A multi-sectoral investigation of a neonatal unit outbreak of Klebsiella pneumoniae bacteraemia at a regional hospital in South Africa, 2018

Abstract

Background: Rates of healthcare-associated infections (HAIs) among babies born in developing countries are higher than those born in resource-rich countries, driven by sub-optimal infection prevention and control (IPC) practices. Following two reported deaths in neonates with carbapenem-resistant Klebsiella pneumoniae bloodstream infections (BSI), we conducted an outbreak investigation in a neonatal unit of a regional hospital in Gauteng Province. Objectives: To confirm an outbreak of K. pneumoniae BSI and assess the IPC programme within the neonatal unit. Methods and materials: We calculated total and organism-specific BSI incidence risks for culture-confirmed cases in the neonatal unit for baseline and outbreak periods. We conducted a clinical record review for a subset of cases with K. pneumoniae BSI. An IPC audit was performed in different areas of the neonatal unit. We confirmed species identification, antimicrobial susceptibility, presence of carbapenemase genes by PCR and pulsed-field gel electrophoresis (PFGE) typing of submitted clinical isolates. Results: From January 2017 to August 2018, 5262 blood cultures were submitted, of which 11% (560/5262) were positive. Of 560 positive blood cultures, 52% (n = 292) were culture-positive for organisms that are associated with HAI BSIs. Klebsiella pneumoniae comprised the largest proportion (32%; 93/292). The total incidence risk of HAI BSIs for the baseline period (January 2017–March 2018) was 6.8 cases/100 admissions, and that for the outbreak period (April-September 2018) was 10.1 cases/100 admissions. The incidence risk of K. pneumoniae BSIs for the baseline period was 1.6 cases/100 admissions, compared to 5.0 cases/100 admissions during the outbreak period. Among a subset of 12 neonates with K. pneumoniae bacteraemia, all were premature with low birth weight. The median gestational age at birth was 27 w (IQR, 26–29 w) and median birth weight was 1100 g (IQR, 880–1425 g). Twelve bloodstream and 31 colonising isolates were OXA-48 positive. PFGE analysis demonstrated that all isolates were genetically related (89% similarity). Poor IPC practices were noted, including overcrowding, sub-optimal aseptic technique and hand washing, and poor monitoring and reporting of antimicrobial use. Conclusion: Overcrowding, poor IPC practices and inadequate antimicrobial stewardship contributed to a large outbreak of BSIs caused by genetically-related carbapenemase-producing K. pneumoniae isolates in the neonatal unit.