Nosocomial outbreak caused by Serratia marcescens in a neonatology intensive care unit in a regional hospital. Analysis and improvement proposals

Objectives: Serratia marcescens may cause nosocomial outbreaks in neonatal intensive care units. We describe an outbreak of Serratia marcescens in a neonatal intensive care unit and propose additional prevention and control recommendations. Methods: Between March 2019 and January 2020, samples were taken from patients in the neonatal intensive care unit (rectal, pharyngeal, axillary and other locations) and from 15 taps and their sinks. Control measures were implemented including thorough cleaning of incubators, health education to staff and neonates' relatives, and use of single -dose containers. PFGE was performed in 19 isolates from patients and in 5 environmental samples. Results: From the first case in March 2019 to the detection of the outbreak, a month elapsed. Finally, 20 patients were infected and 5 colonized. Eighty percent of infected neonates had conjunctivitis, 25% bacteremia, 15% pneumonia, 5% wound infection, and 5% urinary tract infection. Six neonates had 2 foci of infection. Among the 19 isolates studied, 18 presented the same pulsotype and only one of the isolates from the sinkhole showed a clonal relationship with those of the outbreak. Initial measures established were ineffective to control the outbreak and were implemented with exhaustive cleaning, use of individual eye drops, environmental sampling and changing sinks. Conclusion: This outbreak presented a high number of neonates affected due to its late detection and torpid evolution. The microorganisms isolated from the neonates were related to an environmental isolate. Additional prevention and control measures are proposed, including routine weekly microbiological sampling. (c) 2023 Sociedad Espa & ntilde;ola de Enfermedades Infecciosas y Microbiolog & iacute;a Cl & iacute;nica. Published by Elsevier Espa & ntilde;a, S.L.U. All rights reserved.