Postoperative risk of infection with klebsiella in adults – a retrospective case–control study

Background: Hospital-acquired infections with Klebsiella spp. and emerging multi-drug-resistant strains are a persistent concern. Identifying high-risk groups is crucial for the evaluation of preventive interventions such as vaccines. We determined the incidence and developed prediction models for postsurgical klebsiella infections in adult elective surgery patients. Methods: This multi-centre retrospective case–control study, in seven European hospitals, included patients ≥50 years old who underwent elective surgery between 2012 and 2021. Using multi-variable logistic regression, we modelled the risk of postsurgical klebsiella infection and investigated trial enrichment scenarios. Results: Of 139,778 eligible surgeries identified, 1781 were included: 840 patients with postsurgical klebsiella infection and 941 without. The incidence of postsurgical klebsiella infection was 1.38% (95% confidence interval 1.24–1.54%). Pre-surgical klebsiella colonization, gastrointestinal surgery, abdominal surgery, trauma surgery and chronic cardiovascular disease were independent predictors of postoperative klebsiella infection. Minimally invasive surgery and peri-operative antibiotic prophylaxis predicted a lower risk. Trial enrichment simulation indicated a 72% reduction in required participants when enrolling patients with a predicted risk above 2%. Conclusions: A multi-variable model incorporating klebsiella colonization status and clinical factors can accurately predict klebsiella infections in elective surgery patients. This model can select high-risk patients, enhancing the efficiency of phase-III trials of preventive interventions, including vaccination.