In a study a 6-year-old boy was experienced aplastic anemia two months after the onset of acute hepatitis associated with echovirus-3 [33] . As idiopathic aplastic anemia is associated with the increased level of secretion of INF-γ and TNF-α from T cells which inhibit the hematopoietic cell proliferation [39] , similar increased level of serum INF-γ and TNF-α was found in the patient four weeks after the onset of aplastic anemia [33] . Similarly varying degrees of cytopenia has been related to the HIV infection and severe aplastic anemic conditions develop after subsequent attack of HSV-6 [17, 40] .