MDRO detection rates increased during COVID-19 policy phases in Chinese inpatients with hospital-acquired infections.

BackgroundMultidrug-resistant organism (MDRO) infections are a major global health threat. The COVID-19 pandemic and related containment policies may have altered hospital infection epidemiology and the distribution of MDROs.MethodsIn this retrospective cohort study, clinical and microbiological data from 2,669 adult inpatients with culture-confirmed hospital-acquired infections between 2013 and 2023 were analyzed. MDROs were defined per CLSI guidelines. The study period was stratified into pre-pandemic, strict containment, and post-adjustment phases. Multivariate logistic regression was used to identified factors associated with specific MDRO infections.ResultsThe overall MDRO detection rate increased from 36.9% to 56.4% during the strict containment. CRAB, which had previously been the dominant resistant pathogen, was progressively overtaken by CRE, while Klebsiella pneumoniae became the predominant species in 2022 (40.0%).Bloodstream infections increased from a pre-pandemic peak of 24% to 32% during the strict containment phase. Male sex, age≥60 years, and prolonged hospitalization (>14 days) were associated with distinct distribution patterns of CRAB and CRE infection. In multivariable analyses, mechanical ventilation was associated with increased odds of CRAB infection (aOR=2.07, 95% CI: 1.36-3.16), while urinary catheter use was associated with increased odds of CRE infection (aOR=1.49, 95% CI: 1.06-2.09) but lower odds of CRAB infection (aOR=0.64, 95% CI: 0.46-0.89). Endotracheal intubation was associated with increased odds of VRE infection (aOR = 5.84, 95% CI: 1.10-30.9).ConclusionsHospital MDRO epidemiology shifted substantially across the COVID-19 policy phases, with CRE emerging as the dominant resistant pathogen. Specific invasive procedures showed pathogen-specific associations, supporting risk stratification and more targeted infection prevention strategies in high-risk hospitalized patients.