AN OUTBREAK OF ENTEROBACTER-HORMAECHEI INFECTION AND COLONIZATION IN AN INTENSIVE-CARE NURSERY

Enterobacter hormaechei was first identified as a unique species in 19 89. Between 29 November 1992 and 17 March 1993, an outbreak of E. horm aechei occurred among premature infants in the intensive care nursery (ICN) at The Hospital of the University of Pennsylvania. The 10 infant s whose cultures were positive for E. hormaechei (six were infected an d four were colonized) had a lower median estimated gestational age an d birth weight than did other ICN infants; other risk factors for infe ction or colonization with E. hormaechei were not identified. Cultures from three isolettes and a doorknob in the ICN were positive for E. h ormaechei. Pulsed-field gel electrophoresis of isolates from six patie nts and two isolettes were identical. Observations of health care work ers revealed breaks in infection control techniques that may have allo wed transmission of this organism. We found that E. hormaechei is a no socomial pathogen that can infect vulnerable hospitalized patients and that can be transmitted from patient to patient when infection contro l techniques are inadequate.