Multidrug-resistant OXA-48/CTX-M-15 Klebsiella pneumoniae cluster in a COVID-19 intensive care unit: salient lessons for infection prevention and control during the COVID-19 pandemic

BACKGROUND: Wards caring for COVID-19 patients, including intensive care units (ICUs), have an important focus on preventing transmission of SARS-CoV-2 to other patients and healthcare workers. AIM: To describe an outbreak of carbapenemase-producing Enterobacterales (CPE) in a COVID-19 ICU and to discuss key infection control measures enabling prompt termination of the cluster. METHODS: CPE were isolated from clinical specimens and screening swabs from intensive care patients with COVID-19 disease and from environmental screening. Whole-genome sequencing analysis was instrumental in informing phylogenetic relationships. FINDINGS: Seven clinical isolates and one environmental carbapenemase-producing Klebsiella pneumoniae isolate – all carrying OXA-48, CTX-M-15 and outer membrane porin mutations in ompK35/ompK36 – were identified with ≤1 single nucleotide polymorphism difference, indicative of clonality. A bundle of infection control interventions including careful adherence with contact precautions and hand hygiene, twice weekly screening for multidrug-resistant organisms, strict antimicrobial stewardship, and enhanced cleaning protocols promptly terminated the outbreak. CONCLUSION: Prolonged use of personal protective equipment is common with donning and doffing stations at the ward entrance, leaving healthcare workers prone to reduced hand hygiene practices between patients. Minimizing transmission of pathogens other than SARS-CoV-2 by careful adherence to normal contact precautions including hand hygiene, even during high patient contact manoeuvres, is critical to prevent outbreaks of multidrug-resistant organisms. Appropriate antimicrobial stewardship and screening for multidrug-resistant organisms must also be maintained throughout surge periods to prevent medium-term escalation in antimicrobial resistance rates. Whole-genome sequencing is highly informative for multidrug-resistant Enterobacterales surveillance strategies.