Contamination status of medical ultrasonic probes and coupling agents and survey of their disinfection status

OBJECTIVE To understand the contamination status of medical ultrasonic probes and coupling agents, control cross-infections caused by contamination, explore rapid disinfection methods for medical ultrasonic probes, and provide a basis for formulating control strategies. METHODS From Jul. to Sep. 2021, 28 ultrasound rooms in 11 medical institutions were selected as the research subjects. Through on-site sampling and laboratory testing, the pathogenic bacteria on surface of used body surface ultrasonic probes, as well as coupling agents in use and their bottle mouths, were cultured. The cleaning and disinfection effects of different post-use probe treatment measures(routine paper towel wiping, paper towel wiping + ultrasonic probe disinfector for disinfection, medical surface wet wipe wiping) were compared. RESULTS Seventy-two probes wiped with routine paper towels were collected, with a bacterial colony count exceeding rate of 66.67%. Thirty-eight probes were disinfected with paper towel wiping + ultrasonic probe disinfector, with a bacterial colony count passing rate of 84.21%. Thirty probes were wiped with medical surface wet wipes, with a bacterial colony count passing rate of 66.67%. The cleaning and disinfection effects of B-mode ultrasound probes treated with paper towel wiping + ultrasonic probe disinfector and medical surface wet wipe wiping were statistically significant(P＜ 0.001) compared to routine paper towel wiping. Among the 29 samples of coupling agents in use, the bacterial count exceeding rate was 58.62%, and the fungal count exceeding rate was 78.95%. The bacterial colony count on the coupling agent bottle mouths ranged from 10 to 1.66×10⁴ CFU/bottle, and the fungal colony count ranged from 0 to 3.66×10⁴ CFU/bottle. CONCLUSIONS The bacterial and fungal counts on medical ultrasonic probes and coupling agents seriously exceed the standards, posing a risk of hospital-associated infection. Paper towel wiping + ultrasonic probe disinfector and medical surface wet wipe wiping are suitable methods for rapid cleaning and disinfection of the surface of B-mode ultrasound probes.