Prevalence, microbiological patterns, and risk factors of hospital-acquired infections in a Tunisian university hospital

Background: This study aimed to determine the prevalence of hospital-acquired infections (HAIs), identify associated risk factors, and describe the microbiological profile of HAIs in a university hospital (UH) in central Tunisia during 2025. Methods: A prevalence study was conducted at a UH in Sousse, central Tunisia. Following the Centers for Disease Control and Prevention definitions, all infections occurring more than 48 hours after hospital admission were classified as HAIs and included in the study. Data collection included a one-day survey per department and a six-day prevalence assessment. Baseline characteristics, clinical features, isolated pathogens, and antimicrobial resistance profiles were recorded. Results: Among 255 eligible patients, 29 had at least one HAI, yielding a prevalence of 11.4%. Bloodstream infections and pneumonia were the most frequent HAIs (32.4% each). Gram-negative bacteria represented 67.4% of all isolates, with Klebsiella pneumonia and Acinetobacter baumannii being the most common (15.2% each). More than half of the isolates (59.4%) were multidrug resistant, including 53.8% of non-fermentative Gram-negative bacilli resistant to carbapenems and 73.3% of Enterobacterales resistant to third-generation cephalosporins. Multivariate analysis showed that prolonged hospital stay (> 10 days) was identified as an independent risk factor for HAIs (AOR = 8.08, 95% CI: 2.54-25.67, p< 0.001). Conclusions: Our findings indicate a high prevalence of HAIs and MDR pathogens. Strict adherence to infection control measures, combined with the implementation of an antibiotic stewardship program at the regional and national levels, is crucial to reducing infections and limiting the emergence of resistant strains.