<qa>  What is the name of the virus that causes a flu like illness?In normal people, the Epstein-Barr EB virus infection causes a flu like illness and usually gets better when the immune system controls the infection. The virus, however, remains hidden in the body for life. After a transplant, while the new immune system is growing back, the EB virus can come out and infect cells and cause them to grow in an uncontrolled manner. Patients can develop fevers, swollen lymph nodes and damage to other organs such as kidneys and lungs. This infection acts like a cancer because the cells infected with EB virus grow very quickly and there is no known effective treatment. This sort of infection will occur in between 10-30 of patients receiving a transplant from a donor who is not a perfect match, and has been fatal in nearly all these cases. 