Epstein-Barr Virus

EBV was first discovered in 1964 by three researchers—Epstein, Achong, and Barr—while studying a form of cancer prevalent in Africa called Burkitt's lymphoma. Later, its role in IM was identified. A surge of interest in the virus has now determined that up to 95% of all adults have been infected with EBV at some stage of their lives. In seriously immunocompromised individuals and those with inherited immune system deficiencies, the virus can become chronic, resulting in "chronic Epstein-Barr virus" which is extremely serious and can be fatal.

Age and the health of the immune system play important roles in EBV-related illnesses. Infectious mononucleosis is the most common illness resulting from primary EBV infection. In young children, it often takes on mild flu-like symptoms that improve with time, or the symptoms are so mild they go unnoticed. However, ill or older people, IM can become a debilitating infection, and complications can affect almost every organ of the body, including possible rupture of the spleen. In fewer than 1% of IM cases, neurologic complications develop, and the patient can develop encephalitis, meningitis, Guillian-Barre syndrome, or other serious conditions. Very rarely, IM causes complications like aplastic anemia, thrombocytopenia (reduced numbers of platelets, the clotting factor in blood, resulting in bleeding), and granulocytopenia (severe reduction in white cells in the blood allowing the potential for "superinfection"). More commonly, however, IM causes persistent fevers; swollen and tender lymph glands in the neck, groin, and armpits; sore throat and even severe tonsillitis; and sometimes a rash. Because the sore throat is so prominent, and because it may in fact become secondarily infected with strep, some patients are treated with ampicillin. Almost all of these individuals will break out in a rash which is often mistaken for evidence of a penicillin allergy. IM is almost always accompanied by fatigue and general malaise which can be quite severe initially, but bouts of which become less severe and prolonged over several weeks or months. Inflammation of the spleen and liver are also common in IM. The spleen in particular may grow very large, and may rupture spontaneously in about 0.5% of patients.

EBV is also implicated in another immune system-related illness called chronic fatigue syndrome (CFS). In several communities throughout the world, several epidemic-type outbreaks of what became known as CFS, including one in Lake Tahoe in 1985, baffled the medical community. There have been many conflicting theories in the ongoing search for the role of EBV in CFS. Initially, EBV was thought to be the causative factor; however, following intense studies performed during an outbreak of CFS in New York in 1985, it was determined that not everyone suffering from CFS developed antibodies to EBV. In cases where several children in one family all showed the same symptoms, only thee out of four showed infection by EBV. Further studies revealed that about one-third of the individuals affected by CFS had experienced primary infection with EBV years earlier and were once again fighting the virus. This syndrome became known as "active chronic EBV infection." In the other two-thirds of CFS sufferers, EBV levels were no different to those shown by the general population. It therefore seemed inaccurate to conclude EBV was the causative agent in CFS. Because some CFS patients experience reactivation of latent EBV, while in others EBV becomes active for the first time, it is possible that the effect of CFS on the immune system allows activation and reactivation of EBV. One theory about the interrelatedness of EBV and CFS is that, rather than causing CFS, EBV may, instead, trigger it.