Prevalence, Risk Factors, and Clinical Outcomes of Hypervirulent Klebsiella pneumoniae Strains among Klebsiella pneumoniae Infections: A Systematic Review and Meta-analysis

Aim and background: Hypervirulent Klebsiella pneumoniae (HvKp) is a virulentstrain associated with invasive infections. While initiallycommunity-acquired, hospital-acquired HvKp (HA-HvKp) and carbapenem-resistant HvKp (CR-HvKp) are increasingly reported.This meta-analysis evaluates the prevalence, risk factors, and clinical outcomes associated with HvKp, including CR-HvKp and HA-HvKp, among Kp infections. Methodology: A systematic search of PubMed, Scopus, Embase, and Cochrane Library was conducted until December 2024. Observational studies comparing HvKp vs classical Kp (cKp), CR-HvKp vs carbapenem-sensitive HvKp (CS-HvKp), and HA-HvKp vs community-acquired HvKp (CA-HvKp) were included. Quality was assessed using the Joanna Briggs Critical Appraisal Tool, and pooled prevalence and odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Results: Fifty studies with 6,663 participants were included.The HvKp prevalence was 33.0%, with most studies from Asia, predominantly China. Temporal analysis revealed an increase in HvKp prevalence (27.7% in 2006-2018 to 38.5% in 2019-2024). The CR-HvKp prevalence rose from 9.5% to 16.5% (2016-2024). The HA-HvKp prevalence increased from 25.9 to 47.1%. Key risk factors included diabetes mellitus (OR = 1.56), CA-Kp (OR = 2.59), and hypermucoviscous (HM)-phenotype (OR = 29.79). Complications included liver abscess (OR = 6.35), metastatic spread (OR = 4.74), meningitis (OR = 11.14), and septic shock (OR = 1.30). Mortality was higher in HvKp infections but not statistically significant (p = 0.219). HA-HvKp and immunosuppression were significant CR-HvKp risk factors, with CR-HvKp showing higher mortality. Conclusions: Diabetes mellitus, CA-Kp infections, and HM-phenotype are significant risk factors for HvKp. The rising prevalence of CR-HvKp and HA-HvKp highlights the need for early detection, infection control, and targeted treatment strategies.