Prevalence of Nosocomial Infections in ICU Departments of Tehran University Hospitals During and Before the COVID-19 Pandemic

Background: Hospital-acquired infections (HAIs) in intensive care units (ICUs) remain a significant cause of preventable morbidity and mortality worldwide. This study aimed to assess the prevalence of nosocomial infections in ICUs of Tehran University of Medical Sciences hospitals over three years during the COVID-19 pandemic and compare it with the pre-pandemic period. Methods: A retrospective descriptive-analytical study was conducted using hospital infection control records from 2017–2021. Data were obtained from ICU departments across multiple hospitals affiliated with Tehran University of Medical Sciences. Variables analyzed included type of infection, causative organism, patient demographics, mortality, and length of hospital stay. Statistical analyses were performed using SPSS version 24. Results: Among 20,942 ICU patients analyzed, 59.5% were admitted before and 40.5% during the COVID-19 pandemic. Ventilator-associated events (VAE) were the most frequent HAIs across all years. The mortality rate due to HAIs increased from 31.8% pre-COVID to 42.6% during COVID (p<0.001). The most prevalent organisms were Klebsiella (26.5%), Acinetobacter (19.9%), and E. coli (12.7%). Antibiotic resistance patterns showed a mild increase in resistance during COVID, though not statistically significant. Conclusion: The prevalence of ICU-acquired infections remained consistent before and during the COVID-19 pandemic, though mortality increased. Continuous surveillance and reinforcement of infection control measures are vital to mitigate HAIs and antimicrobial resistance. Information & Authors Information Version history Copyright This work is licensed under a Non Exclusive No Reuse License.

Authors Metrics & Citations Metrics Article Usage 171views 98downloads Citations Download citation Ibrahim, Anoosha Gull, Hussain. Prevalence of Nosocomial Infections in ICU Departments of Tehran University Hospitals During and Before the COVID-19 Pandemic. Authorea. 23 October 2025. DOI: https://doi.org/10.22541/au.176124794.45219128/v1 DOI: https://doi.org/10.22541/au.176124794.45219128/v1 If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download. For more information or tips please see 'Downloading to a citation manager' in the Help menu.