Epidemiological Situation of Antibiotic-Resistant Microorganisms Identified in Patients Hospitalised at the University Teaching Hospital in Bialystok, Poland, in the 2020-2023 Period.

INTRODUCTION: Antimicrobial resistance constitutes one of the key challenges to public health. It is a particularly serious problem in the context of hospital-acquired infections (HAIs). By causing infections that are difficult to treat, multiple-drug-resistant bacteria in the hospital environment often require the use of toxic and costly drugs and prolonged hospital stays, and they result in long-term health consequences for patients, including a high risk of death. This study aimed to assess the epidemiological situation of antibiotic-resistant microorganisms in patients hospitalised at the University Teaching Hospital in Bialystok, Poland, between 2020 and 2023.

METHODS: Data from epidemiological reports covering 15 alert pathogens, including MRSA, VRE, KPC (+), and ESBL (+), were analysed. Their prevalence was assessed in three groups of wards: intensive care, surgical, and non-surgical. Infection and microbiological testing rates were referenced to the number of hospitalisations and patient-days.

RESULTS: A total of 6066 cases of infections caused by resistant microorganisms were identified. The most frequently isolated pathogen was Enterococcus faecium VRE, peaking in 2022 (11.43 per 1000 patients). A marked increase in Klebsiella spp. KPC (+) and Enterobacter spp. ESBL (+) was observed, particularly in the 2021-2022 period. Intensive care units showed the highest infection rate (30-36 per 1000 patient-days). In the 2022-2023 period, infections detected within <72 h of admission predominated, which may indicate prior patient colonisation or intensified screening.

CONCLUSIONS: The rise in infections caused by antibiotic-resistant bacteria requires a high level of microbiological surveillance to be maintained, especially in intensive care units, and preventive measures at hospital admission to be strengthened.