Low Level Disinfection Risk
There are several studies that show Low Level Disinfection (LLD) wipes are not as effective as automated High Level Disinfection methods.1
A recent study in a clinical setting confirmed that the LLD procedure alone is unsafe compared to using a HLD method such as UV-C that can reliably inactivate pathogens (HPV). The study stated that automated HLD method is strongly recommended to ensure patient safety. 2
LLD has been proven to be insufficient, as demonstrated by the results of a retrospective cohort study using linked national datasets from Scotland. 3
Various global guidelines recommend High Level disinfection, preferred over LLD for probes classified as semi-critical and critical probes.
Low Level Disinfection Wipes Effectiveness
A recent study in a clinical setting confirmed that the LLD procedure alone is unsafe compared to using a HLD method such as UV-C that can reliably inactivate pathogens (HPV). The study stated that automated HLD method is strongly recommended to ensure patient safety.6
A meta-analysis found procedures using LLD wipes, contamination remained up to 12.9% for pathogenic bacteria and 1% for pathogenic viruses on endocavitary probes. Stating the probability of infection transmission of viral pathogens to patients from these procedures was estimated to be 1-6%.7
High Risk of infection following Low Level Disinfection. In a study conducted at the Gynecology Department of the Lyon University Hospital from July to October, 216 samples were collected before the ultrasound examination, after Low Level Disinfection applied. The results showed:
- 2% (63/216) vaginal probes are detected to be contaminated with Human DNA
- 8% (6/216) vaginal probes are detected to be contaminated with Human papillomavirus HPV and 4/6 with High Risk HPV
- The study concluded that in all hospitals, where LLD is performed, the endovaginal ultrasound procedure must therefore be considered a source for nosocomial High Risk HPV infections. Recommending stringent use of high-level disinfectants.9
Various global guidelines recommend High Level disinfection for endocavity ultrasound probes that are classified as semi-critical/semi-invasive.
Some institutions and medical teams proceed to Low Level Disinfection (LLD) and may not be fully aware of the cross-infection risks after use of an ultrasound probe. However, LLD has been proven to be insufficient, as demonstrated by the results of a retrospective cohort study using linked national datasets from Scotland.3
There have been numerous cases of cross infection risks to patients due to manual ultrasound probe reprocessing:
- Patient contacting hepatitis C virus after transrectal prostate biopsy as part of an individual screening for prostate cancer.
- Patient contracting hepatitis B linked to improper ultrasound transducer disinfection that led to a fatality.3-7
- Bloc S1, Mercadal L, Garnier T, Komly B, Leclerc P, Morel B, Ecoffey C, Dhonneur G. (2011) Evaluation of a new disinfection method for ultrasound probes used for regional anesthesia: ultraviolet C light. J Ultrasound Med. 2011 Jun;30(6):785-8. https://www.ncbi.nlm.nih.gov/pubmed/21632992
- Clinical Guidelines COVID-19 in Australasian Emergency https://ace.mn/aac81
- Health Protection Scotland (HPS), NHS National Services Scotland (2017). NHS Scotland Risk Based Recommendations for the Decontamination of SemiInvasive Ultrasound Probes: Risk of infection following semi-invasive ultrasound procedures in Scotland, 2010 to 2016. Version 1.0.
- Leroy S. Infectious risk of endovaginal and transrectal ultrasonography: systematic review and meta-analysis. The Journal of hospital infection. 2013;83(2):99-106. NAN0046.
- Ferhi K, Roupret M, Mozer P, Ploussard G, Haertig A, de La Taille A. Hepatitis C transmission after prostate biopsy. Case Rep Urol. 2013;2013:797248.
- Maxime Pichon, Karine Lebail-Carval, Geneviève Billaud, Bruno Lina, Pascal Gaucherand and Yahia Mekki (2019) Decontamination of Intravaginal Probes Infected by Human Papillomavirus (HPV) Using UV-C Decontamination System. J. Clin. Med, 8, 1776; doi:10.3390/jcm8111776.
- Leroy, S., et al. (2014). “Impact of vaginal-rectal ultrasound examinations with covered and low-level disinfected transducers on infectious transmissions in France.” Infect Control Hosp Epidemiol 35(12): 1497-1504.
- Medicines and Healthcare products Regulatory Agency (UK), Medical Device Alert Ref: MDA/2012/037.
- Casalegno and et al. High Risk HPV Contamination of Endocavity Vaginal Ultrasound Probes: An Underestimated Route of Nosocomial Infection? PLOS ONE | 2012