Abstract
Recent developments in molecular biology have allowed precise quantitative analysis of herpesvirus DNA in many biological fluids. Th is paper reviews the clinical utility of performing quantitative polymerase chain reaction testing for herpesviruses. In particular, the assessment of the cytomegalovirus (CMV) DNA load in blood with regard to the development of CMV disease in immunocompromised patients is discussed in greater detail. Relevant information exists to support measuring the CMV burden in the blood of AIDS and transplant patients for diagnostic and treatment monitoring purposes, and, to a lesser extent, to envision the monitoring of the circulating Epstein-Barr virus load for the prevention of pose-transplant lymphoproliferative disorders. On the ocher hand, there are controversial data on the clinical utility of measuring the herpes simplex virus (HSV) load in cerebrospinal fluid of patients with HSV encephalitis and on the relationship between the human herpesvirus 8 DNA load in diverse biological fluids and the presence of Kaposi's sarcoma. There is a paucity of information about the clinical impact of quantifying the other human herpesviruses (varicella-zoster virus, and human herpesviruses 6 and 7).