Having infectious mononucleosis/glandular fever increases one's risk of coming down with ME/CFS immediately and multiple sclerosis later in life. IM is usually caused by a herpesvirus called Epstein-Barr virus. A recent study suggests that herpesviruses can vastly alter immune functioning. Could a bout of IM/glandular fever set you up for a fall? Let us know if you were ever diagnosed with IM/glandular fever and how it turned out in the poll below.