Prevalence and Determinants of Hospital‐Acquired Infections in Intensive Care Units Before and After the COVID‐19 Pandemic: A Retrospective Descriptive Surveillance Study at a Tertiary Care Hospital in Iran

Background and Aims Hospital‐acquired infections (HAIs) in intensive care units (ICUs) cause significant morbidity, mortality, and costs. The COVID‐19 pandemic intensified infection control, but its effect on HAI prevalence and patterns is unclear. This study compared HAI prevalence, types, and causative agents in an Iranian tertiary hospital before and after COVID‐19. Methods A retrospective descriptive‐analytical study was conducted on ICU patients admitted to Taleghani Hospital, Kermanshah, Iran, between 2019 and 2020. Demographic, clinical, and microbiological data were collected from hospital records. Associations between categorical variables were assessed using Chi‐square or Fisher's exact tests, and continuous non‐normally distributed variables were compared using the Mann–Whitney U test, with p < 0.05 considered statistically significant. Results Among 1778 ICU admissions, 301 cases of HAIs were identified, yielding an overall prevalence of 16.9%. The prevalence decreased from 131/718 (18.2%) in 2019 to 170/1060 (16.0%) in 2020. Gram‐negative aerobic bacteria were the predominant pathogens in both years (128/131 [97.7%] vs. 163/170 [95.9%]), while fungal and other infections emerged only in 2020. Ventilator‐associated events (VAE) were the most frequent infection type, followed by pneumonia, urinary tract infections (UTIs), surgical site infections (SSIs), and bloodstream infections (BSIs). While VAE and pneumonia decreased in 2020, UTIs and BSIs increased. ICU2 consistently reported the highest infection rates, whereas ICU3 experienced a marked rise in infections in 2020. Statistical analysis confirmed significant associations between infection occurrence and gender, ICU ward, and Gram‐negative bacterial infections ( p < 0.05). Conclusion Despite strengthened infection control during COVID‐19, HAIs particularly Gram‐negative infections and VAE remain prevalent in ICUs. Continuous surveillance and targeted interventions are essential to reduce their burden.