Background. Cytomegalovirus (CMV) represents a serious infectious complication in patients after allogenic haematopoietic stem cell transplantation. Timely initiation of the therapy at the time of incipient active CMV infection (preemptive therapy) is an important prevention of CMV disease. It is not clear, what is the best indicator of this incipient CMV infection. Methods and Results. The significance of the detection of incipient CMV infection by CMV-antigenaemia and DNA-viraemia was compared in this study. DNA-viraemia was detected by the non-nested polymerase chain reaction (PCR). The sensitivity of nested and non-nested PCR was also compared experimentally. We tested 318 blood samples for antigenaemia and DNA-viraemia. Six samples were significantly positive for PCR, no sample was significantly positive for antigenaemia. Timely initiation of therapy resulted in the rapid eradication of the incipient active CMV infection and clearance of DNA-viraemia. Conclusions. Non-nested PCR is a suitable and more reliable method for the monitoring of incipient active CMV infection and it is a good method for timely initiation of preemptive antiviral therapy.

        Key words: CMV - cytomegalovirus, preemptive therapy, PCR - polymerase chain reaction, ganciclovir, foscarnet.