Background: During a meticillin-resistant Staphylococcus aureus contact tracing and screening investigation, two borderline oxacillin-resistant Staphylococcus aureus (BORSA)positive screening... Show moreBackground: During a meticillin-resistant Staphylococcus aureus contact tracing and screening investigation, two borderline oxacillin-resistant Staphylococcus aureus (BORSA)positive screening cultures were encountered among neonatal intensive care unit (NICU) healthcare workers (HCWs). This finding led to further investigations. Aim: To assess the likelihood of an outbreak with direct transmission among HCWs. Methods: An infection control team was initiated after the discovery. The team initiated additional infection control measures and evaluated new findings. All NICUs and paediatric ward HCWs were screened for BORSA carriage, and a prospective BORSA seven-week monitoring period for patients was observed. To assess the likelihood of an outbreak with direct transmission among HCWs, the BORSA isolates were analysed using augmented fragment length polymorphism and whole-genome sequencing (WGS). Findings: Positive HCWs were prohibited from clinical work while awaiting the results from the screening programme. In all, 127 NICU and 77 general paediatric ward HCWs were screened for BORSA carriage; five HCWs were BORSA positive. Seventy-two patients were screened during the seven-week period yielding a total of 138 cultures, ranging from one to nine cultures per patient. No spread from HCWs to patients occurred, and the BORSA screening programme was discontinued. WGS analysis with core genome multi-locus sequence typing of all five BORSA strains showed relatedness between two NICU strains. Conclusion: During a seven-week period, no transmission from BORSA-positive HCWs to neonates was observed in either screening or clinical cultures. More vigilance and experience is needed to design adequate evidence-based interventions in the future for this vulnerable population. (c) 2020 Published by Elsevier Ltd on behalf of The Healthcare Infection Society. Show less
Introduction. Staphylococcus aureus is a major cause of hospital infections worldwide. Awareness towards methicillin-resistant S. aureus (MRSA) infections is high but attention towards borderline... Show moreIntroduction. Staphylococcus aureus is a major cause of hospital infections worldwide. Awareness towards methicillin-resistant S. aureus (MRSA) infections is high but attention towards borderline oxacillin-resistant S. aureus (BORSA) is limited, possibly due to an underestimated clinical relevance, presumption of low incidence and diagnostic limitations. Gap statement. BORSA surveillance has not been routinely implemented, and thus consensus with regard to a definition and infection control measures is lacking. Aim. Our goals were to investigate the occurrence, molecular characteristics and clinical manifestations of BORSA infections in the hospital setting. Methodology. Following an increased incidence in 2016, BORSA cases in 2014/2016 (in our institution) were more specifically evaluated. Medical records were reviewed to investigate epidemiological links, clinical characteristics and outcomes. Resistance and virulence markers were assessed by whole genome sequencing (WGS). Conventional methods: amplified fragment length polymorphism (AFLP) ; multilocus sequence typing (MLST) and multiple locus variable-number tandem repeat analysis (MLVA) were compared with core genome MLST (cgMLST) and whole-genome single nucleotide polymorphism (wgSNP) analysis to confirm genetic clusters. Results. From 2009 to 2013, BORSA comprised 0.1 % of all clinical S. aureus strains. In 2016, the incidence was six -fold higher in comparison to the baseline. Whole-genome SNP and cgMLST confirmed two BORSA clusters among patients with dermatological conditions. Patients with BORSA presented with skin infections, and one case developed a severe invasive infection with a fatal outcome. Infection control measures successfully prevented further transmission in both clusters. WGS findings showed that BORSA strains carried multiple resistance and virulence genes with increased pathogenic potential. Conclusion. WGS and cgMLST effectively characterized and confirmed BORSA clusters among at -risk patients with clinical manifestations ranging from mild skin infections to life-threatening bacteraemia. Clinical awareness and active monitoring are therefore warranted for the timely implementation of infection control measures to prevent BORSA transmission in high -risk patients. Show less
