Israel Medical Association Journal

Background: Methicillin-resistant Staphylococcus aureus (MRSA) has emerged as a challenging nosocomial pathogen in the last 50 years.

Objectives: To describe an investigation and containment of an MRSA outbreak in a neonatal intensive care unit (NICU).

Methods: Our NICU is a 25-bed level III unit. Almost 540 neonates are admitted yearly. The index case was an 8 day old term baby. MRSA was isolated from his conjunctiva. Immediate infection control measures were instituted, including separation of MRSA+ carriers, strict isolation, separate nursing teams, and screening of all infants for MRSA. Healthcare workers and parents of positive cases were screened and re-educated in infection control measures. New admissions were accepted to a clean room and visiting was restricted. MRSA isolates were collected for molecular testing.

Results: MRSA was isolated from five infants by nasal and rectal swabs, including the index case. Screening of healthcare workers and families was negative. Two MRSA+ patients already known in the pediatric intensive care unit (PICU) located near the NICU were suspected of being the source. All NICU isolates were identical by pulsed-field gel electrophoresis but were different from the two PICU isolates. The NICU and one of the PICU isolates were defined as ST-5 strain by multilocus sequence typing. One PICU isolate was ST-627. All NICU isolates were Panton–Valentine leukocidin negative and SCCmec type IV. No further cases were detected, and no active infections occurred.

Conclusions: A strict infection control policy and active screening are essential in aborting outbreaks of MRSA in the NICU.

Background: Extended-spectrum beta-lactamase (ESBL) production is the most common antimicrobial resistance mechanism in the neonatal intensive care unit (NICU), with colonization and blood stream infections being a major threat to this population. Since 2013, all NICU admissions at our facility were screened twice weekly for ESBL colonization.

Objectives: To determine independent risk factors for colonization of infants with ESBL-producing bacteria in the NICU.

Methods: A retrospective case study of ESBL-colonized infants vs. controls (matched by date of birth and gestational age) was conducted in the NICU of Soroka University Medical Center, Israel, between 2013 and 2014. Epidemiological, laboratory, and clinical data were extracted from medical files. Univariable and multivariable analyses were used to assess associations between ESBL colonization and possible clinical risk factors.

Results: Of 639 admissions during the study period, 87 were found to be ESBL-colonized (case infants) and were matched to 87 controls. Five case infants became infected (5.7%) with ESBL strains. Klebsiella pneumoniae was the most common isolated bacteria. The mean time from admission to colonization was 15 days. Univariable analysis showed an association of male gender and highest Apgar score at 1 and 5 minutes with ESBL colonization (P < 0.05). Multivariable analysis yielded only a possible association of higher Apgar score at 1 and 5 minutes (hazard ratio [HR] 1.515, 95% confidence interval [95%CI] 0.993-2.314; HR 1.603, 95%CI 0.958–2.682, respectively) with ESBL colonization.

Conclusions: Future studies should focus on maternal colonization and possible strategies for preventing vertical transmission of ESBL strains to high-risk neonates.