Burden and Determinants of Healthcare-Associated Infections and Antimicrobial Use in a Large Tertiary-Care Hospital in Milan: A Repeated Point Prevalence Survey Study (2022–2025)
1
Faculty of Medicine, University Vita-Salute San Raffaele, Milan, Italy
2
Infection Prevention and Control Team, IRCCS Ospedale San Raffaele, Milan, Italy
3
PhD National Program in One Health Approaches to Infectious Diseases and Life Science Research, Department of Public Health, Experimental and Forensic Medicine, University of Pavia, Pavia, Italy
Popul. Med. 2026;8(Supplement Supplement 1):A3829
ABSTRACT
INTRODUCTION:
Healthcare-associated infections (HAIs) remain one of the most consequential threats to patient safety, driving excess mortality, prolonged hospitalization, and escalating healthcare costs. Their impact is intensified by invasive procedures and antimicrobial resistance. Robust, repeated surveillance is necessary to quantify local burden, track resistance patterns, and support targeted infection control and stewardship strategies. This study provides a multi-year, standardized assessment of HAI prevalence and antimicrobial use in a large tertiary-care hospital in Milan, Italy, generating operationally relevant epidemiological evidence.
METHODS:
We conducted annual cross-sectional Point Prevalence Surveys (PPS) from 2022 to 2025 using the standardized ECDC methodology. The study includes all patients present in the ward at or before 8:00 AM on each survey day. Clinical, microbiological, and antimicrobial use data were systematically extracted from medical records and bedside charts.
RESULTS:
A total of 3,314 patient observations were analyzed across survey rounds. Overall, HAI prevalence was approximately 12%, with significantly higher rates in critical care units (43; 31%) than in general wards (346; 11%). The most frequent HAIs were ventilator-associated pneumonia (15; 4%), catheter-related bloodstream infections (51; 13%), and surgical site infections (51; 13%) consistent with a strong device-associated pattern. Gram-negative organisms accounted for over 30% of isolates, predominantly carbapenem-resistant Klebsiella pneumoniae and Acinetobacter baumannii. Invasive Candida spp. infections were also notable in intensive care settings (7; 5%). Antimicrobial therapy was administered to about 35% of patients, often involving broad-spectrum and last-line agents, including cefiderocol and ceftazidime–avibactam. Major risk factors were invasive devices and prolonged length of stay.
CONCLUSIONS:
This repeated PPS program in a large milanese tertiary hospital demonstrates a substantial and persistent HAI burden driven by multidrug-resistant Gram-negative pathogens and device exposure. Continuous standardised surveillance is essential for guiding targeted prevention measures, refining antimicrobial policies, and adapting local responses to evolving resistance profiles.
Healthcare-associated infections (HAIs) remain one of the most consequential threats to patient safety, driving excess mortality, prolonged hospitalization, and escalating healthcare costs. Their impact is intensified by invasive procedures and antimicrobial resistance. Robust, repeated surveillance is necessary to quantify local burden, track resistance patterns, and support targeted infection control and stewardship strategies. This study provides a multi-year, standardized assessment of HAI prevalence and antimicrobial use in a large tertiary-care hospital in Milan, Italy, generating operationally relevant epidemiological evidence.
METHODS:
We conducted annual cross-sectional Point Prevalence Surveys (PPS) from 2022 to 2025 using the standardized ECDC methodology. The study includes all patients present in the ward at or before 8:00 AM on each survey day. Clinical, microbiological, and antimicrobial use data were systematically extracted from medical records and bedside charts.
RESULTS:
A total of 3,314 patient observations were analyzed across survey rounds. Overall, HAI prevalence was approximately 12%, with significantly higher rates in critical care units (43; 31%) than in general wards (346; 11%). The most frequent HAIs were ventilator-associated pneumonia (15; 4%), catheter-related bloodstream infections (51; 13%), and surgical site infections (51; 13%) consistent with a strong device-associated pattern. Gram-negative organisms accounted for over 30% of isolates, predominantly carbapenem-resistant Klebsiella pneumoniae and Acinetobacter baumannii. Invasive Candida spp. infections were also notable in intensive care settings (7; 5%). Antimicrobial therapy was administered to about 35% of patients, often involving broad-spectrum and last-line agents, including cefiderocol and ceftazidime–avibactam. Major risk factors were invasive devices and prolonged length of stay.
CONCLUSIONS:
This repeated PPS program in a large milanese tertiary hospital demonstrates a substantial and persistent HAI burden driven by multidrug-resistant Gram-negative pathogens and device exposure. Continuous standardised surveillance is essential for guiding targeted prevention measures, refining antimicrobial policies, and adapting local responses to evolving resistance profiles.
| eISSN: | 2654-1459 |
We process personal data collected when visiting the website. The function of obtaining information about users and their behavior is carried out by voluntarily entered information in forms and saving cookies in end devices. Data, including cookies, are used to provide services, improve the user experience and to analyze the traffic in accordance with the Privacy policy. Data are also collected and processed by Google Analytics tool (more).
You can change cookies settings in your browser. Restricted use of cookies in the browser configuration may affect some functionalities of the website.
You can change cookies settings in your browser. Restricted use of cookies in the browser configuration may affect some functionalities of the website.
