Hypervirulent Klebsiella pneumoniae Infections: A Systematic Review of Clinical, Microbiological, and Outcome Data From Reported Cases.

Hypervirulent Klebsiella pneumoniae (hvKp) has been increasingly reported in association with invasive infections and multi-organ involvement. This systematic review followed PRISMA guidelines and was registered in PROSPERO (CRD420251060200). PubMed, Scopus, and Web of Science were searched for articles published between 2000 and 2025. We conducted a review of published reports to summarize the clinical, microbiological, and outcome characteristics of reported hvKp infections. Studies reporting individual-level data were included, and descriptive analyses were performed. A total of 778 cases from 376 reports were included. Bloodstream infection and liver involvement were among the most frequently reported clinical features, and multi-organ involvement was commonly described. Virulence factors, including siderophores and capsular types, were frequently reported; however, microbiological findings varied across studies. Among cases with available data, 82.1% had origin from or travel to endemic regions and, 43.1% had diabetes mellitus. This systematic review provides a descriptive overview of reported hvKp infections, highlighting frequently reported clinical and microbiological patterns. However, the findings are based on heterogeneous and predominantly severe cases and should be interpreted with caution. Further studies using standardized definitions and systematically collected data are needed to better characterize hvKp infections.