CMV syndrome is defined as a virologically confirmed illness with any of the following: fever, pneumonia, leukopenia, lymphocytosis, thrombocytopenia, serum alanine aminotranferase levels > 2.5 x normal, with or without “flu–like” manifestations of viral immunity (malaise, myalgias, arthralgias, anorexia, nausea, vomiting). Any patient presenting with any of these signs or symptoms at any time during this study will have blood, body fluid, and/or biopsy specimen sent for viral confirmation which may include any of the following studies: histology for the presence of inclusion bodies, immunofluorescence of antibody to pp65 antigen or qualitative presence of CMV genome by PCR amplification.