Outbreak of extended spectrum beta-lactamase-producing Klebsiella pneumoniae infection in a neonatal intensive care unit related to onychomycosis in a health care worker.

Four cases of infection by extended spectrum beta-lactamase-producing Klebsiella pneumoniae occurred in the neonatal intensive care unit. Isolation, empiric therapy change and education produced no effect. Newborn weekly colonization rates were 0-18.7%. One health care worker with onychomycosis was positive for extended spectrum beta-lactamase-producing K. pneumoniae. Isolates were identical by molecular typing. Outbreak was controlled when the health care worker was excluded from the neonatal intensive care unit.