Varicella exposure in a neonatal intensive care unit: case report and control measures

Forty-six infants in a neonatal intensive care unit and 138 health care workers were exposed to a pediatric medical resident during the prodromal period and the early days of unrecognized varicella. An attempt was made to prevent an outbreak of additional cases by the institution of emergency control measures. These measures included rapid identification of varicella antibody status in exposed neonates, varicella antibody testing of health care workers with unknown or uncertain history of varicella, prompt administration of varicella zoster immune globulin to potentially susceptible persons, and cohorting neonates on the basis of exposure and antibody status. Passive maternal antibody was detected in 44 of the neonates. Of 27 health care workers who reported either a negative or an uncertain history of varicella, 26 had detectable antibody. No overt cases of varicella occurred in exposed patients or personnel.