Risk factors for multidrug resistant bacterial infection in infants with bronchopulmonary dysplasia re-hospitalized due to lower respiratory tract infection: a case-control study

To evaluate the epidemiological characteristics and risk factors for multidrug-resistant bacterial infection (MDRI) in infants with bronchopulmonary dysplasia (BPD) readmitted to the hospital due to lower respiratory tract infection (LRTI), providing a basis for the clinical prevention and treatment of MDRI.A retrospective analysis of readmission due to LRTI in infants with BPD within 1 year corrected age from October 2012 to December 2020 was performed. Twenty-nine children with MDRI were selected as the case group, and 80 children without MDRI during the same period served as the control group. We reviewed and collected relevant infants' neonatal hospitalization experience, broad-spectrum antibiotic (BSA) selection, and microbiological data. BSA included carbapenem antibiotics, third-generation cephalosporins and cephalosporin/f3-lactamase inhibitor combinations, and penicillin/f3- lactamase inhibitor (P/BLI) combinations.The length of stay in hospitalized patients with MDRI was significantly prolonged (p < 0.05), and the BSA use rate was high (>94.1%). Single-level factor analyses showed that nosocomial infection and the P/BLI usage rate in the Neonatal Intensive Care Unit (NICU) were related to MDRIs (all p < 0.05). NICU-MDRI, BSA, dual antibiotics, and mechanical ventilation were not significantly associated with MDRIs on readmission (all p > 0.05). Binary logistic regression analysis indicated nosocomial infection as an independent risk factor related to MDRIs (Odds ratio (OR) 5.3, 95% confidence interval (CI) 1.7-16.4).Nosocomial infection remains the most important risk factor for MDRI in BPD infants. For infants with BPD, more cautions should be taken on whether to choose BSA directly based on the bacterial species infected during the NICU or the long-term hospitalization history.