Aim: To time the onset of cytomegalovirus (CMV) infection in patients (n = 39) with CMV associated neonatal cholestasis by analysing CMV DNA on Guthrie cards sampled at 3 days of age.
Methods: CMV infection was diagnosed by serology/urine isolation or by CMV DNA detection (polymerase chain reaction) in liver biopsy specimens. In order to time the infection dry blood filter paper discs were punched out from stored Guthrie cards. After phenol-choloroform extraction CMV DNA was detected by nested polymerase chain reaction.
Results: All cards from control children (n = 8) with congenital CMV tested positive; none of the negative controls (n = 4) did so. Two of 39 cholestatic infants were CMV DNA positive; their mothers had serological signs compatible with infection during the second half of the pregnancy. All other cholestatic infants tested negative.
Conclusions: CMV DNA was not detected in most of the children using Guthrie cards, suggesting that infection developed at or soon after birth.