Clinical findings - 3 or more of the following:
(1) prolonged or recurrent episodes of fever and/or exanthem
(2) hepatosplenomegaly and/or lymphadenopathy
(3) chronic hepatitis and/or interstitial pneumonitis
(4) pancytopenia and/or virus-associated hemophagocytic syndrome
(5) hypersensitivity to mosquito bite, granular lymphocyte proliferative disease, and/or increased proportion of HLA-DR-positive T cells
Laboratory findings of elevated titers of serum antibodies against antigens of the viral replicative cycle: one or more of the following:
(1) anti-viral capsid antigen IgG (anti-VCA IgG): titer > 1:640
(2) anti-viral capsid antigen IgA (anti-VCA IgA): titer > 1:20
(3) anti-early antigen IgG (anti-EA IgG): titer > 1:160
The presence of both the clinical and laboratory findings is diagnostic for chronic active EBV infection.
NOTE: Although not given by the authors, I would imagine that the presence of 2 of the clinical findings plus the laboratory findings would qualify as a probable diagnosis.
Other findings:
(1) elevated levels of Epstein-Barr nuclear antigen
(2) high copy numbers of the EBV genome
