Hospital-based screening yields 18% CRE colonization prevalence, 20% with universal screening

This systematic review and meta-analysis synthesized data from 89 studies encompassing 116,743 participants across healthcare and community settings. The review compared hospital-based versus community-based screening and universal versus targeted or systematic sampling approaches for carbapenem-resistant Enterobacteriaceae (CRE) colonization. The primary outcome was the pooled CRE colonization prevalence.

The main result was a pooled CRE colonization prevalence of 14% (95% CI: 11%-18%). The analysis showed significant heterogeneity, with an I² of 99.96%. Prevalence varied by year, peaking at 33% in 2017 and declining to 8% in 2023. Geographic variability was substantial, with Vietnam having the highest prevalence (43%) and the United States the lowest (5%).

Prevalence also differed by setting and screening method. Hospital-based screening yielded a prevalence of 18%, and universal screening yielded 20%. These were higher than community-based screening (3%) and targeted or systematic sampling (3%-15%). In meta-regression, hospital setting was the only significant predictor of higher prevalence (coefficient = 0.14, P = .009).

The most common organisms were Klebsiella pneumoniae (52.8%) and Escherichia coli (44.9%). The predominant carbapenemase genes were NDM (45.6%) and OXA-type (36.3%). The review did not report safety or tolerability data, as the studies were observational.

Key limitations included substantial geographic and methodological variability, contributing to the high heterogeneity. The review did not report funding sources or conflicts of interest. The causality note specifies that the association between hospital setting and higher prevalence is based on a meta-regression coefficient and does not imply direct causation.

These results compare to prior landmark studies by highlighting the global burden of CRE colonization and the importance of setting-specific surveillance. The declining trend from 2017 to 2023 may reflect improved infection control, but the data are observational.

Clinical implications include the need for standardized surveillance and targeted control strategies, with molecular surveillance essential to monitor resistance determinant evolution. Practice decisions should account for the high variability in reported rates.

Unanswered questions include the drivers of the declining prevalence trend, optimal screening protocols for different settings, and the impact of specific carbapenemase genes on clinical outcomes.