Gram-negative sepsis in neonates: a nursery outbreak due to hand carriage of Citrobacter diversus.

An outbreak of Citrobacter diversus infections occurred in a newborn nursery at a 350-bed community hospital during September and October 1978. Two infants developed sepsis and meningitis and nine additional infants had asymptomatic umbilical colonization. These infants did not differ from control, noncolonized infants with respect to numerous clinical and environmental variables. Surveillance cultures failed to implicate an environmental source for the Citrobacter. However, cultures of nursery personnel identified a hand-carrier whose removal eliminated neonatal colonization with C diversus and decreased the number of isolates of certain other enteric bacteria found on umbilical stumps. Factors implicated in the perpetuation of the carrier state in this nurse included marked dermatitis from repeated hand washing and hand care practices involving the overnight use of plastic gloves and nutritive hand cream. The mode of transmission within the nursery appeared to be from nurse's hands to infant's umbilicus. Use of triple dye on umbilical stumps and chlorhexidine hand washing preparations did not eliminate this cycle. Surgical manipulation of colonized umbilical stumps may have been responsible for illness in two infants.