Disinfection of Transvaginal Ultrasound Probes by Ultraviolet C – A clinical Evaluation of Automated and Manual Reprocessing Methods

Abstract

PURPOSE: Since pathogens can be transmitted to patients via transvaginal ultrasound probes, it is of particular importance that cleaning and disinfection are performed adequately. This study was designed to do a qualitative comparison of a low-level disinfection technique with disinfectant-impregnated wipes and an automated disinfection technique using ultraviolet C radiation in a clinical setting. MATERIALS AND METHODS: The transvaginal ultrasound probes used in two groups of 160 patients were compared in a prospective controlled study regarding the effectiveness of manual low-level disinfection (Mikrozid sensitive wipes) and automated disinfection using ultraviolet C radiation (Antigermix AS1). Microbiological samples were taken from the whole surface of the probe before and after the disinfection process. RESULTS: Before disinfection, 98.75 % (316/320) of the samples showed bacterial contamination. After automated and manual disinfection, the contamination rates were 34.2 % (54/158, automated) and 40.5 % (64/158, disinfectant wipes) (p > 0.05). Pathogens with the potential to cause healthcare-associated infections, such as Enterococcus faecalis and Klebsiella pneumoniae, were removed completely by both techniques. Manual disinfection showed a lower contamination rate after disinfection of bacteria that usually belong to the vaginal, pharyngeal and skin flora (disinfectant wipes 10.6 %, 11/104, automated 32.5 %, 38/117) (p < 0.001). CONCLUSION: For the clinical routine, automated disinfection with ultraviolet C is a promising technique for transvaginal ultrasound probes because of the simple handling and time efficiency. In our study, this method was completely effective against nosocomial pathogens. However, the study didn't show any significant difference in terms of effectiveness compared to low-level wipe disinfection.