The Impact of the COVID-19 Pandemic on Pediatric Microbial Resistance Patterns and Abandonment Rates in Western Romania—An Interdisciplinary Study

<b>Background:</b> The COVID-19 pandemic in Romania exacerbated pediatric antimicrobial resistance (AMR). Overuse of broad-spectrum antibiotics may be related to increased multidrug-resistant bacteria. The main aim of this study was to assess pediatric AMR trends and phenotypes, while a secondary objective was to investigate the potential links with hospital abandonment. <b>Methods:</b> This retrospective study from the Children's Emergency Hospital "Louis Țurcanu", Timișoara, focused on AMR patterns in 2019 pre-pandemic, 2021 pandemic, and 2023 post-pandemic. The following phenotypes were assessed: MRSA, MRCoNS, VRE, ESBL, CRO, MDR, XDR, and PDR. <b>Results:</b> There were 3530 total patients and 6885 total samples. There were 69.92% of the total samples resistant to at least one antimicrobial class, (72.69% in 2019, 67.05% in 2021, 69.16% in 2023). Specifically, resistance towards penicillins remained high across the entire period (57.45-60.93%), while the following classes presented elevated resistance in the pandemic: cephalosporins (42.91%), combination therapies (40.95%), reserve antibiotics (38.89%), and cyclines (13.83%). As for resistance phenotypes, MRSA and MRCoNS peaked during the pandemic (36.08% and 81.43%, respectively) while VRE remained relatively constant. Overall ESBL declined in 2023 to 14.45%, while overall CRO peaked during the pandemic (8.81%). Overall MDR fell during the pandemic (64.47%), while overall XDR peaked in 2019 (9.87%). No PDR cases were observed. Pediatric abandonment was an increasing concern, with regional cases rising from 5.42% (2019) to 9.83% (2023). Compared to the general population, increased antimicrobial resistance in abandoned patients was observed for fluoroquinolones (50.00%), Aminogycolsides (60.00%), reserve antibiotics (70.00%), cephalosporins (60.00%), and urinary antibiotics (60.00%). Resistance to cephalosporins (OR = 5.17, <i>p</i> = 0.0304) and reserve antibiotics (OR = 5.64, <i>p</i> = 0.0049) were key predictors of abandonment risk. <b>Conclusions:</b> The COVID-19 pandemic influenced resistance trends, with notable peaks in MRSA, MRCoNS, and CRO. Post-pandemic patterns suggest continued escalation of resistance. The association between resistant infections and pediatric abandonment highlights the need for robust antimicrobial stewardship and social intervention policies.