EBV Early Antigen (“EA”) Antibody IgG. This antibody may not only be detected during an active EBV infection, such as in patients with mononucleosis, but it may also be found in patients who have chronic active or reactivated EBV infection. Thus, while EBV IgG levels typically indicate antibodies have formed as a result of past exposure, EBV IgM and/or EBV EA IgG antibodies may both be used to diagnose and/or monitor a current or recurrent case of EBV.