-limited, but the complications change nursing priorities. An enlarged spleen can rupture spontaneously or after relatively minor trauma....
