New name and identity for mysterious Epstein-Barr syndrome.

New name and identity for mysterious Epstein-barr syndrome

Faced with confusion and controversy about the definition and cause of chronic Epstein-Barr virus syndrome, a group of 16 physicians and researchers from around the United States has published a working definition of the mononucleosis-like illness, renaming it chronic fatigue syndrome. By doing so they hope to begin finding out if this is one disease or many diseases and what might be causing it.

In 1985 medical researchers first made a case for a connection between Epstein-Barr virus and a mysterious collection of symptoms -- including fever and persistent fatigue -- which seemed unconnected to any specific illness. Since then, extensive media coverage has led to wide interest in the virus, even as physicians and researchers have become more skeptical about whether the syndrome is a discrete disease. Some doctors have called it a "fad" disease.

"A lot of people were diagnosed in error," says one of the researchers, medical epidemiologist Gary Holmes of the Centers for Disease Control in Atlanta. Doctors were mistakenly under the impression that a diagnosis of Epstein-Barr syndrome required only a non-specific illness and a positive test for the virus, says Holmes.

The authors of the new definition, which is published in the March ANNALS OF INTERNAL MEDICINE, point out that while there seems to be some correlation between the syndrome and Epstein-Barr virus, the virus is not found in all people diagnosed with the syndrome, and there are equally strong or stronger associations between the syndrome and other viruses, such as herpes simplex and measles viruses.

Furthermore, an estimated 90 percent of the adult U.S. population harbors the Epstein-Barr virus and most of these never become ill, according to psychiatrist Leonard Zegans of the University of California School of Medicine in San Francisco, a coauthor of the report. "there's a real question about whether this has an organic basis or whether it's a variant of depression," he says.

The working definition states that a diagnosis of chronic fatigue syndrome can be made only when the physician notes persistent fatigue over six months. The patinet should have no prior history of these sorts of symptoms, and the physician must rule out infections, parasites, endocrine diseases, AIDS and other diseases that might cause similar symptoms.

In addition to these major criteria, the patient must report at least eight of 11 symptoms that persist or recur over six months: a mild fever, a sore throat, painful lymph nodes, general muscle weakness, muscle discomfort, fatigue for more than 24 hours after light exercise, headaches, joint pain without swelling, depression or other neuropsychological complaints, sleep distrubances and development of the initial symptoms over a few hours to a few days. The diagnosis can also be made if the patient reports six of the 11 symptoms and the physician observes at least tow of three physical signs: a low-grade fever, inflammation of the pharynx and noticeably swollen lymph nodes.

The definition is intended mostly as a restrictive diagnostic tool for researchers so that they can study only the most clear-cut cases and maximize the chance of finding a causative agent.

"In order to identify a disease agent you have to have a clear clinical syndrome," says Zegans. "Once you answer the question of whether there is a phenomenon, then you can begin to ask the question of what causes the phenomenon."