Abstract:Objective To understand the outbreak of healthcare-associated infection (HAI) caused by Pseudomonas aeruginosa (P. aeruginosa) and provide reference for targeted prevention and control of the outbreak. Methods P. aeruginosa HAI outbreak events from January 1, 2005 to July 18, 2022 were retrieved from Worldwide Database for Nosocomial Outbreaks and PubMed. The surveyed contents and relevant data were collected in Excel and analyzed. Risk factors for the acquisition and transmission of P. aeruginosa in case-control and cohort studies were evaluated systematically with Meta-analysis. Results From January 1, 2005 to July 18, 2022, 149 HAI outbreaks of P. aeruginosa occurred in 27 countries. Sources of 78 outbreaks were identified, mainly hospital water system (35.90%) and medical equipments (43.59%). P. aeruginosa was mostly transmitted through contaminated medical equipments (34.82%) and water system (32.14%), followed by contaminated hands (16.96%) and environmental object surfaces (16.07%). By taking specific measures to different outbreak sources and strengthening the implementation of basic measures, 79.8% P. aeruginosa HAI outbreaks terminated. Pulsed-field gel electrophoresis, polymerase chain reaction and whole genome sequencing were the most widely used molecular typing methods in outbreak investigation (adopted 86, 21 and 8 times respectively). Meta-analysis results of 15 case-con trol studies showed that length of hospital stay (OR=30.87, 95%CI: 11.89-80.16), carbapenem-resistant antibiotics (OR=7.95, 95%CI: 3.25-19.45) and utilization of medical equipments (OR=6.07, 95%CI: 1.79-23.49) were the main risk factors for P. aeruginosa acquisition and transmission. Conclusion According to the epidemic characteristics and risk factors of the P. aeruginosa outbreak, it is important to focus on monitoring and detecting the contamination of water system and medical equipments in the early stage, and formulate specific intervention measures, thus effectively prevent and control the outbreak of P. aeruginosa infection.