Like Caucasians, Hispanic and Black individuals who have had mononucleosis, commonly known as mono, which is caused by Epstein-Barr virus, may have an increased risk of multiple sclerosis.
 
While being infected at a young age with Epstein-Barr virus generally causes few, if any, symptoms, delayed exposure into adolescence or adulthood can cause mono with symptoms that can be quite severe. For the study, researchers recruited 1,090 African American, Hispanic and Caucasian participants, during a three-year period, with each group having a near balance of healthy people to people with MS or its precursor – clinically isolated syndrome. Participants had blood tests to check for the Epstein-Barr virus antibody and were asked whether they had ever had mono.
 
Researchers found that independent of other factors that could affect MS risk, such as sex, age, smoking and genetic ancestry, the risk of MS for those who had mono was higher than for those who had not. African Americans who had mono were more than four times more likely to develop MS than those who had not, Hispanics were nearly four times more likely and whites were two times more likely.
 
One possible limitation of the study is that the control group may not represent the population overall.
 
The study was published in the online issue of Neurology.