An outbreak of Acinetobacter calcoaceticus infection in a neonatal care unit

Between January and December 1988, 383 neonates were admitted to our neonatal intensive care unit. 1,991 swabs and blood cultures were tested bacteriologically. Among them 90 specimens obtained from 41 patients were positive for Acinetobacter calcoaceticus. During this period we discovered and treated three cases with A. calcoaceticus sepsis. Three additional cases had blood cultures positive for this bacterium without demonstrating any clinical signs of infection. There is good evidence that contaminated warm air humidifiers were the source of infection. A review of microbiological data for several months preceding the outbreak showed a definite increase in the presence of A. calcoaceticus. The affected neonates required specific antibiotic therapy and intensive care. All of them survived. Conditions favoring the spread of these generally non-pathogenic bacteria and modes of preventive measures are discussed. The necessity of continuous bacteriological surveillance and careful disinfection of intensive care equipment is emphasized.