Use of CMV-DNA Extraction from Dried Blood Spots to Retrospectively Diagnose Congenital Cytomegalovirus infection

Inability to confirm the diagnosis of congenita! cytomegalovirus (CMV) infection beyond the neonata) period has precluded comprehensive definition of illness and diagnosis in the individuai patient. Following reports of detection of CMV-DNA by PCR in semm of congenitally infected infants and successful extraction of CMV-DNA from dried blood spots (DBS), we submitted DBS from 3 infants, referred for evaluation for possible congenita! infection, at the ages of 9 months, 12 weeks and 9 weeks. Aim: To examine the use of CMV-DNA extraction from DBS in confirming retrospectively congenita! infection. Methods: DBS on Guthrie cards (taken on day 3 oflife) of the three infants, were retrieved and tested for CMV by DNA-PCR, using published methods (Clin Diagn Virol 1996;6:27).Results: Urine cultures for CMV, taken initially at referral, were positive in all patients. Clinica; data included unremarkable pregnancy, delivery and newborn examination in all infants. At referral, alt had developmental delay, patients 1+2 had microcephaly, patient 3 had hypertonicity. Hearing loss was found in patients 1+2. Cranial CT showed white matter changes and calcifications in all 3 infants. DBS for CMV were positive in 4 tests in patients 1+2 and negative in 4 tests in patient 3. Further metabolic investigation was abnormal in patient 3.Conclusions: Patients 1+2 had congenita! CMV infection while patient 3 acquired the infection beyond the neonata! period. Results are encouraging and demonstrate the feasibility of this methodology. Further studies are required to determine its sensitivity and specificity