Cytomegalovirus DNA detection in sera from patients with active cytomegalovirus infections

Using a specific and sensitive polymerase chain reaction method, we detected reliably the presence of human cytomegalovirus (HCMV) DNA directly in serum samples collected at an early stage of HCMV infection, even before immunoglobulin M (IgM) antibodies were measurable. HCMV DNA was detected in serum from all patients with active HCMV infection; in 91% of these patients, HCMV DNA was found in the acute-phase serum. In 13 of 44 patients, HCMV DNA was found in serum before HCMV-specific IgM. For four kidney transplant recipients, the occurrence of HCMV DNA in serum, virus isolation from urine and leukocytes, and HCMV IgG and IgM serology were determined. We found a correlation between HCMV DNA in serum and positive virus isolation from leukocytes. In three of five congenitally infected infants, HCMV DNA and HCMV IgM were detected in the same sample. Two other infants were HCMV DNA positive, although no HCMV IgM antibodies were measurable. HCMV was found in urine from these infants either by virus isolation or with the polymerase chain reaction. Serum from one of the 22 healthy HCMV-seropositive blood donors was HCMV polymerase chain reaction positive.