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Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
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Epstein-Barr virus (EBV) VCA-IgG 1 :80 and EBV antibody to early antigen EA1 :320 suggest which one of the following diseases?
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The correct answer is  Infectious mononucleosis (IM) may be suspected clinically but it is confirmed serologically. The heterophil antibody test, however, may be negative in up to 15% of adults and 35 to 40% of children. Because IM is caused by Epstein-Barr virus (EBV), a specific test for viral capsid antigen (VCA) of EBV is indicated when heterophil tests are negative. Acute IM is characterized by a VCA-IgM titer, and no VCA-IgG antibody or EBNA. Chronic EBV disease causes elevated VCA-IgG titers as well as high EA antibody titers.