EVALUATION OF THE EFFECTIVENESS OF DISINFECTION MEASURES IN HOSPITALS

Abstract

Intro: Effective prevention of outbreaks of healthcare associated infections (HAI) remains one of the most acute problems in medical facilities. One of the infection prevention and control (IPC) measures is the use of effective disinfectants. The aim of the study was to analyze of the effectiveness of disinfection of epidemiologically significant hospital equipment. Methods: During 2019 - 2021 we carried out sampling from the same epidemiologically significant items of equipment in a hospital in Rostov-on-Don (156 samples) with an interval of 1 year. The sensitivity of gram-positive flora and non-fermenting bacteria to disinfectants was analyzed. Findings: 108 strains of potential causative agents of HAI were isolated. The dominance of gram-positive microorganisms, represented mainly by the genus Staphylococcus, was identified (from 62.2% to 82.6%). Representatives of nonfermenting Gram-negative bacteria (NFGNB) (Pseudomonas trivialis, Pseudomonas stutzeri, Pseudomonas veronii, Acinenetobacter lwoffii, Shevanella frigidimarina, Stenotrophomonas maltophilia) were identified in 8.7% to 22.25% of samples. An increase in the proportion of Staphylococci at sampling points from 31.1% in 2019 to 55.5% in 2020 was recorded. Further we used the disinfectants with maximum antimicrobial activity. When re-examined in 2021, the proportion of Staphylococcus spp. and NFGNB decreased to 37.% and 8.7%, respectively. The proportion of sterile points (without growth of microorganisms) increased from 24.4% in 2019 to 73.7 in 2021. Discussion: A significant increase in the proportion of Staphylococcus spp. in 2020 possibly associated to the developing of resistance to disinfectants, which were used more than 2 years. NFGNBs also showed a tendency towards the emergence of resistance, their proportion increased in 2020 to 22.2% compared to 17.8% in 2019. Conclusion: The increase in the number of sterile points during the observation period indicates the effectiveness of the disinfection as a part of IPC measures. This was also facilitated by the rotation of disinfectants in 2021 based on the disinfectant activity assessment.