Viral infection linked to multiple sclerosis

The cause of multiple sclerosis is unknown, but a new study suggests an association between infection with Epstein-Barr virus (EBV) and the risk of multiple sclerosis (MS). Multiple sclerosis is a disorder of the central nervous system resulting in abnormal hardening of the tissues in the brain and spinal cord. Symptoms include loss of vision, speech disorders, bladder abnormalities, muscle weakness, impaired balance and fatigue. It is the result of the slow destruction of myelin i.e. the thin, protective coating that insulates nerve fibers in the brain and spine. Epstein-Barr virus (EBV) infects more than 90% of the human population and can cause an illness called mononucleosis in adolescents and adults. The infection can last up to a month and causes fever, sore throat and swollen lymph glands. In a study of more than 62,000 women, the researchers at the of Harvard University in Boston, Massachusetts, found that 18 women who had blood collected prior to their diagnosis of multiple sclerosis had higher antibody levels to EBV in their blood compared to individuals without multiple sclerosis. The women did not have higher levels of antibodies to a second common virus, indicating that EBV may be linked to an increased risk of multiple sclerosis. When the investigators looked at different types of EBV antibodies, they found that one in particular seemed to increase the risk of the disease. The results support a role of EBV in the etiology of MS. However many infectious agents have been associated with multiple sclerosis, although none has been clearly linked to the disease and the search for a viral cause of multiple sclerosis continues.