What Screenings Are Done For Infectious Agents Before Processing Gamunex?

What specific screenings are done for infectious agents before processing Gamunex; specifically is screening for antibody to Hepatitis B core antigen included? A patient was tested and found to be positive for antibody to Hep B core antigen and this patient is on immunosuppressives. This patient has no identifiable risk factors for prior Hep B infection; I know the processing of Gamunex should inactivate any known viruses and I suspect that the positive test is from the gamunex itself. I am the infectious diseases consultant at Children s Hospital at Montefiore.