Evaluating the Effectiveness of Two Disinfection Processes on Bacteria Causing Nosocomial Infections in the Intensive Care Units of an Educational, Research, and Treatment Hospital in Semnan, Iran

Background: Disinfection is the process of killing pathogenic microorganisms on non-living surfaces. Selecting and using appropriate and standard disinfection methods can significantly reduce nosocomial infections. Objectives: This study aimed to determine the effectiveness of the disinfection process on bacteria causing nosocomial infections in an educational, research, and treatment hospital located in Semnan, Iran in 2021. Methods: In 2021, 156 samples were collected and analyzed for microorganism growth in a suitable culture medium from the surgical ICU, CCU, and internal wards of men at Kosar Hospital in Semnan. Samples were taken during three work shifts (morning, evening, and night) from breakfast tables, suction devices, ventilators or biopsy equipment, and rods at the patient s bed. Results: Before the disinfection process, 81.8% (27 cases) of the samples tested positive for various microorganisms. The most commonly grown microorganisms were Klebsiella (33.3%) and Staphylococcus (18.2%). The highest percentage of microorganisms developed after disinfection with Sayasept and sodium hypochlorite were seen at two and a half hours (26.3%) and two hours (26.7%), respectively. Disinfection with sodium hypochlorite significantly reduced the number of microorganisms grown in the post-disinfection period compared to before (P-value = 0.042), whereas disinfection with Sayasept did not show a statistically significant effect (P-value = 0.132). Conclusions: Using sodium hypochlorite greatly decreased the number of microorganisms in the post-disinfection period, despite the high number of microorganisms present before disinfection in the analyzed wards. It is vital to implement hygienic policies that ensure proper disinfection of hospital surfaces and provide adequate training, particularly emphasizing the use of sodium hypochlorite.