Use of restriction enzymes to investigate the source of a primary cytomegalovirus infection in a pediatric nurse.

The risk of transmission of cytomegalovirus (CMV) infection from congenitally infected infants to nonimmune medical attendants is unknown. The case of a CMV-seronegative, pregnant nurse who seroconverted after caring for an infant with symptomatic CMV infection is reported. She elected to be aborted and the fetal tissue contained CMV. Isolates from the nurse, the fetal tissue, and the infant to whom the nurse was exposed were examined for genetic relatedness by restriction enzyme analysis. As expected, the isolates from the nurse and the fetal tissue were identical. However, the virus isolated from the symptomatic infant was different from the strain infecting the nurse. These data indicate that the nurse acquired her infection from a source other than the index infant, either within the hospital or within the community.