Epstein-Barr Virus

EBV is restricted to a very few cells in the host. Initially, the infection begins with its occupation and replication in the thin layer of tissue lining the mouth, throat, and cervix, which allow viral replication. The virus then invades the B cells, which do not facilitate the virus's replication but do permit its occupation. Infected B cells may lie dormant for long periods or start rapidly producing new cells. Once activated in this way, the B cells often produce antibodies against the virus residing in them. EBV is controlled and contained by killer cells and suppressor cells known as CD4+ T lymphocytes in the immune system. Later, certain cytotoxic (destructive) CD8+ T lymphocytes with specific action against EBV also come into play. These cells normally defend the host against the spread of EBV for the life of the host.

A healthy body usually provides effective immunity to EBV in the form of several different antibodies, but when this natural defense mechanism is weakened by factors that suppress its normal functioning—factors such as AIDS, organ transplantation, bone marrow failure, chemotherapy and other drugs used to treat malignancies, or even extended periods of lack of sleep and overexertion—EBV escape from their homes in the B cells, disseminate to other bodily tissue, and manifest in disease.

Diagnostic blood tests cannot detect the virus itself. Infection is determined by testing for the antibodies produced by the immune system to fight the virus. The level of a particular antibody—the heterophile antibody—in the blood stream is a good indicator of the intensity and stage of EBV infection. Even though EBV proliferates in the mouth and throat, cultures taken from that area to determine infection are time-consuming, cumbersome, and usually not accurate.

Treatment is primarily supportive; encouraging rest and recuperation. When spleen enlargement is present, activities may need to be restricted to avoid the complication of splenic rupture. Antibiotics should be used only to treat documented bacterial infections which complicate the course of IM. Anti-viral medications do not seem to be helpful. Steroids should only be given in the rare instance of such complications as hemolytic anemia, severely swollen tonsils which are causing airway obstruction, or platelet destruction.