Outbreak of extended-spectrum beta-lactamase-producing Klebsiella pneumoniae in an intermediate-risk neonatal unit linked to onychomycosis in a healthcare worker.

Objective: To describe an outbreak of extended-spectrum beta-lactamase-producing Klebsiella pneumoniae in an intermediate-risk neonatal unit.

Methods: After the identification of the first cases, the situation was regarded as an outbreak, and basic preventive measures against nosocomial infections were strictly enforced, and possible sources of dissemination were investigated.

Results: The outbreak lasted for 6 months and affected 36 newborn infants, causing seven infections and 29 colonizations. In the first stage of the outbreak, patients developed infection, but in the second stage, they were asymptomatic and were only identified by surveillance cultures. The outbreak was controlled after the identification and treatment of the healthcare worker who had been diagnosed with onychomycosis and whose hands were contaminated with extended-spectrum beta-lactamase-producing Klebsiella pneumoniae.

Conclusions: The detection and control of occult dissemination of this multiresistant bacterium among low-risk newborn infants prevented its endemic dissemination in the neonatal unit, as well as the exposure of critically ill and susceptible patients to the infection.